Ring gas laser under gain modulation conditions

A theoretical investigation is made of the amplitude and frequency responses of a ring gas laser to modulation of the gain of the active medium. The amplitude-frequency and phase-frequency characteristics are obtained for modulation of the average intensity, difference between the intensities, and deviation of the beat frequency of the opposite waves. The limits of efficient modulation of these parameters are determined. Modulation of the difference between the intensities and of the deviation of the beat frequency of the opposite waves becomes stronger in a certain range of the laser parameters and for certain frequencies of the gain modulation. An explanation is given of this effect.