Use of conical mirrors in laser devices

The geometric-optics approach is used to derive an analytic relationship between the angles of divergence of reference radiation and of radiation transmitted by a system of conical mirrors (axicon). The results indicate that the divergence of the axicon-transmitted radiation is anisotropic and the angular distribution is wider. The problem of propagation of radiation in an axicon is shown to be three-dimensional. A brief discussion is given of the influence of intracavity conical surfaces on the properties of a resonator.