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<P> A study of the reliability of semiconductor distributed feedback diode lasers is presented using the degree of polarisation of photoluminescence (DOP). Two figures of merit, v and w, are developed and used to characterise device aging times and performance. v measures the strain gradient between the top and middle of a device by calculating the difference in an area-averaged DOP between the middle and top of a fixed area of the device. w measures the average strain profile across the top of the device by taking the difference in an area-averaged DOP between the region immediately beneath the ridge and the regions to the immediate right and left of it. Further, the influence of aging and the nature of metal contact are explored as they relate to these metrics. </p> <P> Finite element fits to the DOP and rotated degree of polarisation of photoluminescence (ROP) are presented. The models thus generated are used to explain the nature of the strain observed in different devices. </p> / Thesis / Master of Applied Science (MASc)

Polymer matrices doped with a dispersion of noble metal nanoparticles combine the strong plasmon resonance-based optical signatures of the latter with the flexibility and processability of the former. We have developed a nonlinear lithographic technique to generate large populations of epoxide waveguides containing a uniform dispersion of Au nanoparticles. The method is based on the self-trapping of multiple beams of white light propagating through a catonic polymerizable matrix doped with a gold salt, initiating the polymerization of epoxide moieties and simultaneously the in situ synthesis of elemental Au nanoparticles. Each white light filament inscribes a cylindrical waveguide, leading to an array of metallodielectric waveguides. Field of view (FOV) measurements indicate that the metallodielectric waveguide array has a nearly 59 % increase in FOV relative to its all-dielectric counterparts and can be tuned through the concentration of Au nanoparticles and the optical intensities employed to generate waveguides. / Thesis / Master of Science (MSc)

Electroabsorption and electrorefraction were studied in GaAs/AlGaAs and InP/InAsP multiple quantum well waveguides. Measurements of changes of the absorption coefficient and the refractive index with wavelength and bias voltage were made. Switching ratios of up to 18 dB were obtained for the GaAs/AlGaAs material. The Kramers-Kronig relation was used to calculate the theoretical phase shifts from the absorption coefficient data. / Thesis / Master of Engineering (ME)

This thesis aims at investigating the feasibility of realizing antireflection (AR) and high-reflection (HR) to the semiconductor waveguide end facet using monolithically integratable deep-etching technology to replace the conventional thin film dielectric coating counterpart. Conventional AR coating and HR coatings are the building blocks of semiconductor optical amplifier and semiconductor lasers. In this thesis, the AR coating and HR coating are first studied systematically and comprehensively using two computational electromagnetics approaches: plane wave transmission matrix method (TMM) and finite difference time domain (FDTD) method. The comparison of the results from the two approaches are made and discussed. A few concepts are clarified based on the different treatment between the AR coatings for bulk optics and those for semiconductor waveguide laser structure. The second part uses the same two numerical tools and more importantly, the knowledge gained from the first part to analyze and design deep-etched waveguide gratings for the advantage of ease of monolithic integration. A variational correction to the TMM is provided in order to consider effect of the finite etching depth also in the plane wave model. Specially, a new idea of achieving AR using deep-etched waveguide gratings is proposed and analyzed comprehensively. A preliminary design is obtained by TMM optimization and FDTD verifications, which provides a minimum power reflectivity in the order of 10-5 and a bandwidth of 45nm for the power reflectivity less than 10-3. In order to eliminate the nonphysical reflections from the boundary, the perfectly matched layer (PML) absorbing condition is employed and pre-tested for antireflection analysis. The effects of etching depth and number of etching grooves are specifically analyzed for the performance of proposed structures. Numerical results obtained by FDTD method indicate a promising potential for this alternative technologies. / Thesis / Master of Engineering (ME)

Metal-semiconductor-metal (MSM) photodetectors are becoming attractive devices for optoelectronic integrated circuits due to their high speed and simplicity. Optoelectronic matrix switches based on MSM detector arrays offer many advantages such as zero-bias off-state, low bias voltage, high speed and large bandwidth. While in many applications the optical input is coupled in through the top surface of the device, optical signals can also be distributed through transparent waveguides that are located below the absorbing detector layer. Such waveguide-coupled detectors will act as optical taps when the coupling between the waveguide and detector layers is well under control. In this thesis, a 4x4 MSM waveguide-coupled optoelectronic matrix switch was demonstrated and analyzed. The strength of the coupling between the waveguide and detector layers was predicted theoretically and confirmed experimentally. Franz-Keldysh effect in this device was also demonstrated. / Thesis / Master of Engineering (ME)

No / In this paper, low profile planar Metamaterial-Inspired coplanar fed waveguide antenna is presented for WLAN and Ultra-Wideband applications. The antenna is based on a simple strip loaded to a rectangular patch and zigzag E-shape metamaterial-inspired unit cell. The idea behind the proposed antenna is to enable miniaturization effect. The proposed antenna can provide dual band operation, the first one is a Wi-Fi band at 2.45 GHz having impedance bandwidth of 150MHz, the second one is an ultra wide band extended from 4.2 GHz to 6.5 GHz. Two antennas are designed and fabricated with and without metamaterial-inspired loading. The simulated and measured results regarding Return loss (S11), Gain and Radiation pattern are discussed.