Effect of hysteresis on the single-frequency emission range of a gas laser

The present work carries out calculations of the effect of hysteresis on the range of single-frequency emission in a gas laser with an absorption cell within the cavity for the case when the difference between nonsaturated gain and losses is greater than zero in a range of frequencies smaller than the intermode interval. It is shown that in the presence of hysteresis, the width of the emission band for one frequency depends on the direction in which the cavity frequencies are scanned. Emission regimes are possible where scanning in one direction leads to emission at one frequency, while scanning in the other direction leads to emission at two frequencies. Theoretical results were confirmed experimentally with a He-Ne laser (1.15 microns wavelength) with a neon absorption cell.