Design and fabrication of high power InGaN blue laser diode over 8 W

Abstract The impact of multi quantum wells (MQWs) structure on the homogeneity of spontaneous luminescence and quantum efficiency of the high power InGaN blue laser diode (LD) is numerically investigated. The structure with 2QWs in the active region is found to be the optimal choice for the high power InGaN LD. Accordingly, the edge emitting LD structure is grown and fabricated. To study the facet coating effect on the catastrophic optical damage (COD) level, three types of LDs are coated with different materials by different techniques, respectively. The characterization results confirm that the single blue LD coated with the Al2O3 and Al2O3/Ta2O5 films by electron cyclotron resonance deposition exhibits the highest COD level, due to the better crystal quality and interfacial quality of the coated films. The LD starts to operate at 1.04 kA/cm2 with slope efficiency of 1.8 W/A and the wavelength of 444.9 nm. As a result, the output power as high as 8.04 W is achieved at 5.5 A.