Monolithic Integration of a Silica-Based Arrayed Waveguide Grating Filter and Silicon Variable Optical Attenuators Based on p–i–n Carrier-Injection Structure

We demonstrate the monolithic integration of a silica-based arrayed waveguide grating (AWG) filter and silicon (Si) variable optical attenuators (VOAs) by connecting them with spot-size converters (SSCs). The AWG is based on a silica waveguide with an index contrast (Δ) of ~3%, and the Si VOA is based on a rib-type Si wire waveguide with a p–i–n lateral diode structure. The integrated device performs wavelength demultiplexing in 16 channels and has fast optical power attenuation with a -3 dB bandwidth of 50 MHz in each channel.