Single line CO laser operation

Plasma kinetic effects of nitrogen and hydrogen addition to carbon monoxide laser discharges

“…The usefulness of the effective multiline small signal gain (defined as the intensityweighted average of the individual single-line small signal gains) has been discussed previously and confirmed with a single-line laser (Smith and Murray 1981). A probe beam from a multiline low-power oscillator was passed through a 10 mm diameter, 1 m long, water-cooled sealed discharge tube (central cathode and anode at each end) filled with gas mixtures typical of those used in sealed-off cw lasers and the gain determined as described by Murray and Smith (1978).…”

“…The electron density was measured simultaneously with the gain and the discharge voltage in the same discharge tube; hence each set of measurements relates to identical plasma conditions. A microwave cavity (-9.1 GHz) method was used to measure the electron density (Murray and Smith 1981). From the difference in resonant frequency and cavity Q observed when the discharge is on and off the average electron density ne can be determined.…”

“…The positive-ion spectrum of gas mixtures containing nitrogen was investigated using the equipment described by Shields and Smith (1977). The experiment was carried out in a larger diameter discharge tube than used for the gain, electron density and voltage measurements, but the pressure was adjusted to keep the product of tube diameter and pressure equal in both discharges (Murray and Smith 1981). Hence, by the similarity laws of gas discharges, similar E/N, electron densities and mobilities are to be expected in both systems.…”