To excite plasma in the core of a hollow fiber, a scheme similar to a slot antenna in the wall of a metal microwave waveguide was proposed and implemented. An analytical estimate of the magnitude of the electric field in the slot region where the fiber with a hollow core is placed has been obtained. Using the proposed scheme, the possibility of maintaining argon plasma in the core of a hollow fiber with a diameter as small as 110 μm was demonstrated. The total length of plasma column in the hollow-core fiber was up to 25 cm at Ar pressure ~10 Torr. The frequency of microwave radiation used was 2.4 GHz, the average generated power was below 20 W. The obtained luminescence spectra of argon plasma in the fiber core showed that the argon luminescence in our experiments was observed only in the form of radiation from neutral atoms. The results obtained show that the microwave slot antenna is a promising pumping scheme for gas-discharge fiber lasers based on hollow-core fibers.
Performance of a planar cw C02-laser excited by RF waves at two fixed frequencies of 40 and 125 MHz is studied. A laser output power of 1 00 W and efficiency about 1 0% have been achieved, and the influence of the excitation frequency has been studied. The hybrid waveguide-unstable optical resonators were used in the planar laser.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.