Lasing characteristics of 1.3 μm atomic layer epitaxy quamtum dot laser diode

We demonstrated the room temperature lasing of GaAs-based 1.3 mu m quantum-dot laser diode (QDLD) grown by atomic layer epitaxy (ALE). The active region of a QDLD consists of 3-stacked InAs quantum-dots (QDs) in an In0.15Ga0.85As quantum well (dots-in-a-well: DWELL), which was grown by molecular beam epitaxy (MBE). For advanced performances of QDLD, the high-growth-temperature spacer layer and p-type modulation doping were applied to QDLD active region. We fabricated ridge waveguide structure LDs which had 10 similar to 50 mu m ridge width with several cavity lengths and applied a high reflection (HR) coating on one-sided mirror facet. The threshold current density was 95 A/cm(2) under a pulsed operation and 247 A/cm(2) under a CW operation, respectively. The lasing wavelength was 1.31 mu m under a pulsed operation condition and 1.32 mu m under a CW operation at room temperature. The QDLD showed a simultaneous lasing and a state switching to the higher-order state. The lasing wavelength switching from the ground state to the excited state depends on the cavity length, the injection cur-rent and operating temperature.