Abstract
High-peak-power semiconductor lasers with sub-nanosecond pulse widths are crucial for various applications
including eye-safe remote sensing and non-thermal focused ultrafine material processing. In this
paper, we describe the recent progress of short-pulse, high-peak-power photonic-crystal surface-emitting
lasers (PCSELs). First, we demonstrate PCSELs with 2D arranged saturable absorbers, which enable
high-peak-power, short-pulse operation in the fundamental mode while suppressing lasing in higher-order
modes. Second, we propose the concept of self-evolving PCSELs, where the lattice constant of the
photonic crystal is spatially graded. In the proposed device, the spontaneous transition from a high-loss
state to a low-loss state is induced even without saturable absorbers, leading to short-pulse generation
with a 100-W-class peak power and 30-ps pulse width. Finally, we propose PCSELs based on simultaneous
absorptive and radiative Q-switching, and demonstrate short-pulse generation with an even higher
(~200 W) peak power.
