ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A picosecond time-resolved multiplex coherent anti-Stokes Raman scattering (CARS) spectrometer based on a new principle has been constructed using a femtosecond laser, nanosecond lasers, and a streak camera. The second harmonic of the output from the femtosecond Ti:sapphire oscillator/regenerative-amplifier system is used for the photoexcitation. The second harmonic of a nanosecond Nd:YLF laser is used as CARS probing ω1 radiation, and the output of a nanosecond broadband dye laser is used as ω2 radiation. CARS signals, which are generated from the sample during the nanosecond probing pulses, are analyzed in the frequency domain by a spectrograph and are resolved in the time domain by a streak camera. This enables us multiplex CARS measurements not only in the frequency domain but also in the time domain (termed two-dimensional multiplex CARS). Consequently, CARS spectra at various delay times are obtainable with a single measurement. Owing to the short duration and high stability of the femtosecond pumping pulses, time resolution as high as 15 ps has been achieved. Picosecond time-resolved CARS spectra of all-trans retinal and β-carotene are presented to demonstrate the high capability of the constructed system. The factors which determine the time resolution of this CARS spectrometer are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1145204
