title: Flat spectral response silicon arrayed waveguide gratings via ion implantation.
abstract: 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.
authors.forename: Soon T
authors.initials: ST
authors.lastname: Lim
authors.forename: Ching E
authors.initials: CE
authors.lastname: Png
authors.forename: Seong P
authors.initials: SP
authors.lastname: Chan
authors.forename: Graham T
authors.initials: GT
authors.lastname: Reed