In recent years, the laser fuze has been widely used in minor caliber mortar projectiles and bombs because of its high accuracy in distance measurement, strong ability to resist electromagnetic interference, high angular resolution and good concealment. As a result, it becomes an irreversible tendency to miniaturize the high power of the laser, especially in military applications. This paper aims to study the factors on the output characteristics of the microlasers. Based on the variation of the inversion density of the particle in the resonant cavity derived from the oscillation equation of the LD-pumped passively Q-switched Cr4+:YAG/ Nd:YAG laser, this paper summarizes some key factors which have impacts on the output of LD-pumped passively Q-switched subnanosecond microlasers, including the initial transmission of the absorber, the reflection of output coupler, the length of the cavity and the radius of the pumping laser beam, and gives the conclusion of the simulation, which provides the basis for the design of the passive Q-switched micro lasers which have high power, high repetition frequency and narrow pulse width.
