Single-pixel complex-amplitude detection via two-step phase shifting

Single-pixel complex amplitude detection technology is a new type of detection technology that combines structured light field illumination and single-pixel detector to obtain target image information. Compared with existing methods, the proposed scheme offers high detection accuracy, rapid response speed, straightforward architecture, and lower cost, making it highly suitable for applications in optical measurement and astronomical observation. At present, the common scheme of single-pixel complex amplitude detection technology is to build a checkerboard-based common optical path interferometric system. In this scheme, the reference light is introduced through a combination of super-pixel and spatial partitioning, and the complex amplitude of the light field is obtained using the four-step phase-shifting method. The four-step phase-shifting method necessitates the sequential acquisition of phase-shifted interferograms at four distinct instances, thereby imposing limitations on the overall detection rate of complex amplitude. To enhance the detection rate of single-pixel complex amplitude, this paper proposes a technology based on two-step phase shift, which only needs to collect two interferograms with a phase difference of 0 and π/2 to obtain the complex amplitude information of the light field. Numerical simulations demonstrate that the proposed method outperforms the four-step phase-shifting approach by efficiently retrieving complex amplitude information while significantly reducing detection time and enhancing operational speed. These advantages facilitate its application in high-speed complex amplitude detection and offer a promising solution for mitigating issues caused by atmospheric turbulence and optical wavefront distortion.