DCT single-pixel detecting for wavefront measurement

In this work, a checkerboard pattern is used to divide an unknown field into the signal and reference parts, and based on the interference between them, we propose and demonstrate a discrete cosine transform single-pixel imaging (DCT-SPI) technique for measuring the spatial wavefront of an unknown field. Here, the discrete cosine transform (DCT) basis was used for generating the modulation patterns to acquire the spectrum of the wavefront by the phase-shifting technique, and the wavefront to be measured can be retrieved by applying a second-order correlation calculation. We first demonstrate the proposed DCT-SPI can be used for measuring the spatial wavefronts simulated by an amplitude SLM(A-SLM). As compared to the phase-shifting Fourier single-pixel imaging (FSPI) technique, the imaging speed of DCT-SPI is four times faster. In addition, under the RAM capacity limit of a digital micromirror device (DMD), DCT-SPI can realize a higher resolution. Further, we experimentally demonstrate that DCT-SPI can also be used for measuring the phase and amplitude of a dragonfly wing, which suggests it can be applied in the field of quantitative phase imaging with a higher speed and imaging resolution as compared with FSPI.