Abstract
CO laser provides several hundreds lines in the wavelength range of 5 to 8 μm with moderate power. It has been applied to laser spectroscopy and photoacoustic detection of trace gases. In the part, the most accurate frequency stabilization methode is the optogalvanic Lamb-dip stabilization using a DC discharge of low pressure CO：N2：Xe mixture inside the laser cavity. In this thesis, we investigate the feasibility of RF optogalvanic Lamb-dip stabilization of CO laser. A RF Colpitts oscillator with a pentode 6AQ5A is used for the study of the CO optogalvanic effect. The RF power of this oscillator is enough to sustain the CO discharge at pressure lower than 1 torr. By using this oscillator, the radio frequency optogalvanic signal is observed with the gas mixture CO：N2：Ar=1：1：60. Under the discharge pressure lower than 700 mtorr, the Doppler-free optogalvanic Lamb dip is detected at the vibrational levels ν=8 to 11 (5.3 to 5.6 μm). Using the first devirative of Lamb dip signal, the frequency stability better than 4 ×10-9 is expected based on the observed signal-to-noise ratio.