Solid-state laser technology

There exists a need for laser systems with wavelength diversity and a high energy per pulse. This may be achieved with an Nd:YAG oscillator amplifier system operated either at 1.06 or 1.33μ. Methods of obtaining oscillation at 1.33μ by suppressing the oscillation at 1.06 μ are presented. The energy per pulse from a laser oscillator can be increased by minimizing thermal problems. One method of accomplishing this is spectral filtering of the flash-lamp output. Experimental results obtained for an Nd:YAG oscillator operating at 1.33 μ with various filters are presented. The energy per pulse can be further increased by the use of a laser amplifier. The effects of the amplifier on a laser pulse are investigated analytically for both circular and Gaussian cross-section beams. This investigation includes the effects of the amplifier saturation, the temporal distortion of the output pulse, and the distortion of the output intensity profile. The analytical results are compared with an experimental Nd:YAG amplifier operating at 1.06 μ.