This paper introduces radial multi-sub-mirror (MSM) synthetic aperture system structure and imaging characteristics of the liquid lens based, and the MSM array for the simulate imaging and image restoration. In order to obtain the scaling invariance of MSM system imaging, the dimensionless method is used to reduce the structural parameters. Baseline statistical distribution diagram and modulation transfer function (MTF) are used to analyze the structural characteristics and intermediate frequency(IF) characteristics. The MSM optical characteristics are calculated and the raw image is simulated under different filling factors. For the reduction of the IF characteristics of the synthetic aperture system, the raw image is restored by Wiener filtering. Using the standard deviation and peak signal-to-noise ratio between the synthetic aperture imaging system and the filled aperture imaging system, these two indicators evaluate the image quality with different fill factors. A comparative analysis of the restored images yields a relationship between filling factor and image quality. Since the large number of sub-mirrors in the MSM array, resulting in a larger number of different baselines. Because the baseline corresponds to the distribution characteristics of spatial frequency, the baseline of the MSM has a large number of repeats in the IF region, so the structure has a good response of IF. The results showed that as the sub-aperture diameter increases, the imaging quality of the MSM structure becomes better. The image restoration effect enhance with the increase of the filling factor. After wiener filtering, the image quality is improved.
The optical integrated aperture imaging system arranges several small aperture optical elements according to a certain regular spatial position, and achieves common phase precision on the same focal plane by adjusting the optical path and matching the phase. It is 0.1λ precision. As a high-precision displacement adjustment device, stacked piezoelectric ceramics can realize displacement deformation in the micrometer direction in the longitudinal direction. In this paper, a piezoelectric ceramic tube is stacked and filled with a transparent liquid medium. A compact optical phase modulator is designed and the output is prepared. Using interferometer to detect phase and combined with optimized image processing technology, an optical phase detection method with an accuracy of 0.1λ is obtained, which provides a feasible reference scheme for optical synthetic aperture common phase adjustment.
This article introduced a new type of normally closed micro-valve (NCV) equipped with curved channels and trapezia-shaped valve seat, which could solve the issues of large area of dead zone, high threshold pressure and slow response speed of NCV in the current microfluidic oscillators. The new type of NCV has a three-layered structure with a top controlling layer, medium membrane layer and the bottom feedback layer. The membrane channel in the feedback layer is specifically deigned as curved to decrease the dead zone area. The valve seat is designed as a trapezoid to reduce the adhesion between the membrane and the valve seat and the threshold pressure of the NCV , and to improve the response speed of the system .The results of simulation study on COMSOL shows that this micro-valve structure reduces the NCV threshold pressure by 45% and the oscillation period of the micro-oscillator by 36%. This article conducted further simulation studies on the factors that influence the oscillation period of micro-oscillator. When enlarging inlet flow rate of micro-oscillator, lowering NCV threshold pressure and decreasing valve seat angle, the oscillation period would be reduced. Otherwise, the oscillation period will be increased.