Photonic Crystal Surface Emitting Lasers (PCSELs) based on Dot in Well (DWELL) Active Region by Epitaxial Regrowth Method

In this study, we explore photonic crystal surface emitting laser (PCSEL) for vertical emission with high beam quality, high room temperature continuous wave output power, compactness, and electrical injection, with less fabrication complexity. The fabrication process involves epitaxial regrowth, where photonic crystals are patterned via electron beam lithography and etched using inductively coupled plasma. We employ dot-in-well (DWELL) active regions, known for superior thermal stability, to mitigate quantum dot (QD) degradation during high-temperature regrowth. Both molecular beam epitaxy (MBE) and metal organic chemical vapor deposition (MOCVD) are explored as a regrowth phase. MOCVD regrowth yielded better crystal quality than MBE. We successfully demonstrate an optically pumped epitaxially regrown DWELL PCSEL with an emission wavelength of 1230 nm operating at room temperature. Furthermore, the DWELL active region shows excellent emission wavelength stability and intensity despite the high temperature regrowth process.