An optically pumped GaN–AlGaN vertical cavity surface emitting laser

An optically pumped GaN‐based vertical cavity surface emitting laser (VCSEL) is demonstrated. Laser emission near 363 nm is observed at room temperature from the surface of a VCSEL structure optically pumped along a cleaved sample edge by focused light from a nitrogen laser. The VCSEL structure, which was grown on a sapphire substrate by metalorganic vapor phase epitaxy, consists of a 10 μm GaN active region sandwiched between 30‐period Al0.40Ga0.60N–Al0.12Ga0.88N Bragg reflectors. At optical pump intensities above ∼2.0 MW/cm2, a narrow (<5 A) laser mode at 363.5 nm emerges from the GaN photoluminescence spectrum. This mode becomes the dominant feature of the spectrum at higher pump powers, and additional modes appear ∼1.3 nm above and below this mode at 362.1 nm and 364.8 nm. The ∼1.3 nm mode spacing corresponds closely with the 1.1 nm spacing predicted from an electromagnetics model of the VCSEL structure.