Investigation of nitrogen lasers for dye laser pumping

The dependence of certain properties of nitrogen lasers on various parameters have been examined and the design of two original nitrogen lasers is presented. The output characteristics of these lasers have been studied as a function of gas pressure, gas flow rate and direction, applied potential, repetition rate, electrode geometry, drive circuitry including the effects of preionization, and the effect of optical feedback by the addition of an optical cavity. The operation of these two lasers in a master oscillator/power amplifier configuration is described and the optimization of this system by varying the drive circuit parameters has been achieved. In the optimized state this configuration produced as much energy per pulse as did the amplifier when operating separately as an oscillator. However, the oscillator/amplifier system produces an output with some additional useful characteristics, such as lower beam divergence and a high degree of polarization. The design of a dye laser which uses a grating at grazing incidence and three mirrors is described. This laser utilizes the polarized output from the oscillator/amplifier system to generate simultaneously two independently tunable wavelengths. A novel pumping arrangement is used which ensures that there is no mode competition between the two wavelengths, that they can have any polarization ratio, that the linewidth of each wavelength can be independently varied and allows the two wavelengths to be generated in different dyes.