Customized spectral filters using cladding-modulated Bragg gratings in silicon waveguides.

Abstract

Waveguide Bragg gratings are expected to play an important role in diverse applications of photonic integrated circuits. Here, we present our latest progress in implementing Bragg filters with a customized spectral response in the silicon-on-insulator platform. Our filter comprises a silicon waveguide with an array of Bragg segments placed aside. The waveguide core is designed to have a reduced mode confinement, which enables an accurate control of the grating strength via modulation of the Bragg segment separation distance and allows for minimum feature sizes compatible with deep-UV lithography (>100 nm). Our design strategy is experimentally validated by demonstrating a filter with 20 non-uniformly spaced notches in the transmittance spectrum. Palabras clave: Silicon photonics, Bragg gratings, spectral filters.