Antonsen Jennings (peppersalt72)

The phase-shifting method is a simple and efficient approach to extract complex hologram information free of bias and twin-image noise. In this study, the geometric phase-shifting method is utilized for a self-interference incoherent digital holographic recording system based on the Michelson-type interferometer. The phase-shifting module consists of a horizontal polarizer, and two achromatic quarter-wave plates are employed inside the interferometer, replacing conventional phase-shifting devices, such as the piezo-actuated mirror. Since the phase-shifting amount of the introduced method herein is theoretical, regardless of the input wavelength, the simultaneous recording of step-wise phase-shifted interferograms for different color channels is available. Therefore, the multi-color hologram recording is achieved with fewer numbers of exposures. The demonstration of multi-color hologram recording and reconstruction are presented to validate the proposed idea.An incoherent optical detection sensor (often referred to as energy or direct detection sensor) used for remote detection and ranging purposes is a useful tool. While the accuracy and robustness of an incoherent sensor relative to a coherent sensor may be lacking particularly in cluttered environments, it has a place in the world due to its simplicity and performance. With this, a best design approach is sought to meet requirements in a stochastic fashion. In developing the design approach, motivations are borrowed from decades of research in radar systems. This article provides a sensor- or top-level design approach for an incoherent optical detection sensor based mainly on paths developed in radar.The coded aperture snapshot spectral imager (CASSI) acquires three-dimensional spectral images with two-dimensional coded projection measurements. This paper proposes an adaptive design method of the coded apertures, according to a priori knowledge of the target scene, to improve sensing efficiency and imaging performance of the super-resolution CASSI system. The adaptive coded apertures are constructed from the nonlinear thresholding of the grayscale map of the scene. Theoretical proof is provided to demonstrate the superiority of the adaptive coded apertures over traditional random coded apertures. Improvement in reconstruction performance is also verified by a set of simulations based on different spectral data.To generate a flat optical frequency comb (OFC), a new scheme based on a dual-parallel Mach-Zehnder modulator and a single recirculation frequency shift loop is proposed and analyzed. check details Compared with the traditional single loop recirculation frequency shift method, the quantity of comb lines is doubled, and the comb flatness is better when the number of cycles is the same. The theoretical analysis model is established, and the simulation results show that a 111-line OFC with frequency spacing of 10 GHz, flatness of 1.32 dB, and optical signal to noise ratio of 27.4 dB can be obtained by adopting the proposed scheme.Three-dimensional (3D) measurement of colorful objects is challenging. As different colors can absorb different wavelengths of projected light, the brightness and contrast of the captured fringe are not uniform when employing single-color light projection, which will lead to measurement error. In this paper, we present a rapid 3D measurement technique for colorful objects employing red, green, and blue (RGB) light projection. According to the research in this paper, for common colors, the pixel with the largest brightness and contrast can be extracted from the three fringes projected by RGB light. Furthermore, we introduce the selection method of exposure time, and then combine the high-speed projection technique with the optimal pixel-extraction algorithm to get the optimal set of fringes for phase calculation. Experiments show that the proposed method improves the measurement accuracy and efficiency.In this paper, we introduce the idea of u