High resolution infrared diode laser spectroscopy for isotope analysis—Measurement of isotopic carbon monoxide

Abstract

A tunable infrared diode laser spectroscopic system for stable isotope analysis has been developed. The system uses (1) a tunable single mode PbTe/PbEuSeTe diode laser and (2) a sample cell with dual path length matched to the expected order of relative isotopic spectral intensities. Because of the unique features of such a system, isotopic molecules with similar mass and vastly different concentrations can readily be detected and measured. The principle and operation of the system are described, and the relative abundance of isotopic carbon monoxide 12C16O, 12C17O, 12C18O has been measured for the first time by a tunable diode laser system.