Line narrowing and frequency stabilization of high-pressure CO/sub 2/ laser by means of injection locking with multi-isotope master oscillator

By seeding radiation from a multi-isotope CO/sub 2/ master oscillator, single-longitudinal-mode operation of a high-pressure CO/sub 2/ laser with conventional isotopes was realized even at the valley of its gain spectrum between adjacent lines. Spectral characteristics were investigated by the heterodyne detection technique and the frequency up-shift and the subsequent down-chirp were identified as a result of transient refractive index change caused by electron density decay during the build-up of laser pulses. The system was coupled with an electronic feedback loop, and attained the frequency stability of less than /spl plusmn/5 MHz.<
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