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In the process of entangled optical quantum imaging, the Digital Micromirror Device (DMD) sampling mode affects imaging efficiency, and in the process of image sparse reconstruction, the use of a fixed sampling matrix affects the quality of image reconstruction. In this circumstance, this paper proposes an entangled optical quantum imaging method based on Adaptive Block Compressed Sampling with Two-Dimensional Information Entropy (ABCS-2DIE), which measures the texture details of the image through the two-dimensional information entropy of the image, adaptively allocates the sampling rate for each image block according to the texture distribution of the image, and designs the corresponding sampling matrix to sparsely sample the reference light. In addition, coincidence counting between the reference and signal light is considered in the reconstruction algorithm to obtain the target image. Experimental results show that compared with the Overall Compressive Sampling (OCS) method, the proposed method greatly shortens the imaging time and significantly improves the imaging quality. Besides, compared with the Fixed Block Compressed Sampling (FBCS) method, the image obtained by the proposed method has obvious improvement in visual effect, and the corresponding Peak Signal-to-Noise Ratio (PSNR) is improved by 2–4 dB with a slight increase in computation complexity. In all, the proposed method can make good use of the texture features of the image, effectively improving the quality of quantum imaging while reducing the imaging time. [ABSTRACT FROM AUTHOR]

Due to the high penetrability of ultrasonic signals in scattering media, photoacoustic imaging based on photoacoustic effect is of great significance in the research of non-destructive testing and imaging of biological tissues. However, multiple light scattering will occur after the laser is incident on the scattering medium, resulting in poor imaging quality or inability to image. In this paper, we propose a novel method for wavefront shaping and photoacoustic imaging based on a photoacoustic transmission matrix. We use the photoacoustic transmission matrix method as the algorithm for wavefront shaping, and combine the superpixel method with a digital micromirror device (DMD) to modulate the amplitude and phase of the incident light, resulting in an enhancement factor of 10.75 for the photoacoustic signal. Then, we realize photoacoustic scanning imaging by moving the two-dimensional translation stage to drive the absorber above. Compared with the inability to image the initial photoacoustic signal before shaping, the shaped photoacoustic signal can obtain a clear photoacoustic image with a contrast ratio of 16.85. The wavefront shaping and photoacoustic imaging of photoacoustic signals based on photoacoustic transmission matrix method have a good prospect in the imaging of weaker photoacoustic signals. [ABSTRACT FROM AUTHOR]

The diffraction of an orbital angular momentum (OAM) beam behind slits and polygon apertures has enabled the measurement of light's topological charge (TC). In this work, we present a simple technique to measure higher TCs using Hadamard-coded apertures programmed in a digital micromirror device (DMD). Apart from pattern recognition, a common approach in relating the topological properties of the beam with its diffraction, we demonstrate that we can determine TCs from m = ± 1 to ± 10 using the position of diffracted intensity centroid R. We show thru experiments and simulations that indeed the centroids of the diffracted beams move depending on the magnitude and the sign of the TC, and the order N of the Hadamard aperture. Based on our results, distinguishing the TC of a beam is easier when | m | > 5. Lastly, we infer the source of the movement of the centroid using simple interference of three points derived from a Hadamard N = 2. By tracing the position of the zeroth-order maxima in the interference, we relate the maximum intensity position with the intensity centroid position in the diffraction. Our technique is crucial for determining higher-order modes whose TC are difficult to determine with the currently available methods. [ABSTRACT FROM AUTHOR]

The combination of three visible lasers with different wavelengths (Red/Green/Blue) illuminates a digital micro-mirror device (DMD) to generate color images, which is the core of a color imaging or display system. However, conventional optical configuration methods using a light-coupling combination produce the position mismatch of three images generated by DMDs because the diffraction angle of three wavelength beams is different. In this work, we propose a new color combination method using a separate secondary beam-combination structure (SSBCS) to achieve the complete mismatch of three images. The SSBCS can freely control the beam direction of a laser and the image shift is controllable, which can be used to compensate for the position mismatch of three images. Experiments indicate that the proposed method yields a high-quality combination of three images. The proposed methods can directly solve the color combination issue of three visible beams in an optical hardware aspect without the soft-compensation of the DMDs. [ABSTRACT FROM AUTHOR]

In this paper, a single pixel echelle spectrometer system based on compressed sensing theory is proposed. The Digital Micromirror Devices (DMD) is used as the Coding board, and the photomultiplier of high sensitivity point detector is used as the signal receiver. According to its structural characteristics, the optical system of the whole system is designed. The energy concentration of the spot in a single micro mirror can reach 70%. At the same time, the spectral information reconstruction algorithm is studied. Through the nonlinear recovery algorithm, when the compression factor is 20%, the original two-dimensional spectrum is reconstructed, and the two-dimensional spectrum is transformed into the required one-dimensional spectrum through the spectrum reduction algorithm. [ABSTRACT FROM AUTHOR]