TY - JOUR
T1 - Single-pulse coherently controlled nonlinear Raman spectroscopy and microscopy
AU - Dudovich, Nirit
AU - Oron, Dan
AU - Silberberg, Yaron
N1 - Funding Information:
supported by the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Philips Research and partly supported by the Brite Euram project Tunnel Sense.
Funding Information:
We thank D. Mandelik for his aid in preparing the microscope samples. Financial support by the Israeli Science Foundation and by the Bundesministerium fur Bildung und Forschung is gratefully acknowledged.
PY - 2002/8/1
Y1 - 2002/8/1
N2 - Molecular vibrations have oscillation periods that reflect the molecular structure, and are hence being used as a spectroscopic fingerprint for detection and identification. At present, all nonlinear spectroscopy schemes use two or more laser beams to measure such vibrations. The availability of ultrashort (femtosecond) optical pulses with durations shorter than typical molecular vibration periods has enabled the coherent excitation of molecular vibrations using a single pulse. Here we perform single-pulse vibrational spectroscopy on several molecules in the liquid phase, where both the excitation and the readout processes are performed by the same pulse. The main difficulty with single-pulse spectroscopy is that all vibrational levels with energies within the pulse bandwidth are excited. We achieve high spectral resolution, nearly two orders of magnitude better than the pulse bandwidth, by using quantum coherent control techniques. By appropriately modulating the spectral phase of the pulse we are able to exploit the quantum interference between multiple paths to selectively populate a given vibrational level, and to probe this population using the same pulse. This scheme, using a single broadband laser source, is particularly attractive for nonlinear microscopy applications, as we demonstrate by constructing a coherent anti-Stokes Raman (CARS) microscope operating with a single laser beam.
AB - Molecular vibrations have oscillation periods that reflect the molecular structure, and are hence being used as a spectroscopic fingerprint for detection and identification. At present, all nonlinear spectroscopy schemes use two or more laser beams to measure such vibrations. The availability of ultrashort (femtosecond) optical pulses with durations shorter than typical molecular vibration periods has enabled the coherent excitation of molecular vibrations using a single pulse. Here we perform single-pulse vibrational spectroscopy on several molecules in the liquid phase, where both the excitation and the readout processes are performed by the same pulse. The main difficulty with single-pulse spectroscopy is that all vibrational levels with energies within the pulse bandwidth are excited. We achieve high spectral resolution, nearly two orders of magnitude better than the pulse bandwidth, by using quantum coherent control techniques. By appropriately modulating the spectral phase of the pulse we are able to exploit the quantum interference between multiple paths to selectively populate a given vibrational level, and to probe this population using the same pulse. This scheme, using a single broadband laser source, is particularly attractive for nonlinear microscopy applications, as we demonstrate by constructing a coherent anti-Stokes Raman (CARS) microscope operating with a single laser beam.
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U2 - 10.1038/nature00933
DO - 10.1038/nature00933
M3 - Article
C2 - 12152073
AN - SCOPUS:0036682132
VL - 418
SP - 512
EP - 514
JO - Nature
JF - Nature
SN - 0028-0836
IS - 6897
ER -