Two-Stage Radio Frequency Power Generator-Amplifier Design for a TEM00 CO2 Slab Waveguide Laser

ABSTRACT

This letter presents the results of the research conducted on the design, construction and test of a two stage radio frequency power generator-amplifier directed adapted to an in-house-built compact CO2 waveguide laser. The main characteristic of this power supply lies in the fact its design is based on MOSFET technology for both the oscillator and the amplifier stages. RF output power is centered at 81MHz frequency signal between 100W to 150W. The two-stage system device has a minimum electric conversion efficiency of 64%. Consequently, the laser head and RF excitation design must have an electrical termination of 50􀀁 impedance and the whole system may include a proper matching circuit. The overall test, for the entire system: RF excitation along with our CO2 laser head, is made with a typical gas mixture of CO2- N2-He with proportion of 1:1:3 correspondingly and at a final pressure of 40Torr. Under these specific conditions, a maximum optical output power of 10.7W was obtained for an input feed RF power of 147W. Regarding the optical quality we measured the transverse mode of propagation TEM00 which indicate the entire system work very near the diffraction limit specifications for similar laser systems.