High-Peak-Power, Ultra-Sensitive Tx/Rx System on Board

Advanced and novel printed circuit board (PCB) and electronic design methods will be used to reduce or eliminate cross-coupling and electromagnetic interference on miniature PCBs that contain high-peak-power pulsed-laser diodes, or vertical cavity surface-emitting lasers (VCSELs), and wideband high-gain optical receiver electronics. In Phase I, the team will develop and apply novel PCB design, layout techniques, and electronic design methods that allow a laser diode transmitter circuita junction laser diode or VCSEL with 3-8 ns pulse width and > 20 W peak powerto co-exist with a 1-mm-square high-speed photodetector receiver, so that the detector within 3 ns to 300 ns after the laser pulse is transmittedis capable of detecting echoed pulses with peak power as low as 50 nW (1 nW goal) incident on the detector. In Phase I, a laser rangefinder PCB, smaller than 6 cm2, which contains the laser diode and supporting drive circuits, photodetector, and custom readout integrated circuit (ROIC), will be characterized. The performance will be compared to modeled results, and areas for improvement identified. The measured data will inform the design of a robust transmitter-receiver system on board (SOB) to be built in Phase II.