title: Femtosecond stimulated Raman spectroscopy using a scanning multichannel technique.
abstract: A scanning multichannel technique (SMT) has been implemented in femtosecond stimulated Raman spectroscopy (FSRS). By combining several FSRS spectra detected at slightly different positions of the spectrograph via SMT, we have eliminated the systematic noise patterns ("fixed  pattern noise") due to the variation in sensitivity and noise characteristics of the individual charge-coupled device (CCD) pixels. In nonresonant FSRS, solvent subtraction can effectively remove the systematic noise pattern even without SMT. However, in the case of resonant FSRS, we  show that a similar solvent subtraction procedure is ineffective at removing the noise patterns without SMT. Application of SMT results in averaged FSRS spectra with improved signal-to-noise ratios that approach the shot-noise limit.
authors.affiliation: Department of Chemistry, University of Rochester, 120 Trustee Rd., Rochester, New York 14627, USA.
authors.forename: J Reddy
authors.initials: JR
authors.lastname: Challa
authors.forename: Yong
authors.initials: Y
authors.lastname: Du
authors.forename: David W
authors.initials: DW
authors.lastname: McCamant