1.5-μm pulsed semiconductor lasers for LiDAR applications

The 1.5-μm waveband lasers have advantages such as good human eye safety, strong atmospheric penetration ability, high signal-to-noise ratio, and strong anti-interference ability, making them very suitable for long-distance LiDAR applications. In response to the application requirements of various coherent and incoherent LiDAR systems, high-power semiconductor lasers in the 1.5-μm waveband using AlGaInAs multiple quantum well (MQW) materials and ridge waveguide structures have been developed. Based on different epitaxial and resonant cavity structures, distributed feedback (DFB) and FabryPerot(F-P) types of lasers are designed for CW/QCW and pulsed operations, with the pulse width varying from 1 ns to hundreds of ns, and the peak power scaling from hundreds of mW to tens of watts for a single emitter. The output of the laser can be collimated in a TO package or coupled into a single-mode or multi-mode optical fiber. In this work, the laser chip design, device packaging, laser temperature control and current driver, temporal waveforms, and corresponding applications are discussed, and the current technological progress and bottleneck issues are analyzed.