随机散射光波的全局优化调幅聚焦

Focusing of random scattering light by global optimization amplitude modulation

When focusing beyond diffraction-limit through the scattering medium with amplitude modulation by the feedback control algorithm, the grid-by-grid modulation scheme of the continuous sequential algorithm will severely degrade anti-noise performance, which is detrimental to focusing of light under low signal-to-noise ratio environment. To overcome the drawback of the continuous sequential algorithm, the genetic algorithm is introduced to shape the wavefront amplitude of incident light. With the help of its characteristic global optimization strategy, the amplitude of all the grids can be simultaneously modulated and optimized so as to reduce the sensitivity to noise. Simulation results show that the target focus intensity of the genetic algorithm can be hardly affected by noise level, and that the resultant focusing intensity acquired at different noise levels are very close. The focusing intensity value up to 80.67％ that of SNR is ∞ can be achieved even if the noise level rises to SNR is 10dB.