Allowance for the distribution of the field in a resonator in determination of the optimal transparency of an exit mirror in a laser

The single-mode approximation and an allowance for the distribution of the field in an open resonator, governed by partial reflection from an opaque mirror, and a Gaussian distribution of the field along the radius are used to find the average gain of a laser and the conditions ensuring the optimal transparency of exit mirrors of different types, and also the maximum output power of a laser, resulting in a considerable refinement of the published results.