title: Acquisition of mid-infrared spectra from nonrepeatable events with sub-100-micros temporal resolution using planar array infrared spectroscopy.
abstract: A novel method is presented that is capable of collecting time-resolved vibrational spectroscopic information with sub-100-micros temporal resolution. Unlike previous step scan FT-IR approaches, the phenomena under study do not necessarily need to be repeatable. The methodology described herein is based on the planar array infrared (PA-IR) technique, which utilizes a spectrograph for wavelength dispersion and a mid-infrared focal plane array (FPA) detector for simultaneous detection of multiple wavelengths. Unlike previous PA-IR approaches, a rolling mode FPA is employed. This unique data readout mode, where data are read out of the array two rows at a time, is exploited to generate increased temporal resolution. The capabilities of this technique are demonstrated using the example of the electric field-induced Freedericksz transition of a nematic liquid crystal. It is shown that the orientational dynamics of a single transition can be tracked over a spectral range of 154 cm(-)(1) with a temporal resolution of 99.17 micros while requiring a total experimental time of less than 1 s.
authors.affiliation: Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA. snively@che.udel.edu
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Snively
authors.forename: Christian
authors.initials: C
authors.lastname: Pellerin
authors.forename: John F
authors.initials: JF
authors.lastname: Rabolt
authors.forename: D Bruce
authors.initials: DB
authors.lastname: Chase