Investigation of the spectral content of a cw CO laser output using a high-resolution scanning Fabry-Perot interferometer

• Published in: Optics and laser technology Vol. 8; no. 5; pp. 221 - 226
• Main Authors: Dennis, R.B., Mackenzie, H.A., McClelland, G., Hamza, F.H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.1976
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/0030-3992(76)90006-2

The use of a scanning Fabry-Perot interferometer of variable length (variable resolution) for investigating the output of a cw CO laser is reported. Under experimental conditions required to achieve maximum power it was found that the laser output consisted of two or more simultaneously occuring transitions due to the overlapping nature of the vibration- rotation bands. The frequency differences between these transitions were measured to an accuracy of ≲ 0.01 cm -1. Operation of the CO laser on a single vibration-rotation transition was obtained by controlling the laser gain with the experimental variables of discharge pressure, gas temperature, and optical alignment. An alternative approach of obtaining monochromatic radiation, by using a Fabry-Perot interferometer as a frequency selective filter external to the CO laser, is reported.