Optimization of AlGaInAs quantum well in semiconductor lasers

In this paper, a diode laser design method based on optimization of the thickness and material composition of the quantum well (QW) in order to achieve the minimum current threshold and maximum output optical power is introduced. In the proposed structure, an asymmetric waveguide structure was used to control the confinement factor and decrease free carrier loss. The laser design, operating at 808 nm, was optimized by using a 10 nm Al 0.126 Ga 0.774 In 0.1 As for the QW and a 900 nm Al 0.4 Ga 0.6 As for the waveguide (WG). The experimental results show that the optical power can be enhanced effectively with the proposed structure. The experimental results also show the slope efficiency in 1 mm cavity length is improved sufficiently to a value of 1.36 W/A. Furthermore, the present QW structure provides internal quantum efficiency and internal loss of 0.93 and 0.38 cm −1 , respectively.