Polarized maser growth

A polarized maser is assumed to operate in an anisotropic medium with natural modes polarized differently to the maser. It is shown that when the spatial growth rate and the generalized Faraday rotation rate are comparable, the polarization of the growing radiation is different from those of the maser and medium. In particular, for a lineary polarized maser operating in a medium with linearly polarized natural modes. the growing radiation is partially circularly polarized. This provides a previously unrecognized source of circular polarization that may be relevant to pulsar radio emission.