It is shown that the deconvolution method of Van Cittert can be used reliably to enhance the effective spectral resolution by a factor of ~3 with data that exhibit a high SNR (~103) and in which base line variations have been eliminated. Deconvolution of a Doppler-limited spectrum of C6H6 measured on a difference-frequency laser system yielded linewidths of ~1.2 × 10-3 cm-1 (compared with the Doppler width of 3.6 × 10-3 cm-1 at 203 K). Extensive reliability tests of the deconvolution technique have been performed.
J. Pliva, A. S. Pine, and P. D. Willson, "Deconvolution of infrared spectra beyond the Doppler limit," Appl. Opt. 19, 1833-1837 (1980)