Deconvolution of infrared spectra beyond the Doppler limit

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 (~10(3)) and in which base line variations have been eliminated. Deconvolution of a Doppler-limited spectrum of C(6)H(6) measured on a difference-frequency laser system yielded linewidths of ~1.2 x 10(-3) cm(-1) (compared with the Doppler width of 3.6 x 10(-3) cm(-1) at 203 K). Extensive reliability tests of the deconvolution technique have been performed.