Multisensor Compressive Sensing for High Frame-Rate Imaging System in the THz Band

Abstract

We present a compressive terahertz (THz) imaging system utilizing a sparse multisensor array to speed up the acquisition process. Spatially modulated object beam is captured with the multipixel array in the $k$ -space. The sparsity of the proposed array sensor is particularly attractive for heterodyne reception. To realize THz spatial light modulation, photoexcitation of a 420- $\mu$ m-thick silicon wafer illuminated by a commercial optical projector is used. To demonstrate multipixel data acquisition and compressive reconstruction, a gimbal mirror is used in conjunction with a single detector. The prototypical system is capable of recording data at two different Fourier points and can reconstruct 64 × 64 pixel image of a metallic aperture object by using 512 mask patterns at 690 GHz. We also demonstrate that the proposed approach is twice as fast as the single-pixel imager, which requires 1024 masks to achieve similar image quality.