RESUMEN
In this work, we demonstrate via computer simulation the single mode and zero birefringence conditions for photonic wires with height and width less than 600 nm. We report on the simulation conditions for both single mode and zero birefringence in silicon-on-insulator photonic wires and sub-micron rib waveguides using a 3-dimensional imaginary beam propagation method. The results show that operation in both single mode and zero birefringence is possible under certain circumstances and that the conditions are restricted by fabrication processes where birefringence is strongly dependent upon waveguide dimensions. A matrix of waveguide parameters has been identified at both operating wavelengths of 1310 nm and 1550 nm, which can satisfy single mode and zero birefringence conditions simultaneously. This is to provide a general design rule for waveguides in small dimensions on the order of hundreds of nanometres.
RESUMEN
A flat spectral response has long been a requirement in photonic networking. In order to find a low cost alternative compared to some other technologies, a novel method is demonstrated to achieve such a response in silicon-on-insulator arrayed waveguide gratings (AWG) through free carrier absorption, implemented by ion implantation of dopant species. The AWG is designed using 1.5mum Si-overlayer on an SOI wafer utilising rib waveguides with a width of 1.1mum and an etch-depth of 0.88mum to facilitate the single-mode, birefringence-free operation. It is also essential to achieve a uniform dopant concentration throughout the guiding region to avoid any phase errors resulting from the free carriers. This can be achieved using multiple ion implantation steps. Both n and p type dopants are investigated and results showed significant reduction of doping length is achieved by using n-type dopant as compared to a p-type dopants. The broadened passband is measured to be 0.5nm, a 5 times broadening from the Gaussian peak.
