Optimization of Tilted Bragg Grating Tunable Filters Based on Polymeric Optical Waveguides

Abstract

A wavelength filter based on a polymer Bragg reflector has received much attention due to its simple structure and wide tuning range. Tilted Bragg gratings and asymmetric Y-branches are integrated to extract the reflected optical signals in different directions. To optimize device performance, design procedures are thoroughly considered and various design parameters are applied to fabricated devices. An asymmetric Y-branch with an angle of 0.3° produced crosstalk less than −25 dB, and the even-odd mode coupling was optimized for a grating tilt angle of 2.5°, which closely followed the design results. Through this experiment, it was confirmed that this device has a large manufacturing tolerance, which is important for mass production of this optical device.