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Optical Characterization Of A Cantilever Array : Toward Integrated Wave Front Correctors And Analyzers For Miniaturized Adaptive Optics Systems

This paper presents the design, optimization and optical characterization of an array electrostatic actuators based MEMS to be used as an adaptive optics component of a portable retinal imaging device. The proposed wave-front corrector is implemented in (CMC) polymump technology and features an array of cantilevers on which planar reflective gold thin films were deposited for characterization purposes. The cantilevers relative deflections will be set based on the output of a wave-front analyzer to correct higher order optical aberrations. For the sake of achieving precise wave front correction, three cantilever sizes were implemented on the chip for a total of 64 cantilevers that will serve as actuators of a deformable mirror in future work. Array of actuators are hindered by the off-plane initial misalignment phenomenon caused by thin films deposition process and mismatches between the cantilevers displacement due to size nonuniformities introduced by the fabrication process. The device total surface is XXX × XXX mm2. The COMSOL simulation of the modeled Large, medium and small size cantilevers predicted maximum deflections of 6, 4 and 2 um respectively at maximum DC voltages of XXX, XXX and XXX respectively. These values are verified by laser interferometry and shown that they can be considerably augmented by omitting the gold deposited layer in future versions of the device.