Influence of patterned TiO2/SiO2 dielectric multilayers for back and front mirror facetson GaN-based laser diodes

Ridge InGaN multi-quantum-well-structure (MQW) edge-emitting laserdiodes (LDs) were grown on (0001) sapphire substrates bylow-pressure metal-organic chemical vapour deposition (MOCVD). Thedielectric TiOdielectric multilayers, GaN-basedLD, stimulated emission, threshold currentProject supported by the NationalHigh Technology Program of China (Grant No 2007AA03Z403), theNational Natural Science Foundation of China (Grant Nos 60776042 and60477011), and National Basic Research Program of China (Grand No2006CB921607).4255P, 4260D, 8115H, 7280ERidge InGaN multi-quantum-well-structure (MQW) edge-emitting laserdiodes (LDs) were grown on (0001) sapphire substrates bylow-pressure metal-organic chemical vapour deposition (MOCVD). Thedielectric TiOdielectric multilayers, GaN-basedLD, stimulated emission, threshold currentProject supported by the NationalHigh Technology Program of China (Grant No 2007AA03Z403), theNational Natural Science Foundation of China (Grant Nos 60776042 and60477011), and National Basic Research Program of China (Grand No2006CB921607).4255P, 4260D, 8115H, 7280ERidge InGaN multi-quantum-well-structure (MQW) edge-emitting laserdiodes (LDs) were grown on (0001) sapphire substrates bylow-pressure metal-organic chemical vapour deposition (MOCVD). Thedielectric TiOdielectric multilayers, GaN-basedLD, stimulated emission, threshold currentProject supported by the NationalHigh Technology Program of China (Grant No 2007AA03Z403), theNational Natural Science Foundation of China (Grant Nos 60776042 and60477011), and National Basic Research Program of China (Grand No2006CB921607).4255P, 4260D, 8115H, 7280ERidge InGaN multi-quantum-well-structure (MQW) edge-emitting laserdiodes (LDs) were grown on (0001) sapphire substrates bylow-pressure metal-organic chemical vapour deposition (MOCVD). Thedielectric TiO$_{2}$/SiO$_{2}$ front and back facet coatings ascavity mirror facets of the LDs have been deposited withelectron-beam evaporation method. The reflectivity of the designedfront coating is about 50{%} and that of the back high reflectivecoating is as high as 99.9{%}. Under pulsed current injection atroom temperature, the influences of the dielectric facets werediscussed. The threshold current of the ridge GaN-based LDs wasdecreased after the deposition of the back high reflectivedielectric mirrors and decreased again after the front facets weredeposited. Above the threshold, the slope efficiency of the LDs withboth reflective facets was larger than those with only back facetsand without any reflective facets. It is important to design thereflectivity of the front facets for improving the performance ofGaN-based LDs.