Single-pixel computational spectrometer based on nonlinear spectrum modulation

Computational spectroscopy with modulated light spectrum is especially well-suited for application scenarios where active illumination is needed. Most of the existing computational spectroscopy, however, uses ambient illumination and modulates the signal spectrum that is reflected or transmitted from objects, mainly because of the lack of a light source with effective spectrum modulation. Here, we present a novel computational spectrometer featuring light-source spectrum modulation achieved through polarization-induced nonlinear spectrum modulation, offering a compact and low-cost system apparatus. The modulated spectrum can evolve periodically by managing polarization-induced nonlinear phase as well as pump power, within the range from 1000 nm to 1100 nm . Combining wavelength multiplexing and compressed sensing, we can achieve a minimum spectral resolution of 0.2 nm , which is comparable to the commercial spectrometer. The utilized objects with sparse and non-sparse spectra are successfully reconstructed both in simulation and experiment, within an effective reconstruction spectral range from 1021 nm to 1077 nm .