High-peak-power short-pulse operation of modulated PCSELs emitting structured light by introducing saturable absorber

Compact, high-peak-power light sources emitting structured light such as multi-dot patterns are desired for face recognition and light detection and ranging (LiDAR) applications, especially in the field of mobile technology. Conventionally, such light sources are composed of VCSEL arrays, lenses, and diffractive optical elements (DOEs), resulting in large and complex systems. To address these issues, we propose and introduce double-lattice structures and saturable absorbers to modulated photonic-crystal surface-emitting lasers (M-PCSELs) capable of emitting arbitrary beam pattens (including structured light) to achieve high-peak-power operation at a low injection current via the Q-switching effect. Considering mobile applications, we experimentally demonstrate short, sub-100-ps pulsed emission of a 28-dot pattern with a total peak power of >5W and narrow divergence angles of <0.5° per dot at an injection of 1A. In addition, by adjusting the carrier lifetime in the saturable absorber, we realize short-pulse operation with a high total peak power of ∼20W at an injection current of 6A.