A Novel Laser Heterodyne Technique for the Measurement of Electron Density in Gas Discharges: Application to a TEA CO2 Laser Plasma

We describe a novel intracavity laser heterodyne technique for the measurement of electron density in gas discharges. The method produces time-resolved data from a single pulse and we have used it to monitor electron densities in a TEA laser discharge with a typical CO2 laser gas mixture. Good agreement was found between the measured electron density and its value calculated from current density and drift velocity. A maximum value of 5 × 1013 cm-3 was observed.