The document describes a family of microinstruments being developed for use in space missions. The instruments use magneto-optic thin film sensors to perform tasks like non-destructive testing of spacecraft components, detecting electromagnetic fields, monitoring biomagnetic fields, and optical signal processing. Each sensor is based on a proprietary Fe-Ga thin film material and uses polarized light and a spatial light modulator. The sensors can detect magnetic fields as small as 10-7 Oersted and have applications in areas like defect detection, energy generation, medicine, and neural networks. The technology provides advantages over existing non-destructive testing methods by directly imaging defects in real-time with high resolution and low false readings.
Matter, Inc. describes a plasmonic technology that can substantially improve the efficiency of thin film solar cells. Simulation results show the technology is capable of increasing short circuit current by almost 50% through enhanced light trapping. The plasmonic structures are robust, scalable to deposit, and enable simultaneous light concentration and charge extraction. An ongoing development cycle aims to optimize coatings and fabricate prototype thin film cells to validate the performance enhancements predicted by simulations.
III-Nitride Semiconductors based Optical Power Splitter Device Design for und...IJECEIAES
In this paper, we introduce III-nitrides based 1× 4 optical power splitter for underwater optical communication applications. To the best of our knowledge, this is a first study for the design of multimode interference (MMI) and four-branch taper waveguide based on GaN/sapphire. The microstructure of GaN semiconductor grown by Metalorganic Chemical Vapor Deposition (MOCVD) on (0001) sapphire reported. The numerical experimental is conducted using the 3D FD-BPM method. The results showed that the optical power splitter has an excess loss of 0.013 dB and imbalance of 0.17 dB. The results open the opportunity for the future device using this technology for the underwater application.
Thermal response of skin diseased tissue treated by plasmonic nanoantenna IJECEIAES
The thermal distribution in the diseased tissue treated by different methods faces the problem of an uncontrollable defused heat. In the present article, we use a plasmonic bowtie nanoantenna working in the near infrared region to enhance the temperature confinement in the tissue. The Computer Simulation Technology Studio Suite package version 2019 was used to execute the design of both plasmonic nanoantenna and the tissue. Gold nanostructure and silicon carbide dioxide are the components the plasmonic nanoantenna in the bowtie shape. The results showed that the distance between the tumor tissue and the antenna is important to determine the intensity field where the maximum field is 5.9*10 V/m at a distance of 100 nm. The maximum specific absorption rate is 1.92*10 11 W/kg at a similar distance which gives a higher temperature in the tissue of 580 C o . It is concluded that from the obtained results that the near infrared (1064 nm) resonance wavelength is recommended in the treatment of cancer cell by plasmonic bowtie nanoantenna because higher intensity field is generated. The closer distance to the nanoantenna gives higher temperature in the tissue while the temperature gradually decreases in the tissue till 400 nm where no valuable temperature was detected. 7
Studying photnic crystals in linear and nonlinear mediaIslam Kotb Ismail
This document outlines a presentation on photonic crystals and nonlinear optics. It discusses:
- What photonic crystals are and how they inhibit light propagation through periodic refractive index patterns. Maxwell's equations are used to model light propagation in these structures.
- Common photonic crystal topologies in 1D, 2D and 3D, including photonic bandgap properties. Applications like mirrors and waveguides are mentioned.
- How nonlinear optical effects like the Pockels and Kerr effects modify a material's refractive index with an electric field. Nonlinear photonic crystals combine these effects.
- The document concludes by proposing nonlinear photonic crystals can act as optical limiters that regulate light transmission intensity.
A review on graphene based light emitting functional devicesJournal Papers
The document reviews recent developments in graphene-based light-emitting devices. It discusses how light emissions from graphene have been observed through thermal emission, electroluminescence, and plasmon-assisted emission. The review covers the device structures, fabrication methods, optical and electronic properties related to these light emission mechanisms. It also discusses potential applications for graphene light emitters and current technological challenges in the field.
The document describes Nanonics Imaging Ltd's Nanonics Optometronic 4000 system, which provides an integrated platform for optical, electrical, and thermal characterization at the micro and nanoscale. The system uniquely combines atomic force microscopy (AFM) with near-field scanning optical microscopy (NSOM) using specialized fiber optic probes. This allows for correlated structural and optical measurements in the near and far field. The system is positioned to be a leading platform for photonics characterization in the 21st century, known as the Century of Photonics.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
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journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals
Applications of atomic force microscope(by kanupriya)KANUPRIYASINGH19
The document discusses applications of atomic force microscopy (AFM) in physical and materials sciences as well as nanotechnology. Some key applications discussed include:
1) Measuring surface roughness of materials like metals, polymers, and medical implants to understand properties.
2) Probing mechanical properties like hardness of polymer films and crystals at the nanoscale.
3) Imaging crystal structures with atomic resolution to study arrangements of atoms.
In nanotechnology, AFM is used for measuring nanoparticles, studying mechanical properties of nanotubes, and constructing nanodevices through direct manipulation of components.
This document summarizes the results of a simulation study investigating light absorption in organic solar cells with smooth and pyramidal textured surfaces. The study first optimized a flat organic solar cell structure by simulating the effects of varying each layer's thickness on short-circuit current and quantum efficiency. The optimized flat cell achieved 13.65 mA/cm2 short-circuit current and 84% quantum efficiency at 640 nm. It then proposed a pyramid textured surface to enhance light trapping and absorption compared to a smooth surface. The effects of period and height of the pyramids were analyzed to validate the light trapping model.
Photonics devices use photons to transmit, control, manipulate and store data. They offer benefits like greater energy savings and communication distances due to their unique characteristics, such as being less sensitive to interference. Light-emitting diodes (LEDs) are semiconductor light sources used as indicator lamps and increasingly for lighting. They have advantages over other light sources like lower energy use, longer lifetimes, and smaller size. Photodiodes are PN junction diodes designed to detect photons and convert light into an electrical current. Laser diodes are semiconductor devices that produce coherent light when current passes through and are used to convert electrical signals into light signals.
The document discusses progress in extreme ultraviolet lithography (EUVL) for semiconductor fabrication. It covers:
1) EUVL is a promising next-generation lithography technique needed to continue transistor scaling below 7nm, but faces challenges like resolution, line width roughness, and sensitivity.
2) Novel resist materials without chemical amplification are being developed to overcome issues with chemically amplified resists at small scales. Examples discussed are sulfonium-containing polymers that change solubility upon EUV exposure.
3) Experiments show these new resists can resolve lines as small as 16nm and complex nanostructures when exposed with EUV lithography. Continued improvements aim to enhance sensitivity.
Graphene plasmonic couple to metallic antennaxingangahu
1. The document proposes a novel nanoantenna configuration using a metallic dipole antenna on top of an insulator layer, with a graphene sheet attached below the insulator.
2. By modifying the chemical potential of the graphene sheet using an applied gate voltage, the dispersion relation and optical conductivity of graphene can be tuned.
3. This allows the in-phase and out-of-phase coupling between the metallic plasmonics and graphene plasmonics to modify characteristics of the metal-graphene nanoantenna like its resonance frequency, near-field and far-field responses.
Optical Quilt Packaging (OQP) is a novel technique for efficient optical coupling between chips for modular mid-infrared sensors. It uses lithographically defined interdigitated copper nodules on the edges of chips to align waveguides with sub-micron accuracy. Simulations show coupling losses better than 6 dB for gaps under 4 microns. Initial OQP structures were fabricated with a 1 micron misalignment and 10 micron gap between Ge-on-Si waveguides on separate chips. Future work will measure optical losses between aligned QCL and waveguide chips coupled using OQP.
Improving Splitting Efficiency in Photonic Crystal WaveguideIJERA Editor
“Photonic Crystals (PCs)” are dielectric structures with periodic spatial alternations of refractive index on the
scale of the wavelength of light. Many optical devices, based on PCs, have been proposed. There are
multiple ways by which equal amount of power of incoming signals can be divided into two, three and
four output channels; for example using multiple coupled photonic crystal waveguides, directional coupling and
cascaded multimode PC waveguides. Ideally, the splitter should divide the input power equally into the output
channels without significant reflection or radiation losses and should be compact in size. In this thesis I
have proposed the optical power splitting using Y-junction. The optical modeling of this proposed structure
was investigated by finite difference time domain (FDTD) simulation. The goal was to achieve equal power at
each output channel with broad spectrum around the target wavelength with low loss.
1. Surface plasmon resonance (SPR) involves the resonant oscillation of conduction electrons stimulated by incident light at a metal-dielectric interface. SPR can be used to detect changes in refractive index within 300 nm of a sensor surface.
2. There are three main configurations for SPR sensors: prism-based, grating-based, and optical waveguide-based. Factors that affect SPR include the type of metal used, the structure and composition of the metal surface, and the properties of the incident light.
3. SPR biosensors can be used for applications in the dairy industry like detection of antibiotics, proteins in milk powder, food-borne pathogens like Listeria monocytogenes and Salmonella.
This document discusses electron beam lithography techniques used in nanoscale fabrication. It begins with an overview of nanofabrication and conventional photolithography limitations. Then it describes electron beam lithography, including how the lithography system works, common techniques like direct writing and projection printing, types of electron beam resists, and benefits like high resolution. Challenges with the proximity effect and defects are discussed. Recent competing techniques like nanoimprint lithography are compared. Applications include fabrication of molds, tunnel junction devices, and use in x-ray and dip-pen nanolithographies. In conclusion, electron beam lithography continues to be important for nanoscale device fabrication.
This document describes a study that explores using smartphone magnetometers for science applications on CubeSats. It finds that while smartphone magnetometers are less precise than research-grade sensors, they are able to detect signatures of field-aligned currents and auroral/equatorial electrojets through signal processing techniques. The study simulates data collection by a CubeSat passing through an electrojet current sheet using magnetometer noise from a smartphone. After applying filtering, decimation, and matched filtering with a reference signal, the electrojet signature is detectable in the simulated data, demonstrating the feasibility of using low-cost smartphone sensors for space science measurements on small satellites.
Victor Pashkov's CV outlines his education and experience developing optical and electronic instruments, including a LIDAR system, improving the GLONASS navigation message, simulating an optical electronic instrument with CCD matrices for space navigation, designing an optical switch and laser projection system, and managing projects for an optical projection TV and LED backlight unit for LCD displays.
The document discusses various nanofabrication techniques. Photolithography has limitations based on the optical diffraction limit. Electron beam lithography allows for higher resolution down to 5 nm but is slow and expensive. Soft lithography uses elastomeric stamps to transfer self-assembled monolayers in a parallel, low-cost manner via techniques like nanoimprint lithography and microcontact printing. Scanned probe techniques like atomic force microscopy and scanning tunneling microscopy can directly oxidize surfaces on the nanoscale.
The document discusses electron backscatter diffraction (EBSD), including a brief history, the principal system components, how patterns are formed, operating conditions, and uses. EBSD allows determining crystallographic orientations, misorientations, texture trends, grain size, boundary types, and phases. It works by detecting Kikuchi patterns formed by elastic backscatter of electrons from tilted crystalline samples, and analyzing the patterns to determine crystallographic data. EBSD is now widely used to quantitatively characterize microstructures and textures in materials.
Este documento evalúa el uso del bagazo de caña de azúcar como combustible sustituto del petróleo. Explica que el bagazo es un residuo de la molienda de caña que contiene fibra y jugo. Tiene un alto contenido de carbono y bajo contenido de cenizas, lo que lo hace un buen combustible. Analiza las ventajas económicas y ambientales de usar bagazo en lugar de petróleo para generar vapor en centrales azucareras, concluyendo que el bagazo es una alternativa viable y
Sergio cavalcante apps de consumo de ap is de internet para windows phoneINdT
This document discusses consuming APIs from the internet in Windows Phone apps. It covers technologies like SOA and web services that enable API access. Examples are given of popular APIs from services like Bing, Twitter, Facebook, and Amazon that can be accessed. The document concludes with contact information for the presenter in case the audience has any other questions.
The document discusses the future of activity tracking technology. It describes how tracking will evolve from measuring basic physical movement and vital signs to more advanced monitoring of how and why people move through sensors embedded in clothing. These new sensors will provide richer data on biomechanics, muscle activity, pressure distribution and social interactions to enable improved performance tracking, medical monitoring and interactive experiences. The future of tracking will be more personalized, customized and integrated into daily life through wearable and metabolically-powered devices that are minimally invasive.
100 procent vývojářů to dělá zle. V 5 lidech jsme zabojovali a já po vyhodnocení zjistil, jak ve 3 krocích zdokonalit kteréhokoliv vývojáře.
Více na http://webexpo.cz/praha2012/prednaska/souboj-frameworku/
Andreas Erdel (www.andreas-erdel.com), translater, Swedish, German, English, ...AndreasErdel
Andreas Erdel is a sworn translator who specializes in translating between German, English, French, and Swedish. He offers translation services, proofreading, and language training. He emphasizes his individual approach and experience in the field. His translation work is thorough and dependable. He provides customized quotes and ensures client satisfaction.
The document lists the speakers, hosts, sponsors, and supporters of the 2010 Women Grow Business Boot Camp event on June 19, 2010. It provides contact information including names, company websites, phone numbers, and email addresses for over 25 individuals involved in the event. The event was sponsored by Network Solutions and Steptoe & Johnson LLP.
Ameya Kanitkar: Using Hadoop and HBase to Personalize Web, Mobile and Email E...WebExpo
This document discusses using Hadoop and HBase to build content relevance and personalization systems for big data applications. It provides an overview of Hadoop and HBase, and how they can be used together. As a case study, it describes how Groupon uses Hadoop and HBase for their deal relevance and personalization systems, including storing user data in HBase and running recommendation algorithms using MapReduce.
In order to get a good resale value of your car, you shouldn’t forget to take proper care of the car paint because it enhances the vehicle looks and values considerably. UV rays, dust, and debris gradually deteriorates your vehicle paints. Go through the slide to get the complete knowledge about how to prevent the paint damage resulting from oxidation as the oxidation process makes your car looks older than it actually is.
Programación cuartos de final vi campeonato nacional femenino sub 19alcaldiadetamesis
La Federación Colombiana de Fútbol de Salón es una entidad sin ánimo de lucro fundada en 1974 que organiza el VI Campeonato Nacional Femenino Sub-19 en Támesis, Antioquia. El torneo consiste en una fase de grupos, cuartos de final a disputarse el 6 de diciembre, semifinales el 7 de diciembre y la final el 8 de diciembre donde se enfrentarán los ganadores de cada semifinal para determinar al campeón.
The document summarizes the editing process for a video project. It involved splitting video clips of an interview into sections based on the answers to different questions. The clips were then lined up with the corresponding questions on the timeline. Images collected were added during cuts in the video clips. Final touches included end credits, transition effects between clips and images, and adding a background soundtrack.
El documento presenta 8 ejercicios de funciones que involucran hallar dominios, valores de x para que funciones sean iguales a cero, y graficar funciones. Se resuelven ejercicios como hallar el dominio de funciones racionales, encontrar valores de x para que funciones sean iguales, y graficar funciones como parábolas, hipérbolas y racionales.
The ten commandments of Apex are the fundamental rules that good Force.com developers always use when developing. Join us to learn the common pitfalls that often cause difficulties for new developers to the platform so you can architect and develop top-notch Force.com applications.
Have you been thinking about what your next steps are in your career journey? Understanding Salesforce is a skill that can lead to a variety of industries and positions. Attend this session to learn how to build out your personal career map.
Este documento describe el álgebra de Boole y las funciones lógicas. Explica conceptos como proposiciones lógicas, funciones booleanas básicas como AND, OR y NOT, postulados y propiedades del álgebra de Boole, representación circuital de funciones lógicas, y formas de representar funciones lógicas como suma de productos y producto de sumas. El documento provee una introducción completa al álgebra de Boole y las funciones lógicas fundamentales.
SOCIAL MEDIA ADOPTION BY U.S. SMALL BUSINESSES DOUBLES SINCE 2009Web.com
American small businesses are pushing the limits on new ways to improve efficiency in the prolonged downturn, including a steady increase in social media adoption. The third wave of the Small Business Success Index™ (SBSI), sponsored by Network Solutions® and the Center for Excellence in Service at the University of Maryland’s Smith School of Business, reports social media adoption by small businesses has doubled from 12% to 24% in the last year.
This document proposes a technology using magneto-optic thin film sensors to study magnetic fields in deep space through wide-area arrays deployed by spacecraft. Each sensor would measure local magnetic fields and disturbances, with data communicated to reconstruct magnetic activity over large regions. The arrays could also control large space systems through parallel computing principles. The sensors use bismuth-substituted iron-garnet films that respond to magnetic fields through the magneto-optic Faraday effect, providing high sensitivity and domain wall velocity. Deployed arrays would allow unprecedented magnetic mapping beyond spacecraft's direct reach.
This document discusses a novel magneto-optic sensor called the MODE sensor that can be used for non-destructive testing of structural integrity. The MODE sensor uses thin films made of rare earth and transition metal oxides that have high magneto-optic properties, allowing it to detect cracks, fissures, and corrosion in structures. A portable system has been designed using this sensor to allow real-time inspection of bridges, fuel tanks, and other metal structures. The system includes image processing and pattern recognition capabilities to help identify defects.
This document summarizes research on using magneto-optic imaging for non-destructive testing of metal structures. It describes developing new thin-film sensors with improved sensitivity, integrating the sensors and image recognition algorithms into a portable system, and applying a neural network algorithm called SONON to enhance defect detection in images. Laboratory experiments demonstrated the new sensors could detect smaller defects than previous methods. The overall aim is more accurate, automated inspections using portable, wearable equipment.
This document discusses the study of optical characteristics of nano-antennas. It begins by introducing metallic optical nano-antennas and how their properties depend on geometry and materials. Nano-antennas have potential applications in nanophotonics by confining electromagnetic waves at metal-dielectric interfaces at scales smaller than the light wavelength. Different types of nano-antennas are presented, including dipole antennas and spiral antennas. The document discusses several key optical properties of nano-antennas including their polarization sensitivity, directional sensitivity, and applications in areas like plasmonic sensing and biochemical detection. In conclusions, nano-antennas represent an area of light detection where both technological and fundamental problems need to be addressed through further research.
I. Massive and fast inversions provide high resolution inversion of MobileMT data into resistivity-depth models without limitations on frequency or station numbers. Results are used to assess data quality and compile databases for further analysis.
II. Detail and goal-oriented inversions use adaptive finite element modeling focused on specific zones, providing more detailed models of complex structures.
III. Forward modeling estimates the detectability of exploration targets using MobileMT, helping evaluate the technology's capability for specific geology.
INSPECTION OF PROFILED FRP COMPOSITE STRUCTURES BY MICROWAVE NDEjmicro
Fiber reinforced polymer (FRP) composites are employed in various applications of aerospace and defence industry. FRP composites are preferred as major structural parts due to their high stiffness strength and light weight.Non-destructive evaluation (NDE) plays an important role in assessing the quality and health monitoring of FRP composite structures during their manufacturing and in-service period.Different NDE techniques, such as ultrasonics, thermography, X-ray radiography, etc are employed for evaluating the quality of the composite structures.Microwave non-destructive evaluation (MWNDE) is an emerging NDE technique for characterizing and inspecting dielectric structures. Microwave NDE finds application in the areas of dielectric material characterization, determining thickness variation, defect detection and bond quality inspection.Inspection of profiled FRP composite structures by near-field reflection microwave NDE technique is presented in this paper. Application of Microwave NDE for bond quality inspection of FRP composite structures and thickness variation of composite structures is discussed. Results of inspected profiled composite structures by swept frequency reflection microwave NDE technique in the frequency range of X-band and Ku-band respectively are presented
Dr. Gernot S. Pomrenke presents an overview of his program, Photonics and Optoelectronics, at the AFOSR 2013 Spring Review. At this review, Program Officers from AFOSR Technical Divisions will present briefings that highlight basic research programs beneficial to the Air Force.
During the last decades a large effort has been invested in the development of a new
discipline devoted to benefit from optical excitations in materials where metals are
key element (Plasmonics). We will make an introduction on this topic below, but let’s
anticipate that two application areas are sensing and information technologies.
The following height extended abstracts, presented during the one-day NANOMAGMA
Symposium (Bilbao, Spain – April 13, 2011 reflects some of the latest developments on magneto-plasmonics.
In 2010 and 2011, the nanoICT project (EU/ICT/FET Coordination Action) launched
two calls for exchange visits for PhD students with the following main objectives: 1.
To perform joint work or to be trained in the leading European industrial and academic research institutions; 2. To enhance long-term collaborations within the ERA; 3. To
generate high-skilled personnel and to facilitate technology transfer;
The first outcome report was published in the issue 22 (August 2011) and this edition
contains four new articles providing insights in relevant fi elds for nanoICT.
We would like to thank all the authors who contributed to this issue as well as the European Commission for the financial support (projects nanoICT No. 216165 and NANOMAGMA No. FP7-214107-2).
Dr. Antonio Correia Editor - Phantoms Foundation
INSPECTION OF GFRP COMPOSITES BY MICROWAVE NDEjmicro
Fiber reinforced polymer (FRP) composites form a major structural part ofaerospace and defence
applications. Non-destructive evaluation (NDE) plays an important role in assessing the quality and
health monitoring of FRP composite structures.Defect detection of FRPcomposite structures are by
different NDE techniques, such as ultrasonics, thermography, X-ray radiography. Depending on the type
of material, their characteristic features and accessibility of the test object etc. suitable techniquesare
employed. Microwave non-destructive evaluation (MWNDE) is an emerging NDE technique for
characterizing and inspecting dielectric structures. Microwave NDE finds application in the areas of
dielectric material characterization, determining thickness variation, defect detection and bond quality
inspection.Inspection of glass fiber reinforced polymer (GFRP) composites by near-field reflection
microwave NDE technique is presented in this paper. GFRP composite with known inserted defects such
as inclusion and flat bottom holes are inspected to understand and establish Microwave NDE. Results of
inspected structures by swept frequency reflection microwave NDE technique in the frequency range 8.2-
12.4GHz (X-band) and 12.4-18GHz (Ku-band) respectively are presented. The position of the reflection
characteristic curve indicates the depth of the defect in the inspected structure.
INSPECTION OF GFRP COMPOSITES BY MICROWAVE NDEjmicro
Fiber reinforced polymer (FRP) composites form a major structural part ofaerospace and defence
applications. Non-destructive evaluation (NDE) plays an important role in assessing the quality and
health monitoring of FRP composite structures.Defect detection of FRPcomposite structures are by
different NDE techniques, such as ultrasonics, thermography, X-ray radiography. Depending on the type
of material, their characteristic features and accessibility of the test object etc. suitable techniquesare
employed. Microwave non-destructive evaluation (MWNDE) is an emerging NDE technique for
characterizing and inspecting dielectric structures. Microwave NDE finds application in the areas of
dielectric material characterization, determining thickness variation, defect detection and bond quality
inspection.Inspection of glass fiber reinforced polymer (GFRP) composites by near-field reflection
microwave NDE technique is presented in this paper. GFRP composite with known inserted defects such
as inclusion and flat bottom holes are inspected to understand and establish Microwave NDE. Results of
inspected structures by swept frequency reflection microwave NDE technique in the frequency range 8.2-
12.4GHz (X-band) and 12.4-18GHz (Ku-band) respectively are presented. The position of the reflection
characteristic curve indicates the depth of the defect in the inspected structure.
INSPECTION OF GFRP COMPOSITES BY MICROWAVE NDEjmicro
Fiber reinforced polymer (FRP) composites form a major structural part ofaerospace and defence applications. Non-destructive evaluation (NDE) plays an important role in assessing the quality and health monitoring of FRP composite structures.Defect detection of FRPcomposite structures are by different NDE techniques, such as ultrasonics, thermography, X-ray radiography. Depending on the type of material, their characteristic features and accessibility of the test object etc. suitable techniquesare employed. Microwave non-destructive evaluation (MWNDE) is an emerging NDE technique for characterizing and inspecting dielectric structures. Microwave NDE finds application in the areas of dielectric material characterization, determining thickness variation, defect detection and bond quality inspection.Inspection of glass fiber reinforced polymer (GFRP) composites by near-field reflection microwave NDE technique is presented in this paper. GFRP composite with known inserted defects such as inclusion and flat bottom holes are inspected to understand and establish Microwave NDE. Results of inspected structures by swept frequency reflection microwave NDE technique in the frequency range 8.2- 12.4GHz (X-band) and 12.4-18GHz (Ku-band) respectively are presented. The position of the reflection characteristic curve indicates the depth of the defect in the inspected structure.
This document summarizes Paulo Sergio Fonseca's research project on growing and characterizing monolayer molybdenum disulfide (MoS2) using chemical vapor deposition (CVD). The goals were to grow monolayer MoS2 islands using CVD, characterize the material properties using techniques like photoluminescence spectroscopy and atomic force microscopy, fabricate devices on the MoS2 using electron beam lithography, and investigate the electrical properties through transport measurements. Key accomplishments included the successful growth and characterization of CVD monolayer MoS2, as well as fabricating a device to enable future transport studies of the material's electron mobility.
Time Domain Modelling of Optical Add-drop filter based on Microcavity Ring Re...iosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document summarizes the time domain modeling of an optical add-drop filter based on microcavity ring resonators. It uses the Multiresolution Time Domain (MRTD) technique to analyze the transmission characteristics of single and double ring configurations. The MRTD method provides high numerical accuracy while reducing computational burden compared to FDTD. The analysis investigates parameters like gap size, distance between rings, and ring/waveguide width to understand their effects on transmitted power and quality factors. Studies of a 3.4 μm diameter ring show quality factors of several thousand and a free spectral range of 9 THz can be achieved in the 1.55 μm wavelength range.
1. Le Van Hai is a postdoc researcher in Japan with experience in materials science, semiconductor processing, and device fabrication.
2. He has experience fabricating some of the world's smallest Fe-FET transistors and the first 64 kb Fe-NAND flash memory array.
3. He holds a PhD in applied physics from Osaka University where he worked on improving ferroelectric memory properties through surface treatments and developing a tunable photonic crystal filter using PLZT thin films.
This curriculum vitae outlines the educational and professional experiences of Dr. Felice Pignatiello. They include a Master's degree in laser spectroscopy, work developing laser systems for printing applications, and project management. Their roles have involved the development of laser technologies, including low power lasers for computer-to-plate applications and high power lasers. They have also conducted research on laser spectroscopy and optical sensing techniques. Currently, they work on optoelectronic projects for printing and collaborate on a project using UV illumination for medical applications.
The document discusses the use of optical fiber sensors for non-destructive testing applications. It notes that fiber optic sensors are well-suited for structural health monitoring due to their small size, light weight, and immunity to electromagnetic interference. The document outlines different types of fiber optic sensors and their advantages over conventional sensors. It also provides examples of how fiber optic sensors can be embedded in composite materials and structures to monitor factors like temperature, pressure, and strain for non-destructive testing.
Depth profiling and morphological characterization of AlN thin films deposite...Javier García Molleja
Authors: C. Macchi, J. Bürgi, J. García Molleja, S. Mariazzi, M. Piccoli, E. Bemporad, J. Feugeas, R.S. Brusa, A. Somoza.
The European Physical Journal - Applied Physics (2014) 67: 21301 (August 1st, 2014)
Only the first page is uploaded because EDP Sciences' copyrigth policy. Available at: http://dx.doi.org/10.1051/epjap/2014140191
Fiber optic sensors enable new mri applicationsSherry Huang
Fiber optic sensors have become a critical technology enabler behind the latest functional MRI (magnetic resonance imaging) suite upgrades and new MRI equipment designs.
Resonance frequency analysis of laser optical fiber based on microcantileverIJECEIAES
The normal frequency of smart beams was originated utilizing FEM [Ansys and Comsol] code for first five modes by varying the position of actuator from the fixed end of the structure, and it has a suitable arrangement with analytically found the standard frequency. This paper includes learning a resonance frequency analysis of laser optical fiber based on microcantilever of designing magnetic actuator using Ansys and Comsol simulation. The design of optical fiber includes Nickel cantilever, two magnets and one coil that apply to force on the cantilever. After the current flows in the coil domain, the shape of microcantilever will be deformed. It will move to z- direction that depends on the force direction. Two methods including, Comsol Multiphysics, Ansys and analytical equations have been utilized to calculate the resonance frequency, current and force values. The simulation results include calculating the current (magnetic current density) and effects of the magnetic field of the coil on the cantilever (force calculation). Utilizing this method is to limit faults(errors) of optical fiber laser between transmitter and receiver system (detection system) for any time of cutting coil when the signal of a laser passes through the coil. In conculsions, resonant frequency (f_n) tuning using cantilivier presented in the resrach have larger variable range by using simulations. However,the adjusting of the system and changing the deminsions.Resolutions to this problematic contain tuning the modes of resonant frequency to produce by cantilivier with 2-magnets and coil when the signal pass from laser source. Based on these simulations and characterization results, the proposed assembly can be a good applicant for evolving a low price, high material platform for many biological, laser optical fiber, communication, machine learning, biosensors and biomedical applications.
This document provides an annotated list of presentations, courses, seminars, and workshops by MJD and TETRAD related to topics like disaster management, biothreat detection, counterterrorism, and humanitarian applications of science and technology. It describes formal courses taught at universities, as well as presentations given at conferences on subjects such as border security, emergency response, and connecting dots to locate terrorist operations. The document aims to provide information for organizing future training opportunities on issues covered in the materials listed.
Coordinated And Unified Responses To Unpredictable And Widespread Biothreatsmartindudziak
Intelligent and rapid dissemination of information is essential for responding to CBRN threats but has been missing from most response plans. The CUBIT system provides a solution with its coordinated and unified approach. CUBIT uses sensors, analytics, diagnostics, treatments, and population control protocols incorporated as scalable and modular components that can dynamically interact. It employs principles of "plug and play" and adaptability to respond to unpredictable biothreats affecting populations when infrastructure is damaged.
1. The document discusses scanning probe microscopy (SPM) techniques such as atomic force microscopy (AFM) and their applications in biomedical research.
2. SPM allows high-resolution imaging of surfaces and can be used to study cell topology, structures like cytoskeletons and membranes, and how electromagnetic fields impact cells.
3. Experiments aim to use AFM to image living cells over time and study phenomena like solitons and fractals at the microscopic level to gain insights into cell behavior and pathology.
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Evolutionary IED Prevention 09 2006 Updated W Comments Jan2010martindudziak
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1. A FAMILY OF MICROINSTRUMENTS
FOR SMART MATERIALS, ENERGY MANAGEMENT,
AND BIOMEDICINE IN SPACE MISSIONS
1
M. Dudziak, PhD, Silicon Dominion Computing, Inc. (USA) and
Dept. of Physics, Moscow State University (Adjunct Faculty)
2
A. Chervonenkis, PhD, MODIS Corporation (USA)
ABSTRACT
Using a family of Fe-Ga based thin films fabricated epitaxially to have a range of magneto-optic
(Faraday effect) properties, we have designed a class of instruments that can be used for a variety
of challenging tasks pertaining to the maintenance and performance of spacecraft as well as
astronaut crews on long-term missions into deep space. The principle and the generic design of
this class of instruments applies to four diverse areas of utility and interest to the space
exploration community:
Smart surface sensing and non-destructive testing for spacecraft components, particularly
protective shield, hull, and structural assembly parts
Detection and mapping of electromagnetic field activity in and around the spacecraft,
including at substantial (> 10,000 km) distances, for use in safety management and also
possible novel energy production and propulsion techniques
Monitoring and mapping of biomagnetic fields detectable from human crew members as a
remote-sensing / multi-spectral technique in diagnostic and preventative medicine
High-speed spatial light modulators for optical signal processing and optical switching
including application to neural-network-like pattern processing.
Each device is based upon the operation of a MODE ™ sensor designed from the thin-film
material with its uniaxial anisotropic properties of magnetic domain transfer and reorganization in
response to external proximate magnetic fields of varying strength, intensity, and duration. The
sensor is coupled with a polarizing light source fed to the sensor via fiber optic channel, and a
spatial light modulator switching element that operates in response to the changes effected in the
sensor. The switching element provides input via fiber optic to an electro-optics element that is
interfaced with digital logic for activating a response based upon one or several of the output
configurations from the spatial light modulator.
1
CEO and Director of Research & Development, Silicon Dominion Computing, Inc., 3413 Hawthorne
Avenue, Richmond, VA 23222-1821, 804-329-8704, 804-329-1454 fax, mdudziak@silicond.com
2
Exec Vice President and Principal Scientist, MODIS Corporation, 1318 Pavilion Club Way, Reston, VA
20194, (703) 281-2100, (703) 281-2131 fax, arsen4@orc.ru
2. 1. INTRODUCTION
The goal of the MicroMAG project, conducted as a joint venture of Silicon Dominion
Computing, Inc. and MODIS Corporation, has been to develop a highly compact and modular set
of devices for magnetic imaging and control functions based upon Faraday-effect magneto-optics,
using a proprietary class of thin-film sensors with extremely sensitive (< 10-7 Oe) properties.
The initial phase of the project has been to refine the sensor materials and to design a class of
instrumentation that will meet the requirements of several functions for aerospace-based
applications that benefit from magneto-optic methods in non-destructive defect detection and
other EMF intensity measurements for structural, engineering, and bioengineering applications.
Modularity, lightweight composition, compactness, and robustness for unmanned or low-
maintenance applications have been goals of the project in order to provide for systems that are
consistent with earth-orbit and deep space missions.
Surface fatigue, stress, crack, and other defect testing operations can be performed by introducing
an array of sensor apparatus throughout the spacecraft structure, or by a member of the crew (or a
robot) using a portable inspection unit. Generation of a “flash” eddy current in the metal
structure is required but can be effected by either a built-in or portable apparatus including
permanent magnet units that can be incorporated into the sensor device.
EMF activity can be observed and measured through modification of the MODE sensor thin film
for increasing sensitivity at some cost in field effect intensity or duration (memory) within the
sensor. The possible applications of this technology for energy generation have been discussed in
a previous paper, “ Design of Magneto-Optic Wide-
Area Arrays for Deep Space EMF Studies and Power System Control”[Dudziak, 1998a].
For biomedical applications, the principle is similar to that which would be employed in detection
of EMF outside the ship or in deep space. The instrumentation is intended principally for
external measurements, using a band-aid strip device that can be taped to different locations on
the body, with fiber-optic links to and from the sensor.
Spatial light modulators (SLM) for optical switching and image processing have been designed
using magneto-optic media with typical switching times of 1 µs but with recent new methods it is
possible to attain reduction in size and increase of speed to approx. 0.1 µs and optical contrast
exceeding 1000:1. Such characteristics enable SLMs to be considered as a competitive solution
for massively parallel or widely-dispersed network applications onboard spacecraft including
embedded devices in smart structural materials.
3. All of these applications involve a fundamental common technology, using Fe-Ga based
magneto-optically sensitive thin films of variable composition and sensitivity, and known as
MODE ™ (Magneto-Optic Detection and Encoding).
2. MODE™ THIN-FILM AND ITS PROPERTIES
The MODE ™ technology is based upon a field visualizing film (FVF). It consists of a
transparent ferromagnetic layer of Bi-substituted iron-garnet grown by LPE technique on a non-
magnetic substrate. The composition of the FVF is characterized by the formula (R Bi)3 (M
Fe)5012, where R is a rare-earth ion (Y, Lu, Tm, Gd, Ho, Dy, Tb, Eu for example) and M is
generally Ga or Al. Magnetic and magneto-optic properties of the FVF are controlled by
composition, growth conditions and post-epitaxial treatment [Randoshin, 1990]. The specific
Faraday rotation of 10^4 deg/sm and absorption coefficient less then 10^3 cm-1 are available in a
generic composition (Tm Bi)3 (Fe Ga)5012. High contrast domain structures can be easily
observed using a polarizing microscope. Figures 1 and 2 illustrate four sample images obtained
with the MODE ™ technology, all laboratory images made in ambient environments using
sample materials (microprocessor chip circuitry (pads) and steel plates with defects) such as may
be encountered on space vehicles and satellite assemblies.
Figure 1 MODE imaging of 16-bit microprocessor lead pads
4. Figure 2 Digital imaging of steel plate by MODE (left) and
ordinary light (right)
The magneto-optic layer or FVF is created by growing the epitaxial layer on the garnet substrate,
deposited in a supercooled flux, containing a solvent of composition Bi203-PbO-B203 as well as
garnet-formed oxides at a temperature range of 940K to 1108K. By introducing a high level of
Bi3+ ion substitution into the FVF a high MO figure of merit can be achieved, s.t. Ψ= 2ΘF / α >
10 grad/dB. An important feature of the FVF of value for possible deep space magnetic anomaly
and variation studies is the high domain wall velocity (> 1000m/s) obtained in four types of films:
(i) high-anisotropic-oriented films with Y and Lu composition, in the presence only of in-plane
magnetic fields, (ii) films with Gd and Tm, with angular momentum compensation (AMC), (iii)
films with Y, Lu, and Pr (orthorhombical magnetic anisotropy (ORMA), and (iv) films with Gd
and Eu (both AMC and ORMA).
Figure 3 illustrates saturation magnetization properties of the MODE film [B(G)] and an iron
platelet [B(Fe)] - the ratio of the anisotropy field H / B(G) increases over the normal distance z.
5. Figure 3 MODE Saturation Magnetization Levels
Figure 4 provides a schematic of the basic operation of magneto-optic imaging using a MODE ™
thin film crystal sensor. By incorporating the polarized light source into a fiberoptic delivery
system, the packaging of a sensor unit can be sized down to a chip set incorporating CCD and
control logic in one device and optics in a second hybrid device.
Figure 4 Basic operation of MODE Imaging
3. MagVision PROTOTYPE SCANNER
An early laboratory workbench scanner has been produced which generates NTSC or PAL
compatible video output from a magneto-optic imaging apparatus. The basic design is illustrated
in Figure 5 below. The “rotatable analyzer” is replaceable with a micro videocam assembly and
can be adapted with an objective lens for a microscope. The solid housing can be a permanent
magnet of varying strength (typically 5G) for enhancing the magnetic field of the sample as in
6. imaging applications where the magnetic field of interest is affixed to a nonmagnetizable surface
such as plastic or some insulator. The minimal detection of the current scanner is @ 0.1 Oe but
the theoretical limit of the thin film extends to 10 -8 Oe. A yellow-orange halogen lamp is used
with a thin-film polarizer for the light source.
Figure 5 Schematic of MagVision Prototype Scanner
4. MODE ™ DEFECT AND STRESS DETECTION
The MODE ™ technology has been tested in several experiments for use in detecting microcracks
and other defects in metallic surfaces. These tests have been performed using a variety of
materials, both magnetized and non-magnetized but ferromagnetic. The objective has been to
refine methods for magnetic imaging that can be implemented without the use of an external eddy
current applied to the sample, either as a steady low-amp current or using a “flash” technique
(approx. 10-15 kA for 10-20 ms).
Real-time images of defects are obtained in both magnetic and nonmagnetic metal parts as well as
in magnetic ceramics (ferrites) [Randoshin, 1990]. Magnetic anomalies caused by these defects
are sensed by the MODE ™ device. In ferromagnetic metals such as steel, the instrument senses
and displays an image of the flux image leakage associated with the flaw in a previously
magnetized test piece, while in nonferromagnetic metals, particularly in the case of Al, the
instrument excites in the test piece eddy currents in order to provide a direct image of defects
resulting from the magnetic fields with the flow of eddy currents.
The whole FVF region spontaneously divides into a labyrinthine domain space (DS), the
magnetization vector M being strictly normal to the FVF surface. Domain walls (DWs) are taken
to be infinitely thin and thus M direction changes sharply to the opposing vector coming across
the DW. The DS varies due to DW displacement when field H o normal to FVF plane is applied.
If M in the domain and H o directions coincide, the domain increases in size; otherwise it
decreases and inevitably collapses at the saturation field H s. The primary FVF parameters (i.e.
uniaxial anisotropy constant Ku, saturation magnetization M s, coercive field Hc and thickness h)
characterizing the DS behavior under the influence of inhomogeneous field, are customized
7. through the composition process to satisfy the specific requirements. If a purely uniaxial
anisotropy and zero Hc could ever be reached, the DS would be in unique conformity with the
external field. It is extremely important that the FVF possess a very high uniaxial anisotropy
field Hk=2Ku/Ms At a fixed Ms the desired Hk > 103 kA/m is attained by increasing Bi content. If
the constants of non-uniaxial anisotropy and K u are of same order then in the presence of some
invariable inhomogeneous field the DS patterns would differ when rotating the film in its plane.
The requirements on the quality of the MODE ™ FVF coincide with those for classical bubble
memory devices. It is essential that the FVF possess a very low concentration of magnetic defects
(i.e. single dislocations, inclusions, scratches) which impede a DW movement. All magnetic
parameters and thickness are to be held constant to 1% over FVF region. Under such conditions
homogeneously distributed coercivity always exist. Taking this into account, if the MODE defect
detection sensor should possess "memory" capability, than it is necessary to induce elevated and
uniform Hc of the order of Ms. There are several technological methods to increase H c either
during the epitaxial process or by special post-epitaxial treatment of the film.
4.1 Defect Detection Operating Principles
A magnetically soft object is magnetized up to saturation in its plane by an external field, created
for example by a pair of permanent magnets such as are affixed to the sensing device. MODE ™
film (FVF) grown on a transparent substrate is brought into contact with the object surface. If
within the object thickness under the MO film a defect is present, the magnetic flux formed by
the permanent magnets will be distorted in such a way that a portion of the flux force lines will
emerge from the object surface and penetrate into the sensitive element, thereby rearranging its
equilibrium domain structure. The changes in the DS may be visualized by the help of Faraday
effect. The light from a polarized light-source by the help of a light-dividing cube is directed on
the MODE ™ film, which is closely attached to the object surface. Passing twice through the
sensing film (due to reflection from a mirror layer) the light after the objective comes onto the
screen where the contrast image of the domain structure is formed.
In the absence of the defect a uniform ("gray") DS will be seen on the screen. This refers to the
demagnetized state of the film. However in the presence of the defect the DS in the film will be
distorted under the influence of the magnetic flux force lines going out of the object surface.
These distortions will be seen on the screen and thereby identify the position of the defect.
Computer modeling in agreement with the experiment has shown, that the visualized picture of
the defect substantially depends on the defect dimensions and the deepness of its position.
When the inspection subject is a nonmagnetic metal the principle scheme of the detector is
similar to the fore-mentioned (see for example [Fitzpatrick, 1993]) with the exception that
excitation of stray magnetic fields by means of eddy currents are additionally introduced. Both
sinusoidal and pulse power sources may be used. The excitation of high magnetic fields by high
power unique current pulses has significant advantage over traditional excitation by high
frequency eddy currents/ In the former case, due to thermal limitations, high values of currents
are prohibited, hence the induced magnetic fields are small. As a result the sensitivity and spatial
resolution of the sensor is limited. The use of unique current pulses eliminates these limitations,
however, due to the short duration of the pulses (several ms), and dictates the introduction of
MODE ™ pattern "memory" capability.
Two mechanisms are proposed for MicroMAG implementation. In one case the sensitive MO
element is produced with artificially induced and elevated DW coercivity. This provides image-
8. memory of the rearranged DS by the element. In the second case one uses an intermediate
flexible magnetic carrier (a kind of magnetic tape) that “remembers” or “captures” the structure
of the stray magnetic field above the object surface in the case of close attachment of the tape to
the object surface. After that step the visualization of the formed magnetic pattern is conducted
by the use of a standard sensitive MODE ™ detecting element. The second mechanism provides
an additional advantage connected with the opportunity to reveal hidden defects in the objects
with nonflat surface (welds, tubes etc.) since, unlike the fixed-element sensor unit (cf. Figure 5),
magnetic resin tape can easily replicate the surface of any arbitrary object.
4.2 Summary of Advantages
MODE ™ defect detection has a number of advantages over existing eddy-current instruments
and techniques. The system is capable of providing direct, real time images of cracks, corrosion
and other anomalies in inspected areas, as well as high resolution, with low probabilities of false
calls (indicating a defect when none is present). Direct visual images, which can be directly
recorded on video-tape for complete documentation of an examination, are intuitively
understandable and easy to interpret and require no preprocessing. In contrast, interpretation of
the impedance plane displays typically provided by eddy-current instruments are often difficult to
stabilize and tune and require a highly-trained operator. The MODE ™ approach lends itself to
operation by the non-NDT-specialist and to automated expert-system enhanced operation.
Figures 6 through 9 below illustrate several representative images.
Figure 6 MODE
picture of
nonmagnetic
inclusion (round
spot) in a platelet
of conventional
stainless steel.
The black area to
the right is the
edge of the
platelet.
9. Figure 7 MODE
picture of an
internal microcrack
in a conventional
steel alloy
platelet. The
depth and
dimensions of the
crack may be
evaluatable through
translation of the
Figure 8 MODE image
(left) of steel
platelet0.8mm thick
(upper surface)
with defects on
lower surface
ranging from 0.1mm
to 0.2mm deep
(shown in optical
image (right)
Figure 9 (Upper)
Optical-only image
of a steel blade
covered by a thin
(0.5 – 2 mm) layer
of ice. (Lower)
MODE image showing
transverse crack in
the steel and
visible through the
ice.
10. 5. MODE™ APPLIED TO EMF DETECTION THROUGH NONMAGNETIC,
NONCONDUCTIVE SURFACES
Early tests with MODE ™ thin-films using the laboratory sensor device illustrated in Figure 5
have been performed with a number of materials including paper and plastic. Figure 10 below
illustrates some of the results. Imaging is performed with the assistance of a peripheral
permanent magnet, a hexaferrite composition (BaFe 12O19), measuring 20 x 15 x 7mm, with 6000
G magnetic saturation and uniaxial anisotropy normal to the flat sample surface.
Figure 10 (Left) Image (10X) of magnetic code layered on plastic;
(Right) Image (10X) of magnetic ink printed onto paper
There are several possibilities for how MODE ™ can be employed in spacecraft operations
through the detection of EMF and for the measurement of anomalies that may be the result of
ferromagnetic artifacts or inclusions within asteroids, planets, and other natural bodies
encountered in space. While much of the following is hypothetical and speculative, it is based
upon experiments indicating that the sensitivity of the MODE ™ films can serve a wider purpose
than the traditional non-destructive testing and evaluation for metallic components which itself
can be useful for spacecraft and other man-made devices.
An array of sensors equipped with fiber optic light sources and return channels could be
distributed throughout critical parts, sections, and components of a spacecraft, or in a deployed
external array, for detection of changes in magnetic fields. Such field variations might be
indicate systemic flaws within portions of the spacecraft structure, particularly in regions of a
craft that may be powered by ionic or other nuclear-reaction based propulsion. Alternatively such
EMF fluxes might serve as predictable behaviors, a type of EMF barometer, indicative of
changing conditions in the external environment, much as the MODE ™ sensor has been applied
to measurement of EMF leakage from high-voltage power lines. The deployment of such an
external array could be extended for literally millions of kilometers provided that there were
minimal-energy triggered transmitters that could in turn relay useful data upon detection to a
receiving array, either on a spacecraft or in an intermediate location such as a geo(planet)-
stationary orbital platform.
The possibility that such a wide-area array could be applied to novel “breakthrough physics”
propulsion systems such as the extraction of useful energy from coherent vacuum currents has
been explored in [Dudziak, 1998b]. It would necessitate a similar type of simple, small, and
11. fault-tolerant (through parallelism) device such as would play a role in the non-destructive testing
and evaluation applications, leading to the MicroMAG architecture (cf. Section 8.)
6. MODE™ APPLIED TO BIOENGINEERING
A third application for MODE ™ is in the measurement of biomagnetic fields that may be emitted
either naturally by the human body or induced artificially through the introduction of magnetic
tags into pharmaceutical agents. The latter approach has been investigated by Davis et al
[Wagreich, 1996a; Wagreich, 1996b] using Mach-Zehnder and Fabry-Perot interferometers with
promising results. It is possible that the increased sensitivity of the MODE films can accomplish
in a smaller and simpler instrumentation the same level of accuracy (low pT/Hz 1/2) over several
cubic cm or more in spatial resolution.
Figure 11 shows the results of very preliminary studies using the MODE sensor to reproduce the
magnetic field structure above test samples of thin film permanent magnets (1 cm in diameter and
100 micron thick). The top row has images made with the thin film directly on the surface, the
lower row with the sensor positioned 0.5 mm higher. There are different levels of bias field and
clearly visible asymmetry caused by imperfect technology of SmCo 5 sputtering.
Figure 11 MODE imaging of permanent magnet thin films
By reducing the size of the MODE sensor element it is possible that an array of such sensors can
be positioned in a configuration that is analogous to an array of EEG or MEG sensors.
Experiments are underway to develop an improved technique of affixing the thin film element to
flexible materials which include embedded optical fibers woven into the fabric. In such manner a
multitude of geometries can be handled for measurement tasks, with the optical outputs from the
sensor array feeding into a spatial light modular device (SLM) as described briefly in the next
section.
12. 7. MODE™ SPATIAL LIGHT MODULATORS
A fourth projected use for a modular microscale class of MODE elements is for spatial filtering
and optical correlation and switching that can be employed not only in fast binary image
comparison and recognition but in other pattern recognition and matching tasks. Such processing
may not be derived from images per se but can originate with data sets that are measured and
stored as optical patterns. Applications in space of this nature could include measurement of
vibration data, for instance, where similar to atomic force microscopy principles, laser beam
reflections are routed to a photodiode array. The foremost use may be in optical computing
where operations such as Fourier and Gabor transforms could be rapidly executed through a
MOSLM (magneto-optic spatial light modulator).
What makes it possible to have a practical and small scale SLM is the typical switching time of ~
0.1 µs while at the same time attaining optical contrast exceeding 1000:1 and optical efficiency of
0.15 at λ = 0.63 µm, with a specific Faraday rotation at that λ of Θρ = 2.0 ± 0.1° / µm with optical
absorption coefficient of α=0.35 – 0.4 dB/µm. These properties apply to (Rbi) 3(FeGa)5O12 films
grown on (GdCa)3(ZrMgGa)5O12 substrate with crystalline lattice parameter of a=12.495 Α. In
the diffusion heat process, employing an Si mask allows the formation of a domain structure that
can have considerable variation in geometry and the areas of decreased magnetization and single
domain structures provide for light shutters with typical cell structure @ 100 µm2.
By switching from a (111) orientation to an in-plane field the domain wall velocity V s can be
increased to @ 1000 m/s and particularly by composition with high g-factor and high
orthorhombic anisotropy to @ 3000 m/s as an upper limit. At V s = 3000 m/s and with MOSLM
dimensions of 100 µm2 the switching time is approx. 0.03 µs.
An experimental platform for a high-speed optical correlator based upon the MODE thin film was
developed and is described in [Chervonenkis, 1992]. This was a large scale laboratory device
using two MOSLMs in series separated by a polarizer and Fourier processing element. Test
images consisted of 16 x 16 elements and comparisons were made between input and control
images in order to filter out the differences between patterns.
Reduction of the MOSLM could be attained to a degree limited by the construction of the Si
mask and the limits of domain wall distinguishability. Reducing the cell structure size is a topic
of current research. The proposed approach is to create the cells in the form of pits or
indentations in the background on the initial film thickness such that the thickness within the pit
does not exceed 1 µm. Single-domain states for each cell can be maintained even in high
saturation magnetization (e.g., @ 300 G). Ion implantation can create a uniaxial anisotropic
gradient that is normal to the plane of the film and thereby the remagnetization for cell switching
occurs not as a result of vertical domain wall propagation inwards from the edges to the centers of
the cells but instead by vertical propagation of the horizontal domain walls themselves. even at a
lower Vs = 1000 m/s the switching time can be estimated at 1 ns maximum. The object for doing
so is to reduce not only the performance time for such a MOSLM but to enable, once again, the
deployment of a potentially massive and distributed number of simple and small sensing arrays
across arbitrarily large surfaces such as for smart materials applications.
13. 8. MicroMAG MODULAR ARCHITECTURE: FUTURE DIRECTIONS
A truly microscalar MicroMAG device has not yet been constructed, only simulated through
larger apparatus with the theoretical limits and constraints of the MODE thin film providing the
supporting evidence that the scale can be miniaturized. Scale however is not the only issue
governing the utility of this technology for the multiple applications indicated above. For near-
term space applications most technical implementation will effectively rest upon fabrication
performed on Earth or in limited geo-stationary or lunar bases. Developing an apparatus that can
be easily reproduced and introduced into a number of different structures will be a step forward
from having very complex and unique instrumentation that cannot be interchangeable. The
MicroMAG project aims at creating the equivalent of the simple diode or transistor in terms of
functional simplicity and ubiquity. The goal is a basic magneto-optic component that can be
incorporated into a variety of “circuits” so to speak just like a simple capacitor or resistor can be
used in a variety of tasks and in a variety of physical configurations.
One area of current attention by the MODIS research team is on the development of a common
interface for optic channel devices to MODE sensors that may require variable lines for input and
output depending upon the nature of how many individual sensors are employed. This is the
equivalent of designing a crossbar switch to serve a variable number of line-in and line-out
signals and where the actual switching element can be replaced depending upon the task. In this
way a common hardware component can be designed which will enhance the production and
fabrication of optical processing networks such as MONA (magneto-optic neural array), an
extension of earlier work by one of the authors and others at using MOSLM technology for
neural-like distorted image recognition and correction [Nikerov, 1991].
This MODE element may never be reducible to the nanoscale level due to the constraints of
domain size and domain wall behavior. However, some type of nanostructured material,
embedded with ferromagnetic atoms in a prescribed geometry, perhaps through a controlled
AFM nanofabrication process, could give be employed to enhance sensitivity to a MODE sensor
embedded within or placed on the immediate surface of the material. The closest analogy seems
to be that of the use of magnetic ink or fibers within paper or plastic (cf. Figure 10 above). The
nonmagnetized, non-conductive material, perhaps part of the structure of a spacecraft or the
protective suit of an astronaut, would be difficult to test for cracks, leaks, and other micro-
damage. Embedding a very thin and distributed layering of ferromagnetic atoms, either through a
physical spray process or as fibers, could enable a MODE apparatus to sense breaks indicative of
the embedding material failure. What might be detected are breaks like those irregularities in
Figure 10 (right) or Figure 11.
No doubt structural testing and integrity measurement is the dominant and leading application of
MODE technology in space. SLM-based computing and biomedical applications, much less deep
space energy extraction, are quite futuristic and hypothetical. However it seems to be sensible to
start from the outset to address both that which is known and predictable and that which is
hypothetical so that what emerges is something that can hopefully serve both should the
hypothetical, as remote as it may seem today, turn out to be quite concrete and definite. Space
travel and colonization itself seemed to be relegated by many to the domain of Jules Verne until
some four decades ago, and despite the hopefully brief hiatus in major space-based undertakings,
the next decade or two may yield more surprises and changes of thought than those brought on by
the likes of Gagarin and Glenn.
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