Abstract:
An investigation was made of the spatial structure of the output radiation from static waveguide CO2 lasers excited by a transverse rf field of 120 MHz frequency. The specific input energy was ~2 W/cm. Measurements were made on circular waveguides having radii of 0.8–1.5 mm fabricated of BeO ceramic and glass and on a metal ceramic waveguide (Al + BeO) having a 2 × 2 mm cross section. It was established that in lasers with BeO waveguides and plane-plane resonators lasing is achieved in the HE11 mode or in a superposition of the TE01 and HE21 modes. The lasing power in the HE11 mode was 1.42 times higher than that in the superposed modes. The laser with the square waveguide emitted hybrid HEnm modes. A homogeneous distribution of the unsaturated gain over the cross section of the transverse rf discharge promoted excitation of higher-order modes.