Conventional distance-selective imaging systems use lasers that are large in size, high in power consumption, and high in cost. In order to reduce the system size and reduce the system power consumption and cost, The principles and design methods of two drive circuits for generating narrow pulse lasers based on step recovery diodes SRD (combined with shorted transmission lines) and RF bipolar transistors are discussed, physically fabricated and tested, and the characteristics of the two pulse generators and the factors affecting the pulse width amplitude are analyzed. The experimental results show that the SRD-based method can generate a narrow pulse with a rise time of 456.8 ps, a fall time of 458.3 ps, a pulse width of 1.5 ns, and an amplitude of 2.38 V; the transistor-based method can generate a narrow pulse with a rise time of 903.5 ps, a fall time of 946.1 ps, a pulse width of 824 ps, and an amplitude of 2.46 V, both of which can reach a repetition frequency of 50 MHz. Both design methods can be combined with an external laser diode to achieve excellent short pulse laser output.