Physical and mechanical properties of a TIR-based liquid micro deformable mirror

A deformable mirror based on the principle of total internal reflection (TIR) of light from an electrostatically deformed liquid-air interface was realized and used to perform closed-loop adaptive optical correction on a collimated laser beam aberrated by a rotating phase disk. The liquid system was characterized including open- and closed-loop frequency responses, determination of rise-times, the damping times of the liquid, and the influence of liquid surface motion in the absence of external optical aberrations. The dynamic behavior of the liquid was found to be dominated by gravity waves and the results of the experimental realization were in good agreement with the predictions of the theory. A miniaturization of the system promises to eliminate the dominant gravity waves and considerably reduce the errors introduced by ambient vibrations. Here we explore the possibilities of such a micro mirror and establish the boundary conditions and requirements for its realization.