Since the Middle Ages, Fibonacci (FB) numbers have attracted the interest of many scientists. In the recent years, a great research effort has been spent on the applications of FB numbers and sequences. It has been demonstrated that also... more
Since the Middle Ages, Fibonacci (FB) numbers have attracted the interest of many scientists. In the recent years, a great research effort has been spent on the applications of FB numbers and sequences. It has been demonstrated that also some properties of resonant electronic systems are related to FB numbers. In this paper, an optical resonant device, with resonant frequencies spaced according to the FB series, is proposed, demonstrating the analogy with coupled electrical resonant cells. The proposed device consists of a silicon-based photonic coupled ring resonators, properly designed such that the resonant frequencies correspond to the sequence: 0.618·ω0,…, ω0, …, 1.618·ω0, where ω0 is the operating angular frequency [rad/s]. These features make the device suitable for several applications, e.g. frequency-based quantum cryptography for the transmission of quantum information.
Trapping and manipulation of matter at micrometer scaled up to a single nanoparticle has assumed a fundamental role for several applications and, particularly, in biomedical environments. Furthermore, trapping of living matter at the... more
Trapping and manipulation of matter at micrometer scaled up to a single nanoparticle has assumed a fundamental role for several applications and, particularly, in biomedical environments. Furthermore, trapping of living matter at the nanoscale, such as proteins and DNA sections, allows the study of many diseases and also the investigation of the effects of new drugs on a single pathogen like a virus.
According to the World Health Organization forecasts, AntiMicrobial Resistance (AMR) is expected to become one of the leading causes of death worldwide in the following decades. The rising danger of AMR is caused by the overuse of... more
According to the World Health Organization forecasts, AntiMicrobial Resistance (AMR) is expected to become one of the leading causes of death worldwide in the following decades. The rising danger of AMR is caused by the overuse of antibiotics, which are becoming ineffective against many pathogens, particularly in the presence of bacterial biofilms. In this context, non-destructive label-free techniques for the real-time study of the biofilm generation and maturation, together with the analysis of the efficiency of antibiotics, are in high demand. Here, we propose the design of a novel optoelectronic device based on a dual array of interdigitated micro- and nanoelectrodes in parallel, aiming at monitoring the bacterial biofilm evolution by using optical and electrical measurements. The optical response given by the nanostructure, based on the Guided Mode Resonance effect with a Q-factor of about 400 and normalized resonance amplitude of about 0.8, allows high spatial resolution for t...
Research Interests: Biosensors and BioSensors
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The conceptual scheme of an LiNbO3 integrated optical circuit for onboard data processing is proposed. The design of each integrated component and its fabrication techniques are discussed. Finally, a simulation of the whole circuit... more
The conceptual scheme of an LiNbO3 integrated optical circuit for onboard data processing is proposed. The design of each integrated component and its fabrication techniques are discussed. Finally, a simulation of the whole circuit performance is presented.
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ABSTRACT GaAs etching process has been studied in Ar–Cl 2 rf discharges at 200 mTorr as a function of gas composition, substrate temperature, and bias voltage. Actinometric optical emission spectroscopy has been utilized for gas phase... more
ABSTRACT GaAs etching process has been studied in Ar–Cl 2 rf discharges at 200 mTorr as a function of gas composition, substrate temperature, and bias voltage. Actinometric optical emission spectroscopy has been utilized for gas phase diagnostic. Surface analysis has been carried out by x‐ray photoelectron spectroscopy and scanning electron microscopy. Anomalies found in the etching regimes have been interpreted as caused by the presence of an inhibiting oxide–chloride film and by the desorption of chlorine adsorbed on the surface by low‐energy bombarding ions.
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ABSTRACT In this paper some significant aspects of the possible and useful synergies in R&D programs and the main problems in the technology transfer process relevant to space and leading to competitiveness are presented.... more
ABSTRACT In this paper some significant aspects of the possible and useful synergies in R&D programs and the main problems in the technology transfer process relevant to space and leading to competitiveness are presented. Guided-wave devices and recent technological advances in optoelectronics for space are also described and discussed to highlight new directions towards innovation.
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ABSTRACT In this work, a generalized model of acoustooptic multifrequency interaction in wave-guiding structures is described. The model, which is based on the generalized coupled model theory, can evaluate the diffraction efficiency in... more
ABSTRACT In this work, a generalized model of acoustooptic multifrequency interaction in wave-guiding structures is described. The model, which is based on the generalized coupled model theory, can evaluate the diffraction efficiency in Bragg regime when a multifrequency signal is applied to the interdigitated transducer deposited on the optical waveguide surface. The influence of fabrication parameters of Ti:LiNbO3 waveguides on the diffraction efficiency and on the linear dynamic range of acoustooptic multifrequency Bragg cells has been also considered under monomodal propagation condition. Our results assert that the best performance in terms of linear dynamic range can be obtained on Ti:LiNbO3 waveguides having weak refractive index change and small initial titanium thickness in the medium radiofrequency range. A qualitative comparison has been performed with results obtained by other authors in the case of collinear acoustooptic interaction.
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Angular Response of Narrow Band 2D-PBG Guided Wave Filters. [AIP Conference Proceedings 709, 439 (2004)]. Caterina Ciminelli, Francesco Peluso, Vittorio MN Passaro, Mario N. Armenise. Abstract. A very compact narrow ...
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ABSTRACT Miniaturization of the currently available medium- and high-performance angular velocity sensors is crucial for aerospace and defense industry. To face this technological challenge, we are investigating a new gyro, called... more
ABSTRACT Miniaturization of the currently available medium- and high-performance angular velocity sensors is crucial for aerospace and defense industry. To face this technological challenge, we are investigating a new gyro, called gyroscope-on-chip (GoC), based on the InP photonic integrated circuits technology. The sensor we refer includes a passive ring resonator with a Q greater than one million and several optical/optoelectronic components all monolithically integrated on a single InP chip. Recent progress on the demonstration of the GoC is reported in this paper. In particular, the configuration of the readout circuit and the countermeasures against the backscattering noise are discussed.
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ABSTRACT This presentation gives new results on single-mode planar and stripe waveguides on both lithium tantalate and lithium niobate formed by proton-exchange. The largest Δneff obtained on lithium tantalate are 0.0174 on x-cut and... more
ABSTRACT This presentation gives new results on single-mode planar and stripe waveguides on both lithium tantalate and lithium niobate formed by proton-exchange. The largest Δneff obtained on lithium tantalate are 0.0174 on x-cut and 0.0033 on z-cut respectively. Results on in-plane scattering, insertion loss and of microanalysis will be reported.
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Production of high- performance and low-cost new devices to be used in space applications is strongly required due to the remarkable development of innovative technologies in the last few years. Guided-wave optoelectronics technologies,... more
Production of high- performance and low-cost new devices to be used in space applications is strongly required due to the remarkable development of innovative technologies in the last few years. Guided-wave optoelectronics technologies, including integrated optics, acousto-optics and electro-optics can provide some significant benefits to the space applications. In particular, they can overcome the intrinsic limits of the conventional technologies
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ABSTRACT A numerical method based on Floquet-Bloch formalism has been used in this paper to investigate the properties and design criteria of 1D multi-quantum-well (MQW) guided-wave planar photonic bandgap (PBG) structures. The approach... more
ABSTRACT A numerical method based on Floquet-Bloch formalism has been used in this paper to investigate the properties and design criteria of 1D multi-quantum-well (MQW) guided-wave planar photonic bandgap (PBG) structures. The approach allows a clear understanding of all the involved physical effects without making any restrictive assumption. 1D guided-wave PBGs including MQW can be used for microresonators and nonlinear tunable filters.
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ABSTRACT In the last few years, the resonant micro-optical gyroscope (RMOG) is gaining an increasing interest especially due to its features in terms of size, mass, power consumption, and cost. In this context, we are working on the... more
ABSTRACT In the last few years, the resonant micro-optical gyroscope (RMOG) is gaining an increasing interest especially due to its features in terms of size, mass, power consumption, and cost. In this context, we are working on the demonstration of the first InP photonic gyroscope-on-chip based on the RMOG configuration. In this paper some recent advances are reported, with specific emphasis on the readout optoelectronic circuit and the preliminary results of the system test. Backscattering noise mitigation through the carrier suppression is discussed on the basis of experimental results.
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ABSTRACT In this paper the design of a novel guided-wave correlator for air-bone synthetic aperture radar (SAR) data processing is illustrated. Correlation in azimuth direction is carried out through an optical transmission mask which... more
ABSTRACT In this paper the design of a novel guided-wave correlator for air-bone synthetic aperture radar (SAR) data processing is illustrated. Correlation in azimuth direction is carried out through an optical transmission mask which includes the azimuth reference signal, and a two-dimensional CCD array working in time delay integration mode. The guided-wave correlator proposed in this paper performs the correlation in ground range direction operating in time integration mode. The device utilizes an optical waveguide formed in z-cut LiNb03 by proton exchange in dilute benzoic acid. The waveguide supports a collimation lens, a surface acoustic wave Bragg deflector and a grating filter which allows to remove the undiffracted beam. This new filtering technique does not require fabrication of lenses performing spatial Fourier transform. Moreover, usual procedures of planar technology can be followed to fabricate the correlator. When a laser beam at X = 0.84 pm is intensity modulated by the reference chirp signal having a bandwidth of 50 MHz, a correlation signal referred to the reference signal carrier is obtained. In this way the separation of the real and imaginary parts of the output signal can be carried out leading to an easy digital post-processing. Small size, light weight and low power consumption are further advatanges of the new correlator. Finally, a range swath of 1 Km with a resolution cell of 3m x 3m is easily achieved for an air-bone SAR data processor.
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ABSTRACT Deep investigation on potential polymeric materials, lattice periodicity, and residual layer in the waveguide core has been carried out to optimize the design of a 2-D polymer photonic band gap filter for telecommunication systems.
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ABSTRACT A high Q/V mid-infrared 1D photonic crystal cavity in chalcogenide glass AMTIR-1 (Ge33As12Se55) resonating at λR=5.26 μm has been proposed as a key element of a sensor able to evaluate the nitric oxide (NO) concentration in the... more
ABSTRACT A high Q/V mid-infrared 1D photonic crystal cavity in chalcogenide glass AMTIR-1 (Ge33As12Se55) resonating at λR=5.26 μm has been proposed as a key element of a sensor able to evaluate the nitric oxide (NO) concentration in the exhaled breath, namely fraction exhaled NO. The cavity design has been carried out through 3D finite-element method simulations. A Q-factor of 1.1×104 and a mode volume V=0.8 (λ/n)3, corresponding to a Q/V ratio of 1.4×104(λ/n)−3, have been obtained with a resonance transmission coefficient T=15%. A sensitivity of 10 ppb has been calculated with reference to the photothermal physical property of the material. Such a result is lower than the state-of-the-art of NO sensors proposed in literature, where hundreds of parts per trillion-level detection seem to have been achieved, but comparable with the performance obtained by commercial devices. The main advantages of the new device are in terms of footprint (=150 μm2), smaller at least 1 order of magnitude than those in literature, fast response time (only few seconds), and potential low cost. Such properties make possible in a handheld device the sensor integration in a multi-analysis system for detecting the presence of several trace gases, improving prevention, and reducing the duration of drug treatment for asthma and viral infections.
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ABSTRACT We present a novel configuration of photonic/plasmonic microcavity with a 1D photonic crystal cavity (PhC) vertically coupled to a metal slot. A strong light-matter interaction is allowed, due to a strong photons confinement in... more
ABSTRACT We present a novel configuration of photonic/plasmonic microcavity with a 1D photonic crystal cavity (PhC) vertically coupled to a metal slot. A strong light-matter interaction is allowed, due to a strong photons confinement in the metal slot, which corresponds to a low mode volume (V = 2×10-3 (λ/n)3). A Q-factor of 2.6×103 has been obtained, providing a ultra-high Q/V = 1.3×106 (λ/n)-3, with a resonance transmission of 48 % λ = 1563.70 nm. Accurate 3D Finite Element Method (FEM) simulations have been performed to design the cavity. Optical trapping has been identified as the most suitable application for the proposed device, due to a strong gradient of the light field in the metal slot that allows high values of optical force and, consequently, the ability to trap nanoparticle with a diameter less than 100 nm.
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In this paper the performances of photonic interconnection networks are related to the characteristics of the switching elements. In order to design a photonic interconnection network the architecture has to be chosen on the basis of some... more
In this paper the performances of photonic interconnection networks are related to the characteristics of the switching elements. In order to design a photonic interconnection network the architecture has to be chosen on the basis of some topological and fault-tolerance characteristics. ...
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In this paper report on the design of a 2D PBG filter in polymeric material. The filter is a Fabry-Perot cavity having a self-sustained membrane configuration. A deep parametric analysis has been carried out for improving the performance,... more
In this paper report on the design of a 2D PBG filter in polymeric material. The filter is a Fabry-Perot cavity having a self-sustained membrane configuration. A deep parametric analysis has been carried out for improving the performance, taking also into account the fabrication tolerances Best performance in terms of lateral confinement have been obtained in case of square lattice. As for materials, polystyrene shown best in terms of refractive index value, length of the photonic crystal structure and attenuation value in the band gap. The filter can be used either in sensing applications or in telecommunication field.
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Commercial success of the He–Ne Ring Laser Gyroscope (RLG) began in the late 1980s and early 1990s. Since He–Ne RLG first demonstration in 1963 (Macek and Davis, Appl Phys Lett 2:67–68, 1963 [1]), a number of industrial companies have... more
Commercial success of the He–Ne Ring Laser Gyroscope (RLG) began in the late 1980s and early 1990s. Since He–Ne RLG first demonstration in 1963 (Macek and Davis, Appl Phys Lett 2:67–68, 1963 [1]), a number of industrial companies have developed a great research effort for RLG technology improvement so that this optical sensor has become a widely diffused commercial device. For instance, navigation systems based on He–Ne RLGs has been installed on over 50 different aircrafts (Barbour, AiAA Guidance, Navigation and Control Conference, Montreal, Canada, 2001 [2]). Since several years, He–Ne RLG dominates the high-performance gyros market.
ABSTRACT In this work the modeling of non collinear acoustooptic multifrequency interaction in wave- guiding structures is presented. The new model, which is based on the generalized coupled mode theory, allows us to evaluate the... more
ABSTRACT In this work the modeling of non collinear acoustooptic multifrequency interaction in wave- guiding structures is presented. The new model, which is based on the generalized coupled mode theory, allows us to evaluate the diffraction efficiency in Bragg regime when a multifrequency signal is applied to the interdigitated transducer deposited on the optical waveguide surface. The dependence of diffraction efficiency of the output orders on the intermodulation factors and on the transducer driving radiofrequencies has been investigated. The influence of fabrication parameters of Ti:LiNbO3 waveguides on the linear dynamic range of acoustooptic multifrequency modulators has been extensively studied under monomodal propagation condition. Our results assert that the best performance in terms of linear dynamic range (approximately equals 43 dB) can be obtained on Ti:LiNbO3 waveguides having weak refractive index change ((Delta) n < 0.001), small initial titanium thickness (< 100 angstroms) and medium enter radiofrequency (approximately equals 500 MHz).© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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Recently developed angular rate sensors are all based on two fundamental physical effects, i.e. Sagnac and Coriolis effects. In this chapter these physical effects are briefly discussed to allow the comprehension of different gyroscope... more
Recently developed angular rate sensors are all based on two fundamental physical effects, i.e. Sagnac and Coriolis effects. In this chapter these physical effects are briefly discussed to allow the comprehension of different gyroscope technologies reviewed in the following chapters.
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Integrated optics has led to the development of miniaturized optical devices that have very complex functionality on a single chip. A number of integrated optical devices, such as lasers, amplifiers, multiplexers/demultiplexers, filters,... more
Integrated optics has led to the development of miniaturized optical devices that have very complex functionality on a single chip. A number of integrated optical devices, such as lasers, amplifiers, multiplexers/demultiplexers, filters, modulators and switches have been fabricated in a variety of substrate materials, including crystals, glass, polymers, and semiconductors. In the last few years a considerably research effort has been spent to design and fabricate complex photonic integrated circuits (PICs) in which a number of optical components has been integrated on a single chip. For example, an InP-based PIC including more than 50 optical components has been demonstrated in Nagarajan et al. (IEEE J Sel Top Quantum Electron 11:50–65, 2005).
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In the late 1960s, the development of the fiber optic gyroscope (FOG) was started at US Naval Research Laboratories, Washington (USA) (Brown RB, NRL Memorandum Report N1871, 1968). The exploitation of optical fibers to realize an optical... more
In the late 1960s, the development of the fiber optic gyroscope (FOG) was started at US Naval Research Laboratories, Washington (USA) (Brown RB, NRL Memorandum Report N1871, 1968). The exploitation of optical fibers to realize an optical angular rate sensor was investigated with the hope of reducing cost, simplifying the fabrication process and increasing accuracy with respect to the He–Ne RLG. Despite a considerable research amount during the last decades, FOG has not yet superseded the He–Ne RLG because of the large existing RLG-based industrial infrastructure and the FOG higher sensitivity to external perturbations (temperature changes, vibrations and so on).
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A great research effort has been spent in recent years for the use of guided-wave optoelectronic technologies for signal processing in space applications, because they allow to reduce size, weight, power consumption and system complexity... more
A great research effort has been spent in recent years for the use of guided-wave optoelectronic technologies for signal processing in space applications, because they allow to reduce size, weight, power consumption and system complexity with respect to electronic ones. Based on these motivations, we have conceived, designed and simulated a number of original integrated optical signal processors, such as 2D correlators for imaging reconstruction in SAR applications, both airborne and spaceborne, preprocessors for data classification and identification in satellite applications for remote sensing, beam formers and steerers in active phased array antennas, heterodyne spectrum analyzers, and so on. The substrate materials considered for these circuits are both ferroelectric and III-V semiconductor materials. Original modeling and numerical techniques have been developed to analyze and design the guided-wave components included in the optical architectures. In this paper, the most significant developments of this research activity are reviewed.
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Two configurations of guided-wave planar devices, one on LiNbO3 and one on GaAs, involving noncollinear acousto-optic interaction, are presented, which satisfy the narrowband and wide tunable range filtering requirements. The analysis of... more
Two configurations of guided-wave planar devices, one on LiNbO3 and one on GaAs, involving noncollinear acousto-optic interaction, are presented, which satisfy the narrowband and wide tunable range filtering requirements. The analysis of these configurations is accomplished by a sophisticated fully general model of the acousto-optic interaction in multilayer planar guiding structures, which can take into account the electro-mechanical losses at any diffraction regime. WDM devices have been investigated by considering multimodal optical propagation.
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Light coupling to planar lightwave circuits by means of directional coupling between D-fiber and buried rectangular waveguide is indicated as a viable mean of reducing alignment tolerances in the fiber-pigtailing procedure for integrated... more
Light coupling to planar lightwave circuits by means of directional coupling between D-fiber and buried rectangular waveguide is indicated as a viable mean of reducing alignment tolerances in the fiber-pigtailing procedure for integrated optical devices. The geometry involved is that of a circular fiber core vertically coupled to a rectangular buried waveguide. An accurate analysis by a vectorial formulation of the finite element method is presented of such a coupling geometry in collinear configuration. The structure is analyzed for symmetric and antisymmetric cladding configurations. The power coupling efficiency is investigated in terms of waveguide dimensions and refractive index steps.
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ABSTRACT In this paper, we present the design of a 4 X 4 complete interconnection network, including a new switching element configuration which allows us to reduce the overall dimensions. It is based on the asymmetric passive 3-branch... more
ABSTRACT In this paper, we present the design of a 4 X 4 complete interconnection network, including a new switching element configuration which allows us to reduce the overall dimensions. It is based on the asymmetric passive 3-branch power divider, which allows the beam to be split with half power in the central waveguide and 1/4 power in either lateral waveguide. This structure, which can be inserted in various switching network architectures, has been analyzed using the beam propagation method in order to determine how the various design parameters affect system performances. The total area of the switching element is about 0.6 mm2 for the control voltage of 9.7 V. The total insertion losses are 2.1 dB in the cross state and 1.2 dB in the bar state.
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The effect of neutron and gamma ray irradiations on the optical properties of proton exchanged Z-cut lithium niobate optical planar waveguides were investigated. The damage thresholds were found by optical characterization for waveguides... more
The effect of neutron and gamma ray irradiations on the optical properties of proton exchanged Z-cut lithium niobate optical planar waveguides were investigated. The damage thresholds were found by optical characterization for waveguides exchanged either in pure or diluted proton source.
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ABSTRACT Fiber/D-fiber splice loss can be minimized by precise axes misalignment. We present an accurate analysis of single-mode fiber/D-fiber splice at the telecommunication wavelengths (lambda) equals 1.3 micrometers and (lambda) equals... more
ABSTRACT Fiber/D-fiber splice loss can be minimized by precise axes misalignment. We present an accurate analysis of single-mode fiber/D-fiber splice at the telecommunication wavelengths (lambda) equals 1.3 micrometers and (lambda) equals 1.55 micrometers , by using a combination of vectorial finite element method and mode matching method. Splice loss variation is investigated in terms of fiber axes transverse offset for various D-fiber core-to-flat distances, and the optimum offset that minimizes splice loss is determined. The effect of fiber-axes rotation is also investigated for non null offsets. Fiber axes positioning tolerances are also evaluated for a given percentual loss variation.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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The acousto-optic transducer (AOT) is a fundamental component of a number of guided-wave devices and circuits suitable to the signal processing and optical computing. Most of such devices has been fabricated by using the LiNb03... more
The acousto-optic transducer (AOT) is a fundamental component of a number of guided-wave devices and circuits suitable to the signal processing and optical computing. Most of such devices has been fabricated by using the LiNb03 technology, but some effort has been also spent on components based on lll/V semiconductor technology, i.e. GaAs and related compounds. However, because of the weak piezoelectric effect in these materials, it needs to analyze complex multilayer structures, including an additional ZnO superstrate, which shows an acoustic mode dispersion, due to the dependence of the surface acoustic wave (SAW) propagation speed on the acous.ic frequency applied to the transducer . In this paper a generalized model of the SAW propagation into multilayered structures has been applied to some typical acoustic waveguides, a simple semi-infinite layer of AlxGa-1 _xAs, as a function of the Al title x, a ZnO/AIGaAs structure, and a more complex ZnO/Alx1Ga-|_xiAs/Alx2Gai_X2As/GaAs structure, as a function of the intermediate layer thicknesses, frequency and Al titles x1 and x2.
ABSTRACT In this paper we study an asymmetrically cladded Y-junction in Ti:LiNbO3 in order to investigate the passive polarization splitting behavior related to the action of the buffer layer supposed to cover only one branch. Different... more
ABSTRACT In this paper we study an asymmetrically cladded Y-junction in Ti:LiNbO3 in order to investigate the passive polarization splitting behavior related to the action of the buffer layer supposed to cover only one branch. Different widths of the two arms and appropriate dividing angle are chosen to improve the expected performance. We analyzed the Y-structure by utilizing a bounded step approximation involving the mode-conversion between guided and radiation modes. To evaluate the effective indexes of both modes in each step, we utilized the effective index method by considering the two dimensional refractive index profiles.
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... Agostino Giorgio, Anna Gina Perri* R and Mario Nicola Armenise ... To solve the Maxwell equations in the etched region we have implemented a "ve-order Runge}Kutta}Fehlberg ... search of complex zeros of complex functions we... more
... Agostino Giorgio, Anna Gina Perri* R and Mario Nicola Armenise ... To solve the Maxwell equations in the etched region we have implemented a "ve-order Runge}Kutta}Fehlberg ... search of complex zeros of complex functions we have modi"ed the well-known Muller's method [33 ...
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We present the theoretical investigation, including design criteria, of a new optical beam former for phased-array active antennas. The device is formed by a Z-cut LiNbO channel-planar composite waveguide, an array of interferometric... more
We present the theoretical investigation, including design criteria, of a new optical beam former for phased-array active antennas. The device is formed by a Z-cut LiNbO channel-planar composite waveguide, an array of interferometric modulators and a linear ...