Violet InGaN/GaN/AlGaN-Based Laser Diodes Operable at 50°C with a Fundamental Transverse Mode

A violet InGaN multi-quantum-well (MQW)/GaN/AlGaN separate-confinement-heterostructure laser diode (LD) was grown on epitaxially laterally overgrown GaN on sapphire. The threshold current density was 3.9 kA/cm2. The LDs with cleaved mirror facets showed an output power as high as 30 mW under room-temperature continuous-wave (CW) operation. The stable fundamental transverse mode in the near-field patterns was observed at an output power up to 30 mW. The lifetime of the LDs at a constant output power of 5 mW was more than 1,000 h under CW operation at an ambient temperature of 50°C. The estimated lifetime was approximately 3,000 h under these high-power and high-temperature operating conditions.