High Pixel Resolution Visible to Extended Shortwave Infrared Single Pixel Imaging with a black Phosphorus-Molybdenum disulfide (bP-MoS2) photodiode

Abstract: High-resolution infrared imagers are currently more expensive than CMOS and CCD cameras, due to costly sensor arrays. Van der Waals (vdWs) materials present an opportunity for low-cost, room temperature infrared photodetectors. Although photodetectors based on vdWs materials show promising performance, creating a megapixel array is yet to be achieved. Imaging with a single vdWs photodetector typically relies on time-consuming mechanical scanning and suffers from low resolution. Single pixel imaging (SPI) offers an affordable alternative to achieve high-resolution imaging, utilizing only one photodetector and a spatial light modulator. Progress in SPI using vdWs material photodetectors has been limited, with only one prior demonstration in the near infrared range (64$\times$64 pixels). In this work, we demonstrate a high-resolution SPI system (1023$\times$768 for visible light and 512$\times$512 for extended shortwave infrared) using a black phosphorus-molybdenum disulfide (bP-MoS$_2$) photodiode, surpassing earlier vdWs material SPI implementations by a factor of 64 in pixel count. We introduce an easy-to-implement edge detection method for rapid feature extraction. We employ compressed sampling and reduce imaging time by a factor of four. Our compressed sampling approach is based on a cyclic S-matrix, which is derived from a Hadamard-based sequence, where each row is a circular shift of the first row. This enables efficient imaging reconstruction via circular convolution and Fourier transforms, allowing fewer measurements while preserving the key image features. Our method for SPI using a vdWs material photodetector presents the opportunity for inexpensive shortwave infrared and midwave infrared cameras, and thus may enable advances in gas detection, biomedical imaging, autonomous driving, security, and surveillance.