Optical performance simulation of a digital micromirror device in far- to near-ultraviolet wavelengths

We present a simulation of the optical efficiency of a DLP7000-series digital micromirror device (DMD) in farto near-ultraviolet (UV) wavelength regime. DMDs are spatial light modulators that enable multi-object spectroscopy for UV astronomy. The optical performance of DMDs in this wavelength regime is not well characterized due to practical difficulties in simulating (significant computing power requirements) and measuring (need for a UV test facility) the performance of the device. This work builds off previous research conducted in the visible to infrared wavelength regime and simulates the performance of DMDs in terms of optical efficiency in the UV. Three-dimensional electromagnetic finite-difference time domain simulations are conducted with the DMD illuminated by an f/20 diffraction-limited point spread function across multiple locations on the face of a micromirror. The electromagnetic near-field output is transformed to the far-field to obtain intensity as a function of solid angle, or radiant intensity. Using a simulated collection aperture, we calculate efficiency from 150 nm to 300 nm.