title: 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 LG10 orbital 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.
authors.forename: Sebastianus A
authors.initials: SA
authors.lastname: Goorden
authors.forename: Jacopo
authors.initials: J
authors.lastname: Bertolotti
authors.forename: Allard P
authors.initials: AP
authors.lastname: Mosk