Range extension of a bimorph varifocal micromirror through actuation by a Peltier element

Paterson, Alan and Bauer, Ralf and Li, Li and Lubeigt, Walter and Uttamchandani, Deepak (2015) Range extension of a bimorph varifocal micromirror through actuation by a Peltier element. IEEE Journal of Selected Topics in Quantum Electronics, 21 (4). 2701007. ISSN 1077-260X

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    A bimorph varifocal micromirror actuated thermoelectrically by a Peltier element is reported. The single crystal silicon micromirror is 1.2 mm in diameter with a centered 1 mm diameter gold coating for broadband reflection. The actuation principle is capable of varying the micromirror temperature above and below the ambient temperature, which contributed to a 57% improvement in the addressable curvature range in comparison to previously reported electrothermal and optothermal actuation techniques for the device. Altering the device temperature from 10 C to 100 C provided a mirror surface radius of curvature variation from 19.2 mm to 30.9 mm respectively. The experimental characterization of the micromirror was used as a basis for accurate finite element modeling of the device and its actuation. Negligible optical aberrations are observed over the operating range, enabling effectively aberration-free imaging. Demonstration in an optical imaging system illustrated sharp imaging of objects over a focal plane variation of 212 mm.

    ORCID iDs

    Paterson, Alan ORCID logoORCID: https://orcid.org/0000-0003-1255-3254, Bauer, Ralf ORCID logoORCID: https://orcid.org/0000-0001-7927-9435, Li, Li, Lubeigt, Walter and Uttamchandani, Deepak ORCID logoORCID: https://orcid.org/0000-0002-2362-4874;