A simple probing method for obtaining broadband multichannel infrared spectra with picosecond or higher time resolution is described. Spectrally broad infrared pulses are produced by difference frequency mixing in LiIO3 between the second harmonic of a Nd+3: YAG laser and the broadband output of a synchronously pumped dye laser. After sample absorption the infrared pulse is upconverted by a second LiIO3 crystal, which yields a visible pulse that is dispersed on a multichannel vidicon detector to obtain transient spectra of 4-cm−1 FWHM resolution.
© 1989 Optical Society of America
Original Manuscript: December 7, 1988
Manuscript Accepted: March 16, 1989
Published: June 1, 1989
E. J. Heilweil, "Ultrashort-pulse multichannel infrared spectroscopy using broadband frequency conversion in LiIO3," Opt. Lett. 14, 551-553 (1989)