3.2 W GaN‐Based Photonic‐Crystal Surface‐Emitting Laser

Photonic‐crystal surface‐emitting lasers (PCSELs) have emerged as promising light sources for high‐power, high‐brightness applications such as LiDAR, free‐space communication, and material processing, owing to their unique capabilities for single‐mode operation and narrow beam divergence. However, extending PCSELs into the blue wavelength regime remains challenging, primarily due to the low refractive index and short wavelength of GaN‐based materials, which weakens optical feedback and increases the fabrication difficulty and optical scattering loss, resulting in very high lasing thresholds. In this work, we demonstrate regrowth‐free, watt‐class GaN‐based PCSELs operating at 430.5 nm, fabricated on GaN substrates using an optimized epitaxial structure and photonic crystal design. The device achieved a threshold current density of 4 kA/cm 2 , and a peak output power of 3.2 W at room temperature, which, to our knowledge, is the highest output power reported. This work provides a viable pathway toward high‐power visible PCSELs with simplified fabrication processes, offering significant potential for high‐brightness lighting and display applications in the future.