| abstract |
A Fourier transform spectrometer on a silicon substrate and a method for obtaining a reconstructed spectrum of a light source, the spectrometer comprising a waveguide input coupler, a cascaded optical switch, a non-equi-arm subwavelength grating (SWG) waveguide pair and a germanium-silicon detector , and the cascaded optical switches are connected through pairs of unequal arm SWG waveguides. By adjusting the optical switch state and gating the optical path, a series of non-equi-arm Mach-Zehnder interferometer (MZI) arrays with different optical path differences are formed to realize the Fourier transform spectrometer based on spatial heterodyne coherence, and use the compressed sensing algorithm Reconstruct the spectrum. Compared with the traditional passive MZI array structure, it can effectively reduce the chip size and increase the number of sampling points; the unequal arm SWG waveguide pair can effectively improve the chip temperature stability and expand the working bandwidth. The invention can meet the application requirements of the Fourier transform spectrometer for miniaturization and portability, and can solve the problem that the spectrometer on the existing silicon substrate is generally sensitive to temperature. |