Measuring optically thick molecular samples using chirped laser dispersion spectroscopy.

In this Letter, a dispersion-based gas sensing method applied to detection of optically thick samples is presented. We show that chirped laser dispersion spectroscopy (CLaDS) technique provides perfectly linear signal response over a wide range of target analyte concentrations. Using the most convenient chirp-modulated CLaDS detection scheme, it enables spectroscopic measurements in a line-locked mode from the minimum detection limit up to >99% peak molecular absorption.