Title :
A new helical coupling microwave antenna excited high-power CO2 laser using a cylindrical resonant cavity
Author :
Ikeda, Tetsuya ; Danno, Minoru ; Monaka, Toshiaki ; Noda, Matsuhei ; Tanaka, Jiro
Author_Institution :
Adv. Technol. Res. Center, Mitsubishi Heavy Ind. Ltd., Yokohama, Japan
fDate :
5/1/1999 12:00:00 AM
Abstract :
A new helical coupling antenna which was installed into a cylindrical microwave cavity (2.45 GHz) has been investigated to obtain high-power CO2 laser operation. Laser experiments using a system of swirling fast axial gas flow parallel to the beam have been performed. The geometric properties of the helical antenna and the gas flow structures were optimized by using numerical codes analyzing the electric fields and gas flow dynamics. The swirling flow of the laser gas mixtures of CO2-N2-He=0.7-5-19 was caused in the discharge tube by an 8-slit nozzle. It is shown that the electric field obtained by the proper design of the helical coupling coil yields homogeneous discharges. The maximum output power and the efficiency (RF to laser power conversion ratio) was obtained as 1010 W and 15%, respectively, at a gas pressure of 45 torr and a gas flow rate of 57 kg/h
Keywords :
carbon compounds; gas lasers; gas mixtures; laser cavity resonators; microwave antennas; 1010 W; 2.45 GHz; 45 torr; 8-slit nozzle; CO2; CO2-N2-He; cylindrical microwave cavity; cylindrical resonant cavity; discharge tube; electric fields; gas flow dynamics; gas flow structures; geometric properties; helical antenna; helical coupling coil; helical coupling microwave antenna; high-power CO2 laser; high-power CO2 laser operation; homogeneous discharges; laser gas mixtures; laser power conversion ratio; maximum output power; numerical codes; swirling fast axial gas flow; Coils; Electron tubes; Fluid flow; Gas lasers; Helical antennas; Laser beams; Laser excitation; Masers; Microwave antennas; Optical coupling;
Journal_Title :
Quantum Electronics, IEEE Journal of
