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

Frequency stabilization of a RF excited CO
2
laser on the peak of the Doppler broadened gain curve using the photoacoustic effect generated from the laser itself is achieved. The photoacoustic signal is directly coupled from a RF discharge chamber using a condenser microphone into an amplifier and a lock-in stabilizer. The frequency stability is estimated to be better then 3×10
⁻⁸
.