Unveiling the Potential of Photonic Crystal Surface Emitting Lasers: A Concise Review

Abstract Traditional semiconductor lasers, despite their versatility, face significant challenges in beam control, power output, and temperature sensitivity. Photonic crystal surface emitting lasers (PCSELs) overcome these limitations by employing a two-dimensional photonic crystal structure, enabling large-area, high-power, coherent laser emission with narrow beam divergence and narrow linewidth. This review offers a comprehensive overview of PCSEL technology, concentrating on its design principles, fabrication processes, and potential applications. We trace the development of PCSELs from their initial demonstration in 1999 to recent breakthroughs achieving 50W output power with ultra-narrow beam divergence. Furthermore, we explore the fundamental design principles of PCSELs, including mode analysis, threshold current, and injection design. The key steps in PCSEL fabrication are outlined, with a focus on methods such as regrowth epitaxy and transparent conductor deposition. Finally, we compare PCSELs with established semiconductor laser types, highlighting their applications and future prospects.