Hadamard ghost imaging with a small amount of mask plates based on a spread spectrum

Ghost imaging techniques using low-cost bucket detectors have unrivaled advantages for some wavebands where plane array detectors are not available or where focusing is difficult. In these bands, fine mask plates are the key to implementing high-resolution and quality ghost imaging. However, manufacturing a large number of mask plates is necessary but undoubtedly expensive in traditional Hadamard ghost imaging (HGI). Inspired by the spread spectrum technology, Hadamard ghost imaging based on spread spectrum (HGI-SS) is proposed, in which only two sets of a small number of mask plates are needed to accomplish Nyquist sampling for the object. Their numbers are equal to the lateral pixel resolution and the vertical pixel resolution of the object, respectively. Optical experiments verify the effectiveness of the scheme. For ghost imaging with a resolution requirement of 128 × 128 pixels, HGI-SS needs to prepare only 256 mask plates, while the traditional HGI needs to prepare 16,384 mask plates. HGI-SS may be helpful to expand the pixel resolution of imaging at a relatively low cost of mask plates.