Increased-area oxidised single-fundamental modeVCSEL with self-aligned shallow etched surface relief

A self-aligning fabrication process is presented for enhancing the fundamental singlemode emission of selectively oxidised vertical cavity surface emitting lasers using a surface relief etching technique. The mechanism underlying the increase in threshold gain due to the use of a shallow surface relief is described and the results obtained for a 7 µm device at 850 nm are presented.