Performance of 980 nm pump laser diodes with GaAs/AlAs graded short period superlattice waveguides

Short period superlattices (SPSs) allow precise control of epitaxial layers and the material quality is generally superior to the equivalent solid solution. These advantages have been utilized in 980 nm pump laser diodes; N.K. Dutta et al. (1992) replaced the In_0.2Ga_0.8As active layer with 4 periods of 1 monolayer of InAs and 4 monolayers of GaAs; T. Hayakawa et al. (1993) used 79 periods of 2 monolayers of GaAs and 2.5 monolayers of Al_0.45Ga_0.55As in the place of GaAs barriers. The superior material quality of SPS should be most advantageous in the waveguide. Lasing photons oscillate along the waveguide before being emitted through the front facet; the loss in this region should be minimized for low threshold and good lasing efficiency. In the paper, we present the performance of 980 nm pump laser diodes with GaAs/AlAs graded SPS waveguides