High-performance blue and green laser diodes based on nonpolar/semipolar GaN substrates

Abstract

We present breakthrough performance from green and blue InGaN-based laser diodes fabricated on nonpolar/semipolar substrates. High-power, high-efficiency, and long-lifetime continuous-wave laser operation is demonstrated using these novel crystal orientations. For green wavelengths at 520 nm, we report on continuous wave single mode lasing with75 mW of output power and wall plug efficiencies over 2.3%. In the blue regime we describe single-mode lasers operating with over 23% wall plug efficiency and with output powers greater than 750 mW. These InGaN-based direct-diode lasers offer significant improvement in performance, size, weight, and cost over conventional gas and solid state lasers. Furthermore, these devices exhibit robust operation over a broad temperature range, can be directly modulated and do not contain harmful residual infrared radiation typical of second harmonic generation lasers. These characteristics are salient considerations for such optical devices in battlefield and other security applications.