Experimental implementation of multispectral single-pixel imaging in the shortwave infrared frequency range

A multispectral single-pixel imaging system operating at three wavelengths – 800 nm, 1050 nm, and 1550 nm – was developed for the imaging of natural materials, such as nuts. Spectral multiplexing of structured illumination patterns was realized using optical elements, and radiation modulation was performed using a digital micromirror device. Data on the integral intensity of the radiation scattered from the object was collected using a collecting lens and one InGaAs photodetector. In accordance with the proposed scheme, images of 25 objects at wavelengths of 800 nm, 1050 nm and 1550 nm were reconstructed. The resolution of the obtained images was 64 by 64 pixels, the time of obtaining one image was about 40 seconds. Experimental results demonstrated the successful reconstruction of images of natural samples exhibiting distinct spectral features, confirming the potential of the system for material characterization and classification.