High-resolution patterning and characterization of optically pumped first-order GaN DFB lasers

DFB gratings in the range of 85.0 to 87.75 nm in effective steps of 0.08 nm have been defined on GaN by electron-beam lithography and transferred into the semiconductor by dry etching. First-order DFB emission at room temperature of optically pumped GaN at an energy of 3.33 eV was demonstrated. We achieved single-mode emission with a line width of 2 meV and obtained very high coupling coefficients in the order of View the MathML source. The temperature dependence of the emission line from room temperature down to 120 K was investigated.