Superpixel-based spatial amplitude and phase modulation using a digital micromirror device
| Abstract | We present a superpixel method for full spatial phase and amplitude control of a light beam using a digital micromirror device (DMD)combined with a spatial filter. We combine square regions of nearby micromirrors into superpixels by low pass filtering in a Fourier plane of the DMD. At each superpixel we are able to independently modulate the phase and the amplitude of light, while retaining a high resolution and the very high speed of a DMD. The method achieves a measured fidelity F= 0.98 for a target field with fully independent phase and amplitude at a resolution of 8 8 pixels per diffraction limited spot. For the LG10orbital angular momentum mode the calculated fidelity is F = 0.99993,using 768 768 DMD pixels. The superpixel method reduces the errors when compared to the state of the art Lee holography method for these test fields by 50% and 18%, with a comparable light efficiency of around 5%. Our control software is publicly available. |
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| Authors | S. A. Goorden, J. Bertolotti, A. P. Mosk |
| Year of publication | 2014 |
| Date published | 07/2014 |
| Journal | Opt. Express |
| Volume | 22 |
| Pages | 17999-18009 |
| DOI number | 10.1364/OE.22.017999 |
| Keywords | digital holography, MEMS, phase modulation, Wavefront shaping |