Search

• The phase detection of physical lenses based on single-pixel common-path off-axis wavefront imaging is demonstrated. • The Fourier fringe analysis can avoid multi-step phase-shifting interference and reconstruct the target object more quickly. • Compared with the previously proposed SPI-based lens phase detection, the measurement speed of our method is increased by at least three folds. • A simple and cost-effective way for lens detection is proposed, which further propels the SPI technology toward practical application. The lens phase provides useful information about the optical path length, from which other key parameters of a lens can be calculated. Yet, the traditional 2D detector-based phase measurement methods are always limited by the specific spectral response range. Here, phase detection of the physical lens is accomplished via a single-pixel detector. The digital micromirror device (DMD)-based common-path off-axis single-pixel (DCOS) wavefront imaging system is established. Benefiting from the advantages of single-pixel detectors, this method is anticipated to be applied in specialist bands. In this method, the wavefront of a target object is reconstructed quickly by Fourier fringe analysis (FFA) from a hologram, which is obtained by the normal SPI technique. Thus, the measuring speed is at least three times faster than that achieved by multi-step phase-shifting. The average relative errors between the measured value and the calibrated value of focal lengths for 1000-mm and 500-mm optical lenses are 0.254% and 0.982%, respectively. Our work provides a fast, simple, and cost-effective way for phase detection of optical lenses and further enlarges the application scope of single-pixel wavefront imaging. [ABSTRACT FROM AUTHOR]

• To guarantee almost the same wavefront imaging quality as Fourier single-pixel imaging (FSPI) does while the imaging speed can be accelerated several folds, a discrete cosine transform single-pixel imaging (DCT-SPI) technique for measuring the spatial wavefront of an unknown field was proposed. • The DCT-SPI technique for measuring different wavefronts as well as its application for quantitative phase imaging of a dragonfly wing was experimentally demonstrated, and its performance was compared with that of FSPI in detail. • Experimental results suggest that the imaging speed of DCT-SPI can be several times faster than that of FSPI, and it can obtain the phase and amplitude of a wavefront with a higher imaging resolution under the RAM capacity limit of the DMD, as compared to the FSPI technique. • The results also suggest that DCT-SPI can 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 the merits mentioned above. 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. [ABSTRACT FROM AUTHOR]