Thermo-Optic Tunable Silicon Arrayed Waveguide Grating at 2-μm Wavelength Band

The transparent window in optical fiber at 2-μm waveband enables a huge potential for fiber optical communications. Intensive efforts have been devoted to pursuit of photonic devices in this new band. The arrayed waveguide grating (AWG) is one of the key components for various functionalities like wavelength multiplexer, optical filter, spectrometer and so forth. However, the integrated and wavelength tunable AWG has not been realized in the 2-μm wavelength range yet. Here, we demonstrate an 8-channel thermo-optic tunable AWG at 2 μm via silicon photonic multi-project wafer shuttle run. The device is fully compatible with standard foundry fabrication process without customization. The TiN heater is designed for uniform waveguide heating and wavelength detuning. Experiments show that the fabricated AWG has a dense channel spacing of 1.6 nm and a minimum insertion loss of 6.1 dB. The wavelength tuning efficiency is measured to be 6.4 nm/W.