JL Ramsey and TJ Hall Photonic Network Technology Laboratory, Centre for Research in Photonics, S... more JL Ramsey and TJ Hall Photonic Network Technology Laboratory, Centre for Research in Photonics, School of Information Technology and Engineering University of Ottawa, 800 King Edward, Ottawa, Ontario K1N 6N5, Canada jramsey@site.uottawa.ca
Optical phase conjugation is an important nonlinear process, with many applications in the areas ... more Optical phase conjugation is an important nonlinear process, with many applications in the areas of optical communications and optical processing. This is as a result of the wave-front correction properties that phase conjugation offers and this has generated much interest in the area. A common method of producing phase conjugated wavefronts is the four-wave mixing interaction and many publications on the steady state solution to this problem have appeared over the last decade. More recently, however, interest has been focussed upon the temporal behaviour of four-wave mixing systems, with instabilities and chaos being both demonstrated by Gauthier et al [1] and predicted by Królikowski et al [2]. To date, the analysis for the temporal behaviour of anisotropic four wave mixing, in the transmission grating regime, has involved the direct numerical integration of the equations describing four wave mixing. This analysis however, does not utilise the symmetries of the four wave mixing process, and thus results in a more complex problem. Through exploitation of these symmetries the complexity of the problem has been reduced from one containing four complex variables, to one containing three real variables. This has been accomplished through the use of the Special Unitary Group 2, a group providing a two dimensional matrix, whose elements are functions of three real variables. The multiplication of this matrix, together with one containing the boundary conditions for the problem, thus enables the four complex beam amplitudes to be reexpressed in terms of three real quantities. Using this technique, the temporal nature of anisotropic four wave mixing has been studied, and shown under certain conditions, to exhibit chaotic behaviour when an electric field is present. The effect of any material absorption on the chaotic nature is also demonstrated.
Novel algorithms based upon Mueller matrix terms m are presented herein. These allow the recovery... more Novel algorithms based upon Mueller matrix terms m are presented herein. These allow the recovery of the spectra of incident TE and TM orthogonal states of polarization, which yield polarization-dependent frequency shifts and other parameters of interest. This solution involves little computational efforts and has significantly improved the testing capacity and capabilities of the Test and Measurement group of MetroPhotonics Inc.
In this work, a strategic deep trenching with theoretical optimization is adopted to reach a succ... more In this work, a strategic deep trenching with theoretical optimization is adopted to reach a successful reflective effect of WTC structure. The experimental results are within the reasonable range. We select the SOS refractive index difference of 0.75%, waveguide core size of 5.5 μm × 5.5 μm. We know, only the trench bottom is at the same depth as the waveguide core, the side-wall can reflect the guided-mode from an input waveguide to an output waveguide, so set the trenching depth of 26 μm, which is realized with the inductively coupled plasma (ICP) dry etching technique. Such a deep trenching process has to face the critic challenge in the bottom position and angle of trench side-wall as well as the roughness. At 1.55 μm wavelength, we have experimentally observed the output guided-mode and then measure the average optical loss of each WTC structure is 11 dB, implying that an optical reflective efficiency of 8% has been reached.
In this paper we discuss enhancement techniques for use with BSO and Ga As. These techniques incl... more In this paper we discuss enhancement techniques for use with BSO and Ga As. These techniques include application of electric fields both a.c. and d.c. We consider the effects of crystal orientation and of beam polarisation and present results for two wave mixing in BSO and Ga As. For Ga As results we propose absorption gratings to fully explain our results. We show that the 43m structure of Ga As makes,it ideally suited for a four-wave mixing configuration with positive feedback.
By using two orthogonally-polarized pump beams, an ultrabroad tunable wavelength converter is dem... more By using two orthogonally-polarized pump beams, an ultrabroad tunable wavelength converter is demonstrated with uniform efficiency and equalized signal-to-noise ratio (SNR) through four-wave mixing (FWM) in an 1500-nm semiconductor optical amplifier (SOA). This ...
ABSTRACT The coupling of two waves in barium titanate is described in terms of scattering matrice... more ABSTRACT The coupling of two waves in barium titanate is described in terms of scattering matrices derived from a vector coupled wave theory. Key mechanisms responsible for the processes of self-pumped phase conjugation and beam fanning are identified, and the role of reflections from the internal faces of the crystal are examined. The nonlinear effects observed in the crystal are considered in terms of theory and methods of controlling the photorefractive coupling strength in the crystal are considered. Applications for controlling the coupling in photorefractive crystals are also considered.
In optical ring networks, the impact of residual fiber dispersion on the cascadability limit of t... more In optical ring networks, the impact of residual fiber dispersion on the cascadability limit of the optical add-drop systems due to in-band crosstalk is investigated. An experimentally verified re-circulating non-zero dispersion shifted fiber (NZ-DSF) loop model is used to ...
JL Ramsey and TJ Hall Photonic Network Technology Laboratory, Centre for Research in Photonics, S... more JL Ramsey and TJ Hall Photonic Network Technology Laboratory, Centre for Research in Photonics, School of Information Technology and Engineering University of Ottawa, 800 King Edward, Ottawa, Ontario K1N 6N5, Canada jramsey@site.uottawa.ca
Optical phase conjugation is an important nonlinear process, with many applications in the areas ... more Optical phase conjugation is an important nonlinear process, with many applications in the areas of optical communications and optical processing. This is as a result of the wave-front correction properties that phase conjugation offers and this has generated much interest in the area. A common method of producing phase conjugated wavefronts is the four-wave mixing interaction and many publications on the steady state solution to this problem have appeared over the last decade. More recently, however, interest has been focussed upon the temporal behaviour of four-wave mixing systems, with instabilities and chaos being both demonstrated by Gauthier et al [1] and predicted by Królikowski et al [2]. To date, the analysis for the temporal behaviour of anisotropic four wave mixing, in the transmission grating regime, has involved the direct numerical integration of the equations describing four wave mixing. This analysis however, does not utilise the symmetries of the four wave mixing process, and thus results in a more complex problem. Through exploitation of these symmetries the complexity of the problem has been reduced from one containing four complex variables, to one containing three real variables. This has been accomplished through the use of the Special Unitary Group 2, a group providing a two dimensional matrix, whose elements are functions of three real variables. The multiplication of this matrix, together with one containing the boundary conditions for the problem, thus enables the four complex beam amplitudes to be reexpressed in terms of three real quantities. Using this technique, the temporal nature of anisotropic four wave mixing has been studied, and shown under certain conditions, to exhibit chaotic behaviour when an electric field is present. The effect of any material absorption on the chaotic nature is also demonstrated.
Novel algorithms based upon Mueller matrix terms m are presented herein. These allow the recovery... more Novel algorithms based upon Mueller matrix terms m are presented herein. These allow the recovery of the spectra of incident TE and TM orthogonal states of polarization, which yield polarization-dependent frequency shifts and other parameters of interest. This solution involves little computational efforts and has significantly improved the testing capacity and capabilities of the Test and Measurement group of MetroPhotonics Inc.
In this work, a strategic deep trenching with theoretical optimization is adopted to reach a succ... more In this work, a strategic deep trenching with theoretical optimization is adopted to reach a successful reflective effect of WTC structure. The experimental results are within the reasonable range. We select the SOS refractive index difference of 0.75%, waveguide core size of 5.5 μm × 5.5 μm. We know, only the trench bottom is at the same depth as the waveguide core, the side-wall can reflect the guided-mode from an input waveguide to an output waveguide, so set the trenching depth of 26 μm, which is realized with the inductively coupled plasma (ICP) dry etching technique. Such a deep trenching process has to face the critic challenge in the bottom position and angle of trench side-wall as well as the roughness. At 1.55 μm wavelength, we have experimentally observed the output guided-mode and then measure the average optical loss of each WTC structure is 11 dB, implying that an optical reflective efficiency of 8% has been reached.
In this paper we discuss enhancement techniques for use with BSO and Ga As. These techniques incl... more In this paper we discuss enhancement techniques for use with BSO and Ga As. These techniques include application of electric fields both a.c. and d.c. We consider the effects of crystal orientation and of beam polarisation and present results for two wave mixing in BSO and Ga As. For Ga As results we propose absorption gratings to fully explain our results. We show that the 43m structure of Ga As makes,it ideally suited for a four-wave mixing configuration with positive feedback.
By using two orthogonally-polarized pump beams, an ultrabroad tunable wavelength converter is dem... more By using two orthogonally-polarized pump beams, an ultrabroad tunable wavelength converter is demonstrated with uniform efficiency and equalized signal-to-noise ratio (SNR) through four-wave mixing (FWM) in an 1500-nm semiconductor optical amplifier (SOA). This ...
ABSTRACT The coupling of two waves in barium titanate is described in terms of scattering matrice... more ABSTRACT The coupling of two waves in barium titanate is described in terms of scattering matrices derived from a vector coupled wave theory. Key mechanisms responsible for the processes of self-pumped phase conjugation and beam fanning are identified, and the role of reflections from the internal faces of the crystal are examined. The nonlinear effects observed in the crystal are considered in terms of theory and methods of controlling the photorefractive coupling strength in the crystal are considered. Applications for controlling the coupling in photorefractive crystals are also considered.
In optical ring networks, the impact of residual fiber dispersion on the cascadability limit of t... more In optical ring networks, the impact of residual fiber dispersion on the cascadability limit of the optical add-drop systems due to in-band crosstalk is investigated. An experimentally verified re-circulating non-zero dispersion shifted fiber (NZ-DSF) loop model is used to ...
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