Gain-switched short pulse generation from InAs-InP (113)B quantum dot laser excited state

The gain switching characteristics and the effect of laser parameters on the output pulses of an InAs-InP (1 1 3)B quantum dot laser are investigated for the first time using theoretical models to obtain shorter pulses by applying an external optical beam to the laser excited state. The model is based on the rate equations, which are solved by the Runge -Kutta method. The results showed that without an optical beam, long pulse widths are obtained because of the ground state transition, and the change in the parameters strongly affects the laser output. However, with an optical beam illumination, short pulses with a width of 25-40 ps with a high peak power are generated owing to the excited state transition at low currents, and the change in the laser parameters does not affect the output pulses strongly. These results are important for long-distance optical transmissions as well as medical biotechnology.