Abstract

Broadband (500-cm^–1) infrared pulses of 350-fs duration tunable from 2.5 to 5.5 µm have been produced by difference frequency mixing in LiIO₃ and used to do subpicosecond time-resolved vibrational spectroscopy.¹ Using a synchronized visible pump beam, time-resolved infrared absorption of transient species can be recorded. When the transmitted infrared probe pulses are monitored through a monochromator, vibrational absorption dynamics can be monitored with transform-limited resolution. Evolution of the vibrational spectra of heme proteins after photoexcitation has been studied.

© 1989 Optical Society of America