The Design and Characterization in Amplitude and Phase of a Compact 8-channel Loop-back AWG based Integrated Comb processor

This paper presents the design and characterization of an 8-channel integrated comb source spectral processor based on an arrayed-waveguide grating in loop-back configuration, with a channel spacing of 100 GHz. The arrayed waveguide grating has an unconventional mounting, for improved aberration and sidelobes. The design of the arrayed-waveguide grating, following a mathematical modeling method, is covered. The method presented gives an accurate result with the need for little computational power and no need for specific software. The devices, fabricated in a silicon nitride platform, are characterized for their spectral responses. The spectral processor is also characterized for both its amplitude modulation as well as the phase modulation. The phase modulation is characterized using optical frequency domain interferometry.