Wavelength and time-multiplexed multi-channel lidar transmitter for topographic mapping

We demonstrate a multi-channel architecture for nsec pulsed lidar transmitter, scalable to larger channel counts via wavelength- and time-multiplexing in a multi-stage Yb-fiber amplifier. This technology enables lidar systems for topographic mapping missions, requiring much greater spatial coverage and range resolution. We demonstrate prototype hardware, where wavelength channels at 1060nm, 1061nm and 1064nm are multiplexed, and precise 1.3nsec pulse using LiNbO3 electro-optic(EO) modulators, at a combined repetition rate of 1MHz, with equal time interleaving between the wavelengths. The multiplexed pulses are amplified to >20W average power, in an optimized three-stage Yb-fiber amplifier system. We show simple de-multiplexing and frequency-doubling of one of the wavelengths (1064nm). Highspeed FPGA based control provides for independent and programmable control of the pulse rate, timing trigger, pulsewidth, and the intra-pulse-pattern for improved detection schemes.