C/L-band colorless ONU based on polymer bidirectional optical subassembly

A colorless ONU is demonstrated on the polymer-based hybrid integration platform. Polymer Bragg gratings provide power-efficient wavelength tuning over the C-band. Thin-film element is inserted in the waveguide circuits for C/L band splitting and bi-directional transmission. On-chip U-groove and 45 degrees mirror allow submount-free and passive attachment of optical fiber and photo detectors, respectively. Arrays of deep-etched air trenches are introduced for cross-talk suppression. With an optical wavelength rejection level larger than 34 dB, 10-Gb/s bidirectional transmission and detection are achieved.