Single-frequency neodymium-glass lasers under nonspiking free-oscillation and Q-switched conditions

An investigation was made of a neodymium-glass laser with an emission line $<5\cdot 10^{-3}$ cm$^{-1}$ wide, operating under nonspiking free-oscillation conditions producing pulses of $\sim700\mu$ sec duration. At threefold excess of the pumping over the threshold the output energy was $\sim30$ J. The radiation emitted by this laser was used to control the radiation of a second neodymium-glass laser, which was $Q$-switched. The $Q$ switching was performed by a rotating prism. When the second laser was injected with narrow-line radiation from the first laser, it produced giant pulses of 30 nsec duration and $0.4$ J energy in the form of a line $7\cdot 10^{-3}$ cm$^{-1}$ wide. In the absence of such injection the natural width of the emission line of the $Q$-switched laser was $\sim14$ cm$^{-1}$.