The novel facet coating technology for 808nm semiconductor laser

A novel facet coating technology is presented by studying catastrophic optical mirror damage mechanism of semiconductor laser. In this technology, semiconductor laser are cleaved in the air, and the surface oxide layer is removed with a low energy ion source, flowed immediately by coating the facet with thin ZnSe layer of 20 nm. The function of this layer is to protect semiconductor laser facet, and prevent impurity particles diffusing to the facet. Finally the facet is coated with oxidative optical film. The test results show that the output power of the semiconductor laser with the ZnSe coated layer is 13% higher than that of the Si coated layer, and 47% higher than that of the oxide coated film. The device coated oxide film is damaged when current is 4.5 A, and the device coated with Si layer is damaged when current is 5.5 A, the final failed device is coated with ZnSe layer. In conclusion, the method of coating ZnSe layer on the semiconductor laser facet can prevent effectively the catastrophic optical mirror damage, and increase the output power of semiconductor lasers.