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

•The gain-switched method is more advantageous to obtain short pulses, owing to its simple implementation and low production costs.•Short pulse generation with a width of 25–40 ps with a high peak power from excited state of InAs-InP (113)B quantum dot laser by applying an external optical beam to the laser excited state.•Short optical pulses with high response speeds and peak power are in demand in many fields, such as high-speed optical communication, medical biotechnology, clock distribution, electro–optic sampling systems, etc.•Study incorporates the science and technology underlying quantum electronics. For generating picoseconds or sub-picosecond optical pulses having a moderate peak power, semiconductor lasers are preferred as sources owing to their compatibility, cost-effectivity, easy integrability with other optoelectronic devices, and electrical pumping characteristics. As a result, semiconductor lasers that are based on small-size heterostructures, such as quantum dot lasers, are very promising for such applications. The gain switching characteristics and the effect of laser parameters on the output pulses of an InAs-InP (113)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.