Electron-radiation temperature measurements in a sealed-off CO2laser system
- Resource Type
- Periodical
- Authors
- Polman, J.; Witteman, W.
- Source
- IEEE Journal of Quantum Electronics IEEE J. Quantum Electron. Quantum Electronics, IEEE Journal of. 6(3):154-157 Mar, 1970
- Subject
- Engineered Materials, Dielectrics and Plasmas
Photonics and Electrooptics
Temperature measurement
Laser noise
Noise measurement
Gas lasers
Temperature dependence
Probes
Electrons
Vibration control
Laser excitation
- Language
- ISSN
- 0018-9197
1558-1713
Measurements of the noise temperature in theLband were used to investigate the effect of several constituents of the gas mixture on the discharge properties of the CO 2 laser. Addition of He and H 2 O to the discharge gives no significant change in the temperature. By contrast, addition of 4-torr N 2 to 2-torr CO 2 increases the noise temperature from 1.3 to 1.5 eV. Increase of the current in an optimum CO 2 -N 2 -He-H 2 O mixture leaves the temperature nearly constant (1.5 eV). This result deviates from that of Tyte and Sage, who found an anomalous rise of noise temperature with increasing current. Within the 5 percent experimental error the radiation temperature does not depend on laser action. A comparison of the present results with those of probe measurements is given. It is concluded that He has practically no influence on the average electron energy, which in turn controls the vibrational excitation. This and the observed behavior of the output power as a function of the partial He pressure give strong evidence that the major role played by He is cooling the gas in the discharge.