Design of broadband spectrum sampling filter for on-chip computational spectrometers

Abstract

A multi-point self-coupling waveguide spectral shaper for on-chip computational spectrometer is proposed and verified by simulation. The autocorrelation coefficient of the spectral response of the filter has very narrow width of the main lobe, which helps to achieve a high resolution of the spectrometer. Due to the rich design degrees of freedom, each filter with can be designed to exhibit very distinct spectral characteristics, so that only 30 channels are adequate for accurate spectral reconstruction with 100 nm bandwidth and 2.5 nm resolution. Each filter has an ultra-compact footprint less than 4550.4 µm 2 and 30 filters in total occupy a footprint of about 0.13 mm 2 .