High-performance CW 1.26-μm GaInNAsSb-SQW ridge lasers

Long wavelength GaInNAsSb-SQW lasers and GaInAsSb-SQW lasers that include a small amount of Sb were successfully grown by gas-source molecular beam epitaxy (GSMBE). We confirmed that Sb reacts in a highly strained GaInAs-GaAs system and GaInNAs-GaAs system like a surfactant, which increases the critical thickness at which the growth mode changes from two-dimensional (2-D) growth to three-dimentional (3-D) growth. The lasers were processed into ridge lasers. The GaInNAsSb lasers oscillated under continuous-wave (CW) operation at 1.258 mum at room temperature. The low CW threshold current of 12.4 mA and high characteristic temperature (T-0) of 157 K were obtained for GaInNAsSb lasers, which is the best result for GaInNAs-based narrow stripe lasers. Further, the GaInNAsSb laser oscillated under CW conditions over 100 degreesC. On the other hand, GaInAsSb lasers oscillated under CW operation at 1.20 mum at room temperature. The low CW threshold current of 6.3 mA and high characteristic temperature (T-0) of 256 K were obtained for GaInAsSb lasers, which is also the best result for 1.2-mum-range highly strained GaInAs-based narrow stripe lasers. We can say that GaInNAsSb lasers are very promising material for a realizing pertier-free access network. Further, the differential gain of GaInNAs-based SQW lasers was estimated for the first time. GaInNAsSb-SQW lasers have the extremely large differential gain of 1.06 x 10(-15) cm(2) in spite of the single-QW lasers; therefore, GaInNAsSb lasers are also suitable for high-speed lasers in the long wavelength region.