Two-step phase-shifting single-pixel complex amplitude detection technique

Single-pixel complex amplitude detection offers significant potential for applications in biomedical imaging, three-dimensional topography measurement, adaptive optics, and related fields. However, conventional interferometric methods require four phase-shifting steps to reconstruct intensity and phase, limiting the detection speed. This paper introduces a novel two-step phase-shifting technique that requires only two phase-shifted intensity measurements and one DC measurement for reconstruction. We develop a theoretical model and conduct numerical simulations. Then experimentally compare the four-step and two-step methods and validate the generality of the model by testing different illumination patterns. The proposed method not only achieves detection quality comparable to the conventional four-step approach but also improves the detection speed by approximately 33 % , demonstrating a significant advance in single-pixel imaging technology. • The complex amplitude can be determined from two phase-shifted and one direct current measurement. • This scheme enables an approximate 33 % increase in detection speed for almost all common-path models. • The performance of the proposed scheme has been comprehensively evaluated through both simulations and experimental studies.