Theoretical analysis of filamentation and fundamental-mode operation in InGaN quantum well lasers

Filamentation and, consequently, output beam quality in InGaN quantum-well lasers are found to be strong functions of quantum-well width because of the interplay of quantum-confined Stark effect and many-body interactions. For an In0.2Ga0.8N/GaN gain medium, the antiguiding factor in a thick 4 nm quantum well is considerably smaller than that for a narrow 2 nm one. As a result, lasers with the thicker quantum well maintain fundamental-mode operation with wider stripe widths and at significantly higher excitation levels.