New additional cooling effect of diffusion cooled sealed-off CO2 lasers excited by dielectric barrier discharges at about 1 MHz with an all-solid-state generator
✍ Scribed by S. Wieneke; C. Uhrlandt; W. Viöl
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 213 KB
- Volume
- 1
- Category
- Article
- ISSN
- 1612-2011
No coin nor oath required. For personal study only.
✦ Synopsis
Diffusion cooled sealed-off CO~2~ lasers excited by a
dielectric barrier discharge with a developed all-solid-state
generator. A homogeneous discharge of hf excitation at average
electrical power density of up to 25 Wcm^-3^ is obtained
without applying any stabilization techniques on the discharge at
a discharge gap of d = 6 mm for the first time. A discharge gap
of d = 6 mm is used to ensure a free propagation of the laser
beam without any waveguide losses. A maximal output laser power of
70 W is attained with a laser efficiency of 8 % at an electrical
power density of 20 Wcm^-3^. A laser efficiency of 12.5 % is
reached at an electrical input power of 10 Wcm^-3^. Emission
spectroscopy is used to measure the spatially resolved electron
energy in the discharge gap at excitation frequencies between 0.4
and 2.4 MHz. It shows, that the mean electron energy lies in an
efficient range to excite CO~2~ lasers. An optical fibre
thermometer is used to measure the gas temperature porfile inside
the discharge gap. The measured gas temperature is 150 K below the
theoretically calculated value. A additionally cooling effect is
responsible for the low gas temperature.