The Study Of High-power Semiconductor Laser Diode Facet Passivation

With the advantages of small volume, high efficiency and simple modulation, the high power semiconductor lasers have been received widespread attention and application. However, catastrophic optical damage(COD) seriously limits the maximum output power and the reliability of LDs. COD is caused by the high surface state density which leads to the absorption of the laser radiation and the narrowing the bandgap when the cavity surface works under high power density. In order to increase the COD threshold, we have studied the sulfur passivation technology, RF N2 plasma cleaning technology. Main contents are as follows:1. A sulfur-passivation technique for facet of 980 nm laser diodes(LD) has been investigated. The treatment of facet of LD can improve the output characteristics and reliability. Output power increases by 17%. The time of sulfur-passivation produces great difference on the passivation result of LD. The experiment indicates that long time passivation can dam age facet causing degradation of LD. 5 min sulfur-passivation is best.2. The ion bombardment and nitrogen cavity passivation were implemented to the facet of 980 nm Semiconductor lasers. The treatment of the facet of 980 nm Semiconductor lasers can improve the output characteristics and COD power. Output power increases by 30%. Lasers passivated of nitrogen no evidence of degradation after the aging experiment. Lasers of non- nitrogen passivation severely degrades. The results show that part of the nitrogen ions left in the cavity surface place when testing the lasers passivated of nitrogen by the Auger spectroscopy analyzer(AES). The content of nitrogen increased from 0% to 20%, while the content of oxygen from 61% to 30%.The results indicate that the device reliability can be improved.In a word, we have enhanced the COD threshold by passivation technology in this paper. These results are in favor of the lasers working under high power and high reliability conditions.