Experimental investigation of the dependence of the difference frequency of a ring laser on the active-medium gain

An experimental investigation was made of the dependence of the difference frequency on the gain of the active medium (in which the discharge current was varied) of a ring helium-neon laser emitting at λ = 0.63 μ. The results obtained were in satisfactory agreement with the theory. These results made it possible to estimate the contribution of the homogeneous saturation of the gain profile to the dependence of the difference frequency on the output power.