Laser FM spectroscopy with photochemical modulation - A sensitive, high resolution technique for chemical intermediates

We have combined the techniques of frequency-modulation spectroscopy (FMS) and photochemical-modulation spectroscopy to carry out high-resolution, high-sensitivity absorption measurements on the formyl and amino radicals. Using the (0,90, 0)-(0,01, 0) band of the Ã,2A″- {Mathematical expression},2A′ transition of HCO at 614 nm, we obtained a sensitivity limit for absorption of 1.5×10-6. Reconstructed spectra of several HCO lines are presented. © 1984 Springer-Verlag.