An experiment using the phenomenon of percolation has been conducted to demonstrate the implement... more An experiment using the phenomenon of percolation has been conducted to demonstrate the implementation of neural functionality (summing and sigmoid transfer). A simple analog approximation to digital percolation is implemented. The device consists of a piece of amorphous silicon with stochastic bit-stream optical inputs, in which a current percolating from one end to the other defines the neuron output, also in the form of a stochastic bit stream. Preliminary experimental results are presented.
2017 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD), 2017
In both science research and product development of waveguides based chips fiber-waveguide coupli... more In both science research and product development of waveguides based chips fiber-waveguide coupling is a mandatory stage. In this work, the universal fiber-waveguide coupling efficiency is analyzed based on the overlap model of fiber and waveguide profiles. Furthermore, the systematic numerical simulations with gap size, matching material and birefringence show that the waveguide-gap interface reflection plays a dominant role in polarization dependent loss (PDL). For the two cases: this interface reflection is (i) involved and (ii) eliminated, the resulting numerical PDL values are 1.08dB and 0.06dB, respectively. The simulations from the professional simulators are sustainable to the above numerical results.
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 [email protected]
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.
IEE Proceedings H Microwaves, Optics and Antennas, Aug 1, 1980
It is shown that the acoustically-induced phase modulation of coherent light propagating within a... more It is shown that the acoustically-induced phase modulation of coherent light propagating within an insonified multimode optical fibre may be linearly detected using heterodyne and space diversity techniques. This allows a performance comparable to a monomode optical fibre acoustic sensor to be obtained, but with relaxed mechanical alignment tolerances.
Journal of the Optical Society of America, Jul 1, 1985
Optical wave mixing of arbitrary-profile beams in model materials exhibiting different material r... more Optical wave mixing of arbitrary-profile beams in model materials exhibiting different material responses are investigated by asymptotic methods. The coupled-wave equations of previous theories are shown to be special cases of the equations governing the evolution of the zeroth-order term of a classical asymptote in wavelength solution. The classical theory is then generalized by reformulating the problem as a nonlinear integral equation, which is solved by a combination of Picard's iteration and the method of stationary phase. This permits more satisfactory handling of phase-mismatched waves and may be extended to take into account boundaries, discontinuous initial conditions, and foci. The convergence criteria for the iteration also establish the existence and the uniqueness of the solution. The method may be applied equally to other forms of nonlinear material response. The coupledwave equations are solved numerically for the case of real-time correlation by degenerate four-wave mixing and are compared with experimental results by using photorefractive Bi 12 SiO 20. The results obtained demonstrate the significant effect of the interaction-region geometry and the material response on the correlation fidelity.
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 ...
An experiment using the phenomenon of percolation has been conducted to demonstrate the implement... more An experiment using the phenomenon of percolation has been conducted to demonstrate the implementation of neural functionality (summing and sigmoid transfer). A simple analog approximation to digital percolation is implemented. The device consists of a piece of amorphous silicon with stochastic bit-stream optical inputs, in which a current percolating from one end to the other defines the neuron output, also in the form of a stochastic bit stream. Preliminary experimental results are presented.
2017 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD), 2017
In both science research and product development of waveguides based chips fiber-waveguide coupli... more In both science research and product development of waveguides based chips fiber-waveguide coupling is a mandatory stage. In this work, the universal fiber-waveguide coupling efficiency is analyzed based on the overlap model of fiber and waveguide profiles. Furthermore, the systematic numerical simulations with gap size, matching material and birefringence show that the waveguide-gap interface reflection plays a dominant role in polarization dependent loss (PDL). For the two cases: this interface reflection is (i) involved and (ii) eliminated, the resulting numerical PDL values are 1.08dB and 0.06dB, respectively. The simulations from the professional simulators are sustainable to the above numerical results.
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 [email protected]
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.
IEE Proceedings H Microwaves, Optics and Antennas, Aug 1, 1980
It is shown that the acoustically-induced phase modulation of coherent light propagating within a... more It is shown that the acoustically-induced phase modulation of coherent light propagating within an insonified multimode optical fibre may be linearly detected using heterodyne and space diversity techniques. This allows a performance comparable to a monomode optical fibre acoustic sensor to be obtained, but with relaxed mechanical alignment tolerances.
Journal of the Optical Society of America, Jul 1, 1985
Optical wave mixing of arbitrary-profile beams in model materials exhibiting different material r... more Optical wave mixing of arbitrary-profile beams in model materials exhibiting different material responses are investigated by asymptotic methods. The coupled-wave equations of previous theories are shown to be special cases of the equations governing the evolution of the zeroth-order term of a classical asymptote in wavelength solution. The classical theory is then generalized by reformulating the problem as a nonlinear integral equation, which is solved by a combination of Picard's iteration and the method of stationary phase. This permits more satisfactory handling of phase-mismatched waves and may be extended to take into account boundaries, discontinuous initial conditions, and foci. The convergence criteria for the iteration also establish the existence and the uniqueness of the solution. The method may be applied equally to other forms of nonlinear material response. The coupledwave equations are solved numerically for the case of real-time correlation by degenerate four-wave mixing and are compared with experimental results by using photorefractive Bi 12 SiO 20. The results obtained demonstrate the significant effect of the interaction-region geometry and the material response on the correlation fidelity.
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 ...
Uploads
Papers by Trevor Hall