Dependence of threshold current density, carrier lifetime and optical gain coefficient on donor concentration in 1.3 μm n-type modulation-doped strained multiquantum well lasers

The dependence of lasing properties on the donor concentration is experimentally investigated for 1.3 μm n-type modulation-doped (MD) strained multiquantum well (MQW) lasers. The threshold current density has a minimum at a donor concentration of 3×10¹⁸ cm^-3: the carrier lifetime and the optical gain coefficient decrease with the donor concentration. The turn-on delay time of 100 ps can be expected at 85°C when the MD-MQW structure is applied to a low-leakage buried heterostructure laser