Hybrid waveguides based on antiresonant reflecting optical waveguide (ARROW) structure on Si substrates is investigated. The core layer of the waveguide is separated from the Si substrate by interference cladding which consists of a high index first cladding layer and a low index second cladding layer. The Ta2O5 first cladding layer was grown by rf magnetron sputtering system. The SiON second cladding layer was deposited by plasma-enhanced chemical vapor deposition (PECVD) based on the reaction of SiH4/N2O mixtures. Typical propagation losses of the waveguides using this SiON material system are less than 0.15 dB/cm. The high quality cladding layers are prepared to form the Fabry-Perot cavities to ensure low loss operation of the ARROW device at antiresonant conditions. Two methods were proposed to demonstrate the enormous applications of hybrid ARROW waveguides. First, polyimide/Ta2O5/SiON ARROWs were fabricated to achieve high extinction ratio waveguide polarizers. This is accomplished by tuning the operating point of the TM0 mode from antiresonant condition toward high-order antiresonance of the second cladding layer utilizing birefringence of the waveguide core. The measured extinction ratio and insertion loss of a 2-cm-long ARROW polarizer are 40 dB and 2.2 dB, respectively. In addition, the temperature dependence of refractive index of organic-inorganic sol-gel glasses was measured by Mach-Zehnder interferometry using the ARROW waveguides. The Sol-gel/Ta2O5/SiO2 ARROWs were fabricated to characterize index-to-temperature coefficients (dn/dT) of the sol-gel glasses because the optical confinement factor of the ARROW is very close to 1. The measured index-to-temperature coefficients of the sol-gel glasses with different compositions are negative and are on the order of 10-4.

The research work presented in this thesis deals with modelling, design and characterisation of passive and active optical waveguide devices. The rst part of the thesis is related to algorithm development and numerical modelling of planar optical waveguides and gratings using the Method of Lines (MoL). The basic three-point central-di erence approximation of the δ2=δx2 operator used in the Helmholtz equation is extended to a new ve-point and seven-point approximation with appropriate interface conditions for the TE and TM elds. Di erent structures such as a high-contrast waveguide and a TM surface plasmon mode waveguide are simulated, and improved numerical accuracy for calculating the optical mode and propagation constant is demonstrated. A new fast and stable non-paraxial bi-directional beam propagation method, called Cascading and Doubling algorithm, is derived to model deep gratings with many periods. This algorithm is applied to model a quasi-guided multi-layer anti-resonant reecting optical waveguide (ARROW) grating polarizing structure. In the second part of the thesis, our focus is on active optical devices such as vertical-cavity and edge-emitting lasers. With a view to improve the bandwidth of directly modulated laser, an InGaAsP quantum well with InGaAlAs barrier is studied due to its favorable band o set for hole injection as well as for electron con nement. Quantum wells with di erent barrier bandgap are grown and direct carrier transport measurements are done using time and wavelength resolved photoluminescence upconversion. Semi-insulating regrown Fabry-Perot lasers are manufactured and experimentally evaluated for light-current, optical gain, chirp and small-signal performance. It is shown that the lasers having MQW with shallow bandgap InGaAlAs barrier have improved carrier transport properties, better T0, higher di erential gain and lower chirp. For lateral current injection laser scheme, it is shown that a narrow mesa is important for gain uniformity across the active region. High speed directly modulated DBR lasers are evaluated for analog performance and a record high spurious free dynamic range of 103 dB Hz2=3 for frequencies in the range of 1-19 GHz is demonstrated. Large signal transmission experiment is performed at 40 Gb/s and error free transmission for back-to-back and through 1 km standard single mode ber is achieved. / QC 20100827