Room-temperature cw operation of InGaPAs/GaAlAs visible light double heterojunction lasers

Abstract
InGaPAs/GaAlAs double heterojunction (DH) lasers operated continuously at room temperature in the spectral range of 720–730 nm. The DH structure was grown on a GaAs substrate by liquid phase epitaxy, and the laser diode fabrication was the same as V‐channeled substrate inner stripe lasers. The lowest values of a threshold current (Ith) were 145 and 186 mA under pulsed and cw operation, respectively. The characteristic temperature T0 of the Ith was typically 120 K. It was confirmed that the InGaPAs/GaAlAs system has sufficient band‐gap energy difference between the active layer and the cladding layer. Multiple longitudinal and fundamental transverse modes were obtained.