In this paper, we present the spatial beam modulator based on electrowetting liquid lens/prism array, in order to realize adjustment of various beams (parallel, convergent, divergent) in three-dimensional space. To calculating the adjustments range of the spatial beam modulator, the optical transfer function (OTF) is derived, according to the theories of geometrical optics, matrix optics and electrowetting. We also establish the simulation model for verifying the correctness of OTF by COMSOL. The results show that the spatial beam modulator can translate, expand, contract, converge and diverge the parallel beam. When the parallel beam is incident on the spatial beam modulator, the maximum translation distance of parallel beam is 0.92mm, and its focal length f can be adjusted in the range of 7.96 mm to ∞ (dual-convex liquid interface) or -∞ to 25.99 mm (dual-concave interface). In addition, the spatial beam modulator can also collimate, converge, diverge the convergent beam or divergence beam.
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