Lipei Song

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Laser speckle contrast analysis (LASCA) is limited to being a qualitative method for the measurement of blood flow and tissue perfusion as it is sensitive to the measurement configuration. The signal intensity is one of the parameters that can affect the contrast values due to the quantization of the signals by the camera and analog-to-digital converter(More)
We investigated the effect of amplitude-modulated (AM) ultrasound (US) on acousto-optic (AO) signals. A phantom was exposed to both AM US and a green laser, and CCD measurements of speckle contrast were made with various exposure times. The results show that the AO signal oscillates at the AM frequency when the CCD exposure time is a fraction of the AM(More)
Shear wave propagation provides rich information for material mechanical characterization, including elasticity and viscosity. This Letter reports tracking of shear wave propagation in turbid media by laser-speckle-contrast analysis. The theory is described, and a Monte Carlo simulation of light shear wave interaction was developed. Simulation and(More)
The parameters of several stratified volume holographic gratings are optimized in order to obtain high diffraction efficiency beam spliters. Two-, three-, five-, seven-, and nine-beam fan-outs are theoretically studied and compared with what has been achieved by other means. With a simple optical setup, a fan-out element that generates seven beams of equal(More)
A three-dimensional (3D) digital reconstruction method for integral imaging with high random-error tolerance based on statistics is proposed. By statistically analyzing the points reconstructed by triangulation from all corresponding image points in an elemental images array, 3D reconstruction with high random-error tolerance could be realized. To simulate(More)
Hologram characteristics of Se(1-x)Ge(x) (x = 0, 3,5,8, 12 wt.%) films were determined in real-time configuration. Parameters such as film thickness, composition, and exposure power influencing the diffraction efficiency were also studied. The maximum value of the diffraction efficiency achieved was 3.2% with 91.0-mW/cm(2) power in films alloyed with 3% Ge.(More)
Optical image encryption, especially double-random-phase-based, is of great interest in information security. In this work, we experimentally demonstrate the security and feasibility of optical image encryption with asymmetric double random phase and computer-generated hologram (CGH) by using spatial light modulator. First of all, the encrypted image(More)
The need to image objects through light-scattering materials is common in a range of applications. Different methods have been investigated to acquire the image of the object when diffusers are presented. In this paper, we demonstrate the object reconstruction with single-shot imaging based on the correlography principle and phase retrieval algorithm with(More)
The effects of the substrate temperature (T(s)) on the optical constants of as-deposited Se and SeGe thin films and on the holographic recording properties of these films were investigated. The substrate temperature held between 35 degrees C and 50 degrees C during thin film deposition was identified as an appropriate means to improve the optical recording(More)
We put forward a method to easily generate a single or a sequence of fully developed speckle patterns with pre-defined correlation distribution by utilizing the principle of coherent imaging. The few-to-one mapping between the input correlation matrix and the correlation distribution between simulated speckle patterns is realized and there is a simple(More)
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