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Ferrofluid Based Deformable Mirrors - a New Approach to Adaptive Optics Using Liquid Mirrors

P. Laird·R. Bergamasco·V. Berube·E. F. Borra·A. Ritcey·M. Rioux·N. Robitaille·S. Thibault·L. Vieira da Silva Jr·H. Yockell-Lelievre
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Abstract

The trend towards ever larger telescopes and more advanced adaptive optics systems is driving the need for deformable mirrors with a large number of low cost actuators. Liquid mirrors have long been recognized a potential low cost alternative to conventional solid mirrors. By using a water or oil based ferrofluid we are able to benefit from a stronger magnetic response than is found in magnetic liquid metal amalgams and avoid the difficulty of passing a uniform current through a liquid. Depositing a thin silver colloid known as a metal liquid-like film (MELLF) on the ferrofluid surface solves the problem of low reflectivity of pure ferrofluids. This combination provides a liquid optical surface that can be precisely shaped in a magnetic field. We present experimental results obtained with a prototype deformable liquid mirror based on this combination.

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P. Laird, R. Bergamasco, V. Berube, E. F. Borra, A. Ritcey, M. Rioux, N. Robitaille, S. Thibault, L. Vieira da Silva Jr, H. Yockell-Lelievre. 2002-12-08. Ferrofluid Based Deformable Mirrors - a New Approach to Adaptive Optics Using Liquid Mirrors. https://doi.org/10.1117/12.459065

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