Blue laser diodes fabricated on m-plane GaN substrates

Blue laser diodes (LDs) were fabricated on m-plane oriented GaN substrates by atmospheric-pressure metalorganic chemical vapor deposition. Typical threshold current for stimulated emission at a wavelength lambda of 463 nm was 69 mA. Blueshift of the spontaneous emission peak with increasing injection current was examined in LDs fabricated on m- and c-plane GaN substrates. Blueshifts for the m-plane LD (lambda = 463 nm) and the c-plane LD (lambda = 454 nm) with an injection current density just below threshold were about 10 and 26 nm, respectively. These results confirm that the blueshift in quantum-wells fabricated on m-plane oriented substrates is smaller than on C-plane oriented substrates due to the absence of polarization-induced electric fields. (c) 2008 The Japan Society of Applied Physics.