Polarization-insensitive arrayed waveguide grating based on a half-etched polarization beam rotator/splitter

In this paper, we present what we believe to be a new solution to the polarization-insensitive AWG, which utilizes a ridged polarization beam rotator/splitter on the 300 nm Si 3 N 4 platform. For the polarization beam rotator/splitter, we optimize the design and demonstrate an extinction ratio of 18 dB. With our polarization rotator/splitter and the multi-input AWG fabricated on the same chip, we show a good spectrometer performance for both TE and TM polarizations, with a contrast ratio around 18 dB. Our design offers a polarization-insensitive spectrometer that can be fabricated using a simple, fully CMOS-compatible process while maintaining a broad operational wavelength range.