Frequency-switching waveguide CO2 laser for atmospheric pollution monitoring

A waveguide CO₂ laser with switching between any two neighboring vibrational–rotational transitions was developed. The transitions were selected with a diffraction grating and the switching of lasing at frequencies up to 600 Hz was produced by modulation of the resonator length. Use of the synchronous detection method made it possible to record a 10^–2 % unbalance between the laser powers at the two emission frequencies. An analysis was made of the possibility of using this laser in various atmospheric pollution monitoring methods.