【摘要】 为了提高器件的可靠性和使用寿命 ,设计并研制了一种将p n结和有源层分开的高功率AlGaAs GaAs单量子阱远异质结 (SQW RJH)激光器 ,发射波长为 80 8nm ,腔长 90 0 μm ,条宽 1 0 0 μm ,其外延结构与通常的 80 8nmAlGaAs GaAs单量子阱半导体激光器的结构不同 ,在p n结和有源区间多了一层p型AlGaAs层 ,其厚度约为 0 1 μm。为减小衬底表面位错对外延层质量的影响 ,在n+ GaAs衬底和n Al0 5Ga0 5As下包层间加一层n+ GaAs缓冲层。对器件进行了电导数测试及恒流电老化实验。与常规AlGaAs GaAs大功率半导体激光器相比 ,远结大功率半导体激光器具有阈值电流Ith偏大、导通电压Vth偏高的直流特性。 30 0 0h的恒流电老化结果表明 ,器件在老化初期表现出阈值电流随老化时间缓慢下降 ,输出功率随老化时间缓慢上升的远结特性更多还原

【Abstract】 For conventional high power quantum well (QW) lasers whose p n junction is located in or near the active region, the dark spot defects (DSDs) and the dark line defects (DLDs) develop and move to the active layer during aging process, which increases non radiative recombination centers and causes device to degrade. As a result, the threshold current increases, while the output power and the differential coefficient decrease at the same time. However, for the RJ lasers, the p n junction is separated from the active layer by the presence of a thin waveguide layer between the active layer and p n junction. The mobile defects are absorbed in the p n junction located outside the active layer because of the electric field of p n junction. Thus, the non radiative recombination centers in the active layer decrease, the degradation of RJ lasers is decided by the degradation of p n junction. Unless the p n junction suffers serious damage, a much longer lifetime and a better reliability may be expected for RJ lasers. We designed and succeeded in fabricating 808 nm AlGaAs/GaAs separate confinement heterostructure(SCH)single quantum well RJ lasers with a cavity length of 900 μm and a stripe width of 100 μm by depositing the material on GaAs substrate with metal organic chemical vapor deposited (MOCVD). Its epitaxial structure is different from the conventional 808 nm AlGaAs/GaAs SQW semiconductor lasers. The SCH active region consists of a 10 nm thick Al 0 07 Ga 0 93 As layer between two 0 1 μm thick p Al 0 3 Ga 0 7 As waveguide layers. One p Al 0 3 Ga 0 7 As layer separates the active layer from the p n junction, and also carries out optical and carrier confinement together with another p Al 0 3 Ga 0 7 As layer. The n and p cladding layers are each 1 3 μm thick. Compared to the conventional 808 nm GaAs/AlGaAs high power SQW laser structure, there is a 0 1 μm thick p AlGaAs layer between the p n junction and active region, as shown in Table 1. To decrease the effect of dislocations in substrate on the epitaxial layer quality, a n + GaAs buffer layer is grown between the substrates and n Al 0 5 Ga 0 5 As lower cladding layer. The DC characteristic of RJ lasers was measured. Compared with the conventional AlGaAs/GaAs high power semiconductor laser, the remote junction (RJ) high power semiconductor laser shows that the threshold current ( I th ) and the threshold voltage ( V th ) are large. During 3 000 hour constant current LD mode aging process, the RJH lasers showed a reduction of threshold current and a fluctuate increase of output power.更多还原