Super-resolution AWGs based on the Moirè effect

Enhancing spectral resolution in a conventional arrayed waveguide grating AWG requires a longer differential optical path, which expands the device footprint and increases sensitivity to phase noise. To overcome this limitation, we propose an innovative approach that maintains the AWG layout and introduces an additional splitter at the device input. Leveraging the Moirè effect, generated by two gratings with slightly different pitches, we demonstrate that the spacing of 7 channels multiplexer/demultiplexer can be reduced to $1$ GHz at the central wavelength of 1550 nm. We present the theoretical foundation for a super-resolution AWG and provide the corresponding design guidelines.