title: ULTRA: A Unique Instrument for Time-Resolved Spectroscopy.
abstract: We report the development of a high-sensitivity time-resolved infrared and Raman spectrometer with exceptional experimental flexibility based on a 10-kHz synchronized dual-arm femtosecond and picosecond laser system. Ultrafast high-average-power titanium sapphire lasers and optical parametric amplifiers provide wavelength tuning from the ultraviolet (UV) to the mid-infrared region. Customized silicon, indium gallium arsenide, and mercury cadmium telluride linear array detectors are provided to monitor the probe laser intensity in the UV to mid-infrared wavelength range capable of measuring changes in sample absorbance of ΔOD ~ 10(-5) in 1 second. The system performance is demonstrated for the time-resolved infrared, two-dimensional (2D) infrared, and femtosecond stimulated Raman spectroscopy techniques with organometallic intermediates, organic excited states, and the dynamics of the tertiary structure of DNA.
authors.affiliation: Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX, UK. Greg.Greetham@stfc.ac.uk
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Greetham
authors.forename: Pierre
authors.initials: P
authors.lastname: Burgos
authors.forename: Qian
authors.initials: Q
authors.lastname: Cao
authors.forename: Ian P
authors.initials: IP
authors.lastname: Clark
authors.forename: Peter S
authors.initials: PS
authors.lastname: Codd
authors.forename: Richard C
authors.initials: RC
authors.lastname: Farrow
authors.forename: Michael W
authors.initials: MW
authors.lastname: George
authors.forename: Moschos
authors.initials: M
authors.lastname: Kogimtzis
authors.forename: Pavel
authors.initials: P
authors.lastname: Matousek
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Parker
authors.forename: Mark R
authors.initials: MR
authors.lastname: Pollard
authors.forename: David A
authors.initials: DA
authors.lastname: Robinson
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Xin
authors.forename: Michael
authors.initials: M
authors.lastname: Towrie