On-chip spectrometers using stratified waveguide filters

We present an ultra-compact single-shot spectrometer on silicon platform for sparse spectrum reconstruction. It consists of 32 stratified waveguide filters (SWFs) with diverse transmission spectra for sampling the unknown spectrum of the input signal and a specially designed ultra-compact structure for splitting the incident signal into those 32 filters with low power imbalance. Each SWF has a footprint less than 1 mu mx30 mu m, while the 1x32 splitter and 32 filters in total occupy an area of about 35 mu mx260 mu m, which to the best of our knowledge, is the smallest footprint spectrometer realized on silicon photonic platform. Experimental characteristics of the fabricated spectrometer demonstrate a broad operating bandwidth of 180nm centered at 1550nm and narrowband peaks with 0.45nm Full-Width-Half-Maximum (FWHM) can be clearly resolved. This concept can also be implemented using other material platforms for operation in optical spectral bands of interest for various applications. Compact spectrometers that are simple and scalable in design can enable many applications. Here the authors demonstrate a silicon photonics based single-shot spectrometer that uses a group of waveguide frequency filters to construct the spectrum.

Automated summary

In this study, an ultra-compact single-shot spectrometer on silicon platform is presented for sparse spectrum reconstruction. It consists of 32 stratified waveguide filters with diverse transmission spectra for sampling the unknown spectrum of the input signal. The fabricated spectrometer demonstrates broad operating bandwidth and narrowband peaks that can be clearly resolved. Compact spectrometers with simple design can enable various applications in optical spectral bands.