Fast and precise laser beam scanning by nonperiodic grating on a binary micromirror array

Abstract

We report a precise and stable laser beam positioning method with a high scanning speed by a pixelated binary grating (PBG) realized by a compact on-off state digital micromirror device (DMD). The overall procedure for PBG pattern generation is proposed, analyzed, and experimentally verified. The resulting performances correspond to an angular resolution of 0.01 deg and angular repeatability of +/- 2.54 X 10(-4) deg over a beam steering range of +/- 7.5 deg. The scanning speed of 40 deg/s is achieved in continuous scanning with a resolution of 0.01 deg. Arbitrary positions can be targeted in the scanning range with DMD's frame rate of 4000 Hz. To verify its applicability in precision metrology, absolute distances to multiple off-axial targets were determined in parallel with a high speed. This method will open a wider application of DMD in precision LIDARs, three-dimensional calibration of precision machines, and high resolution laser patterning. (C) 2022 Society of Photo-Optical Instrumentation Engineers (SPIE)