[Comparative study on the performance of deformable mirror of NIR based human eye aberration correction system]

The structure features and spatial characteristics of the two kinds of micro-machined membrane deformable mirrors, OKO 37-element and BMC 140-element, which work in the NIR based human eye aberration correction system, are compared and analyzed. At same time, the principal component analysis was carried out for the influence function of the mirror, the voltage control model was established and the optimal control mode of deformable mirror can be determined by adjusting the control parameter d. Finally, the simulation experiments for fitting aberration of unit Zernike mode and human eye aberration of Thibos model were carried out. The experiment results show that the capability for fitting the each Zernike mode of BMC 140-element mirror is twice more than the OKO 37-element mirror at least. When correcting the Thibos model human eye aberration whose average RMS error is 0.638 lambda (lambda=0.785 microm), the residual RMS error of BMC mirror is 0.063 lambda which achieves the diffraction limit (lambda/14) of the optical system, but the correction capability of OKO mirror is far less than BMC mirror due to the large cross-linked value between actuators, small density distribution of actuators and some other influencing factors, and the residual wave-front RMS error is 0.168 lambda. The methodology can also be used for other types of deformable mirror performance evaluation.