Output power and its limitation in ridge-waveguide 1.3 μm wavelength quantum-dot lasers

摘要

Low-threshold (3.7 mA) high-power (150 mW) ridge-waveguide lasers based on 1.3 μm self-organized quantum dots were fabricated and studied at and above room temperature. The output power spectrum of these lasers consists of two components, which correspond to the ground-state (～1.29 μm) and the excited-state (～1.22 μm) optical transitions. The ground-state component of the lasing mode saturates with increase in the drive current and then persists. Further growth of the total output power is due to the excited-state component. Design criteria of quantum-dot lasers, which maximize the ground-state output power, are considered by solving the carrier-photon rate equations. Current-induced ground-to-excited-state lasing transition is due to a combination of slow carrier capture/relaxation to and efficient thermoionic emission from the ground-state level.