Influence Of The Gain On The Pulse Waveform And Field Distribution In The Q-switched Laser

In this paper, Laser diode end-pumped solid laser as the research object, based on the numerical solving the rate equation, influence of spatial intensity distribution of pump light on transverse modes distribution in cavity are discussed. Above problems are analyzed in two output patterns which are continuous output and pulse output. only TEM00、TEM10and TEM20were considered.First of all, for pulse laser, by the analysis of energy storage and release during the Q-switched process, the algorithm theoretical model of the Q-switched process is built. The modes distribution is obtained by photon numbers of each transverse mode after the output power is controlled.In the simulation process, the ideal Gaussian beam is chosen as the pumped beam source, with pumping power, pumping radius and pumping location change, the figure of the modes distribution as function of the spatial intensity distribution of pump light are obtained.It is reversed that increasing the pumping power, reducing the pumping radius and pumping in the cavity central axis will help increase the laser’s power and drop the pulse width,improving the beam quality.The calculate results in this paper has some reference value to the Design for laser. Through adjusting the parameters of pump light, the laser beam with better beam quality can be obtained.