The Characteristics of Facet Coatings on Diode Lasers

The effect of the output power with different facet passivation methods on 980 nm graded index waveguide structure InGaAs/AlGaAs laser diodes was studied. The output power of the 980 nm laser diodes with Si passivation, and ZnSe passivation at the front and the back facet were compared. The test results show that output power of the ZnSe passivation method is 11% higher than Si passivation method. The laser diode with the Si passivation film is failure when current is 5.1 A, the laser diode with the ZnSe passivation film is not failure until current is 5.6 A And we analyzed the failure reasons for each method. In conclusion, the method of coated ZnSe passivation on the laser diode facet can effectively increase the output power of semiconductor lasers.