Frequency stabilization of a radio frequency excited CO2 laser using the photoacoustic effect

A frequency and a power of rf excited CO(2) laser are stabilized using the photoacoustic effect generated from the laser itself. As the radiation intensity in a laser resonator changed, the pressure of laser medium gas changed due to its photoacoustic effect. A condenser microphone built in the resonator is used to convert delicate variations in the pressure into voltage signals to be used as input signals for lock-in stabilizer. As a result of stabilizing the frequency and power of the laser oscillated from P(20) line, at the apex of gain curve, the relative stability of the optical frequency and the rate of change in laser power are 5.57 x 10(-8) and 9.3%, respectively.