531 nm Green Lasing of InGaN Based Laser Diodes on Semi-Polar {20\bar21} Free-Standing GaN Substrates

Abstract

Lasing in pure green region around 520 nm of InGaN based laser diodes (LDs) on semi-polar {201} free-standing GaN substrates was demonstrated under pulsed operation at room temperature. The longest lasing wavelength reached to 531 nm and typical threshold current density was 8.2 kA/cm2 for 520 nm LDs. Utilization of a novel {201} plane enabled a fabrication of homogeneous InGaN quantum wells (QWs) even at high In composition, which is exhibited with narrower spectral widths of spontaneous emission from LDs than those on other planes. The high quality InGaN QWs on the {201} plane advanced the realization of the green LDs.