Asymptotic Analysis of Confocal Unstable Resonators

For optimum designing of an unstable resonator to suit the properties of a specified gain medium, computer code to analyze unstable resonators has been developed. Some important consideration in designing them and mode separation aspects in frequency domain are shown in the case of strip resonators and of resonators in which there is arbitrary slowly varying spatial dependence of the gain. The asymptotic theory of resonators is used to analyze them. It yields higher loss modes as well as the lowest loss mode.