Laser beam scanning based AR display applying resonant 2D MEMS mirrors

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Laser beam scanning based AR display applying resonant 2D MEMS mirrors

正文部分：
来源：Proc. SPIE 11765, Optical Architectures for Displays and Sensing in Augmented, Virtual, and Mixed Reality (AR, VR, MR) II, 1176503 (27 March
2021); doi: 10.1117/12.2579695,

发表时间：2021年11月9日

Oleg Petrak, Fabian Schwarz, Leon Pohl, Marcel Reher, Christian Janicke, Jan Przytarski,

Frank Senger, Jörg Albers, Thorsten Giese, Lars Ratzmann, Peter Blicharski, Stephan

Marauska, Thomas von Wantoch, Ulrich Hofmann

OQmented GmbH, Fraunhoferstraße 3, 25524 Itzehoe, Germany;

Fraunhofer ISIT, Fraunhoferstraße 1, 25524 Itzehoe, Germany;

ABSTRACT：Presented is a high-resolution AR micro display based on Laser Beam Scanning (LBS) applying a two-dimensional resonantly operated vacuum packaged MEMS mirror with large mirror diameter, high scan frequencies, high Q-factor and large field-of-view (FoV). The image is projected to the retina using a diffractive waveguide leading to a comfortably large eyebox. Advanced control algorithms and image processing methods are implemented to accurately drive, sense and control the biaxial resonant MEMS mirror as well as to optimize image projection quality. Due to a sufficiently large mirror diameter this micro display does not need any beam expansion optics between MEMS mirror and waveguide enabling an ultra-compact projection unit. Resonant operation of the MEMS mirror in both axes and exploiting the significant advantage of a hermetic vacuum package effectively reduces energy loss by damping and thus minimizes drive voltage and power consumption. The display setup demonstrates the successful realization of a small form factor high resolution micro projector that meets important requirements for enabling fashionable AR smartglasses.

Keywords: Biaxial MEMS mirror, Laser Beam Scanning, AR display, smartglasses, diffractive waveguide, low-power, large eyebox, resonance.