We propose a novel method to efficiently correct the aberration in a free-space optical switch, where a spatial light modulator (SLM) is used to control wavefronts. A particle swarm optimization (PSO) method is applied to finding the optimum set of Zernike modes to compensate the aberration. We find out that the obtained coefficients of the lower-order modes and those of the higher-order ones exhibit a linear relationship when the optimization flow is interrupted by the local optima. We can drastically reduce the time for the calibration by using this relationship among the Zernike coefficients.
2010 by The Institute of Electronics, Information and Communication Engineers