Challenges and approaches of fabricating GaN-based green lasers

In this paper we discuss the motivation, challenges, and progress in making group-III nitride lasers emitting in the green spectral range, and compare the devices created using epitaxial structures grown on GaN substrates with c-plane (i.e. plane with (0001) crystallographic orientation) and semipolar-plane (i.e. with the plane tilted from c-plane by >;0 and <;90 degree) orientations. The different structure design choices are discussed, taking into account specific material properties and crystal growth requirements for these orientations.