title: Accurate convergence of transient-absorption spectra using pulsed lasers.
abstract: Transient-absorption spectroscopy is a common and well-developed technique for measuring time-dependent optical phenomena. One important aspect, especially for measurements using pulsed lasers, is how to average multiple data acquisition events. Here, we use a mathematical analysis method based on covariance to evaluate various averaging schemes. The analysis reveals that the baseline and the signal converge to incorrect values without balanced detection of the probe, shot-by-shot detection, and a specific method of averaging. Experiments performed with sub-7 fs pulses confirm the analytic results and reveal insights into molecular excited-state vibrational dynamics.
authors.affiliation: Department of Chemistry, New York University, New York, New York 10003, USA.
authors.forename: Johanna
authors.initials: J
authors.lastname: Brazard
authors.affiliation: Department of Chemistry, New York University, New York, New York 10003, USA.
authors.forename: Laurie A
authors.initials: LA
authors.lastname: Bizimana
authors.affiliation: Department of Chemistry, New York University, New York, New York 10003, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Turner