A method has been developed to determine the minimum aperture size that a digital micromirror device can accurately render

A digital micromirror device (DMD) is a programmable pixelated instrument that uses an array of tiny individually switchable mirrors as a rapid spatial light modulator. DMDs are used in beams shaping, tunable wavelength selector, digital holography, dynamic 3D displays, and generating binary data. Perhaps the most common use of the DMD is when its incorporated in tiny projects in smart phones, home entertainment centers, and digital cinema projectors. However, there are several issues on how it renders an input image because of the diamond configuration of its mirrors. Without proper calibration and corrections, this diamond pixel configuration limits the application of the DMD. In this research, we put forth a method to determine the smallest limit with which a DMD can render an aperture. Our method depends on the intensity pattern that is produced when an optical vortex beam, a specially designed beam, impinges on the DMD. It depends on the use of the properties of the Fourier
transform and the diffraction of a vortex beam as it passed through an aperture. By varying the size of the triangular aperture uploaded onto the DMD, we can know the smallest aperture it can render. Our research is important especially when DMDs are used to create holograms and apertures for remote sensing.

Authors: Dina Grace C. Banguilan and Nathaniel Hermosa (National Institute of Physics, College of Science, University of the Philippines Diliman)

Read the full paper: https://www.sciencedirect.com/science/article/pii/S0030399224007084