Ridge-width dependence on high-temperature continuous-wave operation of native oxide-confined InGaAsN triple-quantum-well lasers

InGaAsN triple-quantum-well (TQW) ridge waveguide (RWG) lasers were fabricated with contact ridge width of 4, 10, 50, and 100 μm, respectively, using pulsed anodic oxidation (PAO). All these lasers worked under continuous-wave operation up to 100/spl deg/C. A clear trend of improved characteristic temperature (T₀) was observed as the ridge width narrowed. Proper choosing of ridge height and optimized PAO process were believed to minimize the lateral spreading current and reduce the scattering losses at the etched RWG sidewall, both of which are beneficial to the narrow ridge lasers operation. High output power of 298.8 mW, low transparency current density of 130 A/cm²/well, and high T₀ of 157.2 K were obtained from InGaAsN TQW 4-μm-width lasers.