No abstract

Temperature calculations of Texas Instruments' DMD (Digital Micromirror Device) are well known under CW (continuous wave) optical exposure conditions and are described in existing DMD datasheets. However, application spaces are being developed which require the use of pulsed lasers as the illumination source, complicating the DMD temperature calculations. Certain combinations of laser power, pulse widths, and pulsing repetition rate result in acceptable mirror surface temperature while others can create an unreasonable thermal load well outside of acceptable DMD parameters. This paper details transient thermal calculations at the mirror surface, bulk mirror, and silicon die locations using the DMD thermal (RC) time constants along with laser peak power, pulse width, and repetition frequency to help define acceptable operating conditions and avoid conditions outside the capability of the DMD. Pulse widths spanning from continuous to femtosecond and the resulting maximum mirror surface temperature are shown along with the transient temperature profile to understand the response of the mirror.