A design of computational spectrometer based on waveguide grating filters with varied period number

Driven by advances in spectroscopic technology, the development of high-resolution, low-cost, and structurally simple spectrometers has emerged as a key research objective. In this work, we present a design scheme for a computational reconstruction spectrometer based on waveguide grating filters. Waveguide grating filters serve as the sampling units, where each filter features identical grating period and duty cycle. By only tuning the number of grating periods, distinct transmission spectra can be obtained, thereby achieving diverse spectral sampling. Using the CVX algorithm for spectral reconstruction, the simulation results demonstrate that the proposed scheme can achieve the reconstruction of continuous and sparse spectra within the wavelength range of 1400nm to 1700nm, and the resolution of reconstructed spectral can reach 0.1nm. The scheme simplifies the design structure and is easy to fabricate, providing a novel idea for the design of computational reconstruction spectrometer.