Compact Arrayed Waveguide Grating Devices Based on Small SU-8 Strip Waveguides

Compact 48 × 48 and 23 × 23 arrayed waveguide grating (AWG) devices are realized by using SU-8 strip waveguides fabricated with the process of direct ultraviolet (UV) photolithography. The demonstrated 48-channel and 23-channel AWG devices operating around 1550 nm have a channel spacing of 0.8 nm (100 GHz) and 3.2 nm (400 GHz), respectively. Due to the high index-contrast of the SU-8 strip waveguide, the fabricated AWG has a very compact size of only about 0.22 × 0.47 cm
²
. For the fabricated 100 GHz-spaced AWG, the crosstalk between adjacent channels is less than -15 dB, and the polarization-dependent wavelength is about 0.72 nm (@1543.5 nm). The fabricated 400 GHz-spaced AWG device exhibits a crosstalk of less than -20 dB, a polarization-dependent wavelength of 0.02 nm (@1559.6 nm). Finally the temperature tenability of the present AWG device is also characterized. A 12 nm tuning range is observed as the temperature changes from 25°C to 115°C.