Optically Calibrated Infrared High Pressure Cell

Abstract

A high pressure optical cell of large aperture has been constructed for use in pressure broadening studies of gases in the infrared region of the spectrum. The cell is tight at both vacuum and 1000 psi and is constructed of stainless steel with 3×1-in. calcium fluoride windows. A method of measuring short path length cell spacing to an accuracy of 1% using an optical “butterfly” is described. Data are presented on the pressure-induced distortion of the cell path length for calcium fluoride windows as well as optical glass windows.