Solid-state block-based pulsed laser illuminator for single-photon avalanche diode detection-based time-of-flight 3D range imaging
A laser diode illuminator for single-photon avalanche diode detection-based pulsed time-of-flight 3D range imaging is presented. The illuminator supports a block-based illumination scheme and consists of a 16-element custom-designed common anode quantum-well laser diode bar working in the enhanced gain switching regime and lasing at ∼810 nm. The laser diode elements are separately addressable and driven with gallium nitride drivers, which produce current pulses with a width of ∼2 ns; the current pulse amplitude was estimated from the supply voltage (90 V) as 5 to 10 A. Cylindrical optics are used to produce a total illumination field-of-view of 40 × 10 deg2 (full width at half maximum) in 16 separately addressable blocks. With a laser pulsing frequency of 256 kHz and laser pulse energy of ∼8.5 nJ, the average optical illumination power of the transmitter is 2.2 mW.