Graded Reflectivity Mirror Research Articles

Propagation of super-Gaussian field distributions

The near- and far-field propagation of initially super-Gaussian field distributions is discussed. upon propagation, the beam profile is shown to undergo distortions of a magnitude which increases with the super-Gaussian order. These distortions can lead to a significant increase of the on-axis intensity in the near-field. The beam quality, evaluated both in terms of the beam parameter product and theM 2 factor, is shown to decrease as the super-Gaussian order gets larger. These calculations also illustrate the difficulties associated with theM 2 factor when characterizing the propagation of a beam with increasingly sharp edges. The effect of the transmission of the super-Gaussian field through a super-Gaussian graded-reflectivity mirror (GRM) is also discussed. The results of this study have direct implication in the domain of GRM resonator design.

Variable reflectivity unstable resonators for coherent laser radar emitters

Beam properties obtained from a TE CO(2) laser in a Cassegrain resonator using various graded reflectivity mirror couplers are compared. It is shown that, experimentally, Gaussian profiles maximize the far-field intensity while parabolic profiles yield more uniform near fields with a lower energy extraction. Both configurations appear suited for coherent ladar systems.