Profiles of infrared lines of potassium vapor under multiphoton resonance excitation conditions

An investigation was made of the infrared emission spectra of potassium vapor illuminated with giant ruby laser pulses and with the Stokes component of the stimulated Raman scattering of these pulses in nitrobenzene. These emission spectra were recorded after conversion to visible light in a nonlinear crystal. It was found that the dependences of the intensities, widths, and shifts of the infrared lines on the vapor pressure of potassium had extrema. The broadening and shift were induced by the field. The results obtained indicated a considerable importance of six-photon parametric processes in the emission of infrared potassium lines.