AR Eyeglasses MEMS mirror Laserbeamscanner RGB laser module LBS Relayoptics Inputcoupler microLED & OLED microLED or OLED (self- emissive) Waveguide Output coupler Projection optics LCoS or DMD (reflective) LCoS & DMD RGB LEDs Illumination optics Inputcoupler Waveguide Output coupler Polarizing beam splitter (PBS) Projection optics Inputcoupler Figure 1. The three waves of light engine technology. (Image: TriLite Technologies GmbH) Trixel® 3 LBS TriLite Calibration Module algorithms Waveguide Output coupler Waveguide Direct coupling without relay optics Figure 2. Optical waveguide with input and output couplers. (Image: TriLite Technologies GmbH) able to make their scanners so small is that their design philosophy has been to perform many of the scanning functions using software rather than hardware. Another significant contributor to the small size is that they use a single two-axis MEMS mirror instead of one for each axis. The optical input coupler is part of the waveguide. The coupler is a pattern of microstructure gratings on the surface that allow the light to enter. There 4 are similar structures on the output side, where the light leaves the waveguide. Optical System The optical system consists of a waveguide with input and output couplers. The image output from the scanner is directly coupled into the waveguide, which is a two-dimensional glass structure. It takes the very small input image - only a couple of millimeters wide - www.techbriefs.com Figure 3. The outputs of the three lasers have to be tightly aligned for a clear image. (Image: TriLite Technologies GmbH) Sensor Technology, June 2022 ST TriLite Feature 0622_1.indd 4 Cov ToC 5/18/22 4:40 PM Panel-based displays Scanning-based displayshttp://www.techbriefs.com http://info.hotims.com/82322-850