Method for improving the diffraction efficiency of a DMD-based projector in the MWIR band

How to improve the diffraction efficiency of DMD is a key issue in enhancing the imaging quality of the MWIR projector, while the effect of the incident angle of DMD on the diffraction efficiency has not been clarified, which leads to the diffraction efficiency of DMD in the MWIR band is still a blank on the influence of the imaging contrast of the optical system. In this study, the diffraction characteristics of DMD in the MWIR band are systematically analyzed, and a projection method based on the highest principal energy level diffraction efficiency of DMD is proposed. By analyzing the two-dimensional flashing grating diffraction model of DMD, the azimuth angle of 45° and the zenith angle of 10.5° are determined to be the optimal incident beam angles of DMD, at which the primary energy level diffraction efficiency is better than 54%.