Spectral characteristics of an LiNbO3 infrared radiation converter

An investigation was made of the spectral characteristics of an LiNbO₃ crystal which converted infrared radiation to the visible range by summing the infrared and ruby (pump) Irser frequf icies. The dependences of the spectral width of the conversion band on the pump line width and on the angle of divergence of the infrared radiation in the crystal were determined experimentally. The results were compared with theoretical estimates.