Ultraviolet laser diodes grown on semipolar [formula] GaN substrates by plasma-assisted molecular beam epitaxy.

We demonstrate ultra-violet laser diodes emitting at 388 nm grown by plasma-assisted molecular beam epitaxy on semipolar [formula]GaN substrates under metal-rich conditions. The threshold current density and voltage of 13.2 kA/cm2 and 10.8 V were measured at room temperature for devices with the laser ridge waveguide oriented along the [formula] direction. We show smooth, atomically flat surface morphology after growth. The excellent structural quality of the laser heterostructure was corroborated by transmission electron microscopy. [ABSTRACT FROM AUTHOR]