Fluctuations of the polarization state of CO2 laser radiation

Observations are reported of fluctuations in the polarization state of radiation from a CO₂ laser having an unstable resonator without selective elements. A connection is established between such fluctuations and changes in the spectral composition of the radiation during lasing. A demonstration is given of the influence of the effects discovered on the penetration of laser radiation into long metal channels which can be manifested in deep-penetration laser welding.