Owing to the requirement of high resolution of imaging system, such as the infrared imaging system, the imaging laser radar, the compressive sensing is used in the imaging system with low resolution sensors to obtain high quality image information. In this paper, compressive sensing is applied in an imaging system. A random phase mask is placed on the lens of the optical system. The optical wave propagation process of light field from the object plane to the lens, then to the image plane is analyzed and theoretical formula of the propagation with the form of the Fourier transform expression is deduced, thus the reconstruction speed is high by using the fast Fourier transform. The orthogonal wavelet transform and the orthogonal matching pursuit algorithm are employed in the reconstruction. The simulation results prove the good performance of the reconstruction quality and speed.
Diffractive optical elements (DOEs) can realize beam shaping with higher light efficiency, strong flexibility of diffraction pattern, and is suitable to be used in optical interconnections to split beams. In order to increase the intensity uniformity of the split beams, a hybrid algorithm merging Gerchberg-Saxton (GS) algorithm with gradient method is presented based on the sampling rule different from the existing optimization algorithms. By controlling N extra points with zero amplitude besides the original N sampling points on the input plane, and finally the sampling pitch on the Fourier plane is half of that of the conventional sampling rule. Then the N extra points on the Fourier plane will be controlled. Finally spot array with high intensity uniformity can be realized with the proposed algorithm. Simulation results demonstrate the good performance of the proposed algorithm.