A Nd : YAG / Cr4 + : YAG composite crystal passively Q-switched laser with high-output pulse energy is studied both theoretically and experimentally. According to the characteristics of flash lamp pump, the rate equations of nonuniform pump are established. The pulse interval, pulse energy, and pulse width of the output pulse train are analyzed accurately by nonuniform pump. The experimental parameters are optimized by numerical simulation, with Cr4 + : YAG saturable absorber initial transmittance of 14%, output coupling mirror reflectivity of 30%, and cavity length of 9.7 cm. Under the same conditions, the maximum static energy is 954.34 mJ without Q-switch. An output pulse train with four pulses can be obtained at the same pump condition in experimental study. The four pulses energy are 156.5, 151, 149.74, and 145.76 mJ in turn with corresponding intervals of 20.81, 24.16, and 46.03 μs. The average pulse width is 5.72 ns. The Q-switch efficiency is 63.2%. The energy of the four pulses decreases, the pulse interval increases, and the pulse width is basically unchanged. The nonuniform pump theoretical and experimental results are in good agreement.
As a novel cw hybrid laser, the lasing wavelengths lie in the near-IR range and for in the transparency window of the terrestrial atmosphere, diode pumped metastable rare gas lasers (DPRGLs) can be considered as a beam conversion system that produces a high-quality laser beam by passing a diode laser with poor beam quality through the rare gases medium at room temperature. In this paper, a numerical model is set up to describe the kinetic processes and the laser amplification, based the five-level structure, in DPRGL amplifier (DPRGA) system. Influences of the pump power and the cell length on the output laser are simulated and discussed. Such a master oscillator power amplifier (MOPA) system is very promising in achieving high output power for low power DPRGL radiation.