Output Power Characteristics of Microwave-Pulse-Excited He-Kr+ Ion Laser

The output power of a microwave-pulse-excited He-Kr⁺ ion laser has been measured as a function of the microwave power, pulse width, gas pressure, mixture ratio and tube diameter. The optimum condition of laser oscillation has been obtained. In contrast to conventional Ar⁺ and Kr⁺ ion lasers, the He-Kr⁺ ion laser has some different characteristics; P\cdot D product is not constant, the optimum gas pressure increases with increase in the microwave power, and the optimum gas pressure is higher than that of a conventional type. There is a delay-time which is the period between the end of a microwave pulse and the start of a laser oscillation. The dependence of the laser peak power on the delay-time is not influenced by the parameters (microwave power, pulse width, gas pressure, mixture ratio and tube diameter). This means that the effect of the diffusion of the plasma to the wall does not contribute to the population inversion mechanism.