Continuously-Tunable High-Repetition Rate RF-Excited CO2 Waveguide Laser,
Abstract
The concept of pumping a CO2 laser with a radiofrequency discharge at multiatmospheric pressures in order to obtain continuous frequency tuning has been investigated both theoretically and experimentally. Experimentally 40.68 MHz rf-excitation of discharges between parallel plate electrodes with up to 7-8 kW peak rf-power has been investigated. Emphasis has been laid on how to attain a stable glow-discharge with sufficiently long duration before arcing for integration of enough rf-power in the discharge to reach threshold for laser oscillation. A 10 atm rf-excited CO2 waveguide laser has been developed. With no dispersive elements in the laser resonator and with a 2% output coupler, input rf-power threshold for laser oscillation was 2 kW at 10 atm. Peak output power was 1.5 kW for 7-8 kW input rf-power. The output pulse has the form of a 300 ns duration gain-switched pulse followed by a tail at lower power. An efficiency (input rf-energy/laser output-energy) of 2% has been measured for the gain-switched pulse. The laser has been operated with pulse repetition rates in excess of 1 kHz, limited primarily by the available gas-flow capacity. Continuous frequency tuning between the R(12) and R(14) lines in the 10.4-micrometer band has been demonstrated. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1982
- Accession Number
- ADA118877
Entities
People
- Stian Loevold
Organizations
- Norwegian Defence Research Establishment