Department of Electrical & Computer Engineering, University of Michigan Ann Arbor, Ann Arbor, MI, 48109, USA.
Sci Rep. 2017 May 31;7(1):2518. doi: 10.1038/s41598-017-02716-x.
Complex Semi-Definite Programming (SDP) is introduced as a novel approach to phase retrieval enabled control of monochromatic light transmission through highly scattering media. In a simple optical setup, a spatial light modulator is used to generate a random sequence of phase-modulated wavefronts, and the resulting intensity speckle patterns in the transmitted light are acquired on a camera. The SDP algorithm allows computation of the complex transmission matrix of the system from this sequence of intensity-only measurements, without need for a reference beam. Once the transmission matrix is determined, optimal wavefronts are computed that focus the incident beam to any position or sequence of positions on the far side of the scattering medium, without the need for any subsequent measurements or wavefront shaping iterations. The number of measurements required and the degree of enhancement of the intensity at focus is determined by the number of pixels controlled by the spatial light modulator.
复杂半定规划 (SDP) 被引入作为一种新的方法，用于通过高度散射介质的单色光传输的相位恢复控制。在一个简单的光学设置中，使用空间光调制器来产生随机的相位调制波前序列，并且在相机上获取传输光中的相应强度散斑图案。SDP 算法允许从这个强度测量序列计算系统的复透射矩阵，而不需要参考光束。一旦确定了传输矩阵，就可以计算出最优的波前，将入射光束聚焦到散射介质的远侧的任何位置或位置序列上，而不需要任何后续的测量或波前整形迭代。所需的测量数量和焦点处的强度增强程度取决于空间光调制器控制的像素数量。
