Time-resolved infrared spectral photography

Bethune, Donald S.; Lankard, J. R.; Sorokin, P. P.

doi:10.1364/ol.4.000103

Cited by 30 publications

(3 citation statements)

References 6 publications

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“…This is a direct analogue of the IR/visible setup commonly used to monitor vibrational coherences [16,17]. Time-domain SFG is routinely performed in the optical or infrared (IR) regime, most common in IR SFG from molecules on surfaces [18,19]. A visible/UV pulse first brings the molecule into a superposition of electronic ground state and excited states, which is then probed by a broadband hard X-ray pulse after a delay T .…”

Section: Ultrafast Sum-frequency X-ray Diffractionmentioning

confidence: 99%

X-Ray Sum Frequency Diffraction for Direct Imaging of Ultrafast Electron Dynamics

et al. 2018

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X-ray diffraction from molecules in the ground state produces an image of their charge density, and time-resolved x-ray diffraction can thus monitor the motion of the nuclei. However, the density change of excited valence electrons upon optical excitation can barely be monitored with regular diffraction techniques due to the overwhelming background contribution of the core electrons. We present a nonlinear x-ray technique made possible by novel free electron laser sources, which provides a spatial electron density image of valence electron excitations. The technique, sum frequency generation carried out with a visible pump and a broadband x-ray diffraction pulse, yields snapshots of the transition charge densities, which represent the electron density variations upon optical excitation. The technique is illustrated by ab initio simulations of transition charge density imaging for the optically induced electronic dynamics in a donor or acceptor substituted stilbene.

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Section: Ultrafast Sum-frequency X-ray Diffractionmentioning

confidence: 99%

X-Ray Sum Frequency Diffraction for Direct Imaging of Ultrafast Electron Dynamics

et al. 2018

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“…Moreover, the same method can be used to convert laser pulses from far infrared to near infrared, thereby making their detection much more eff icient. This idea was anticipated by the time-resolved infrared spectral photography of Bethune et al 21 We imagine building an infrared spectrometer that utilizes molecular modulation to generate far-infrared radiation, sends that radiation through the test medium, and then converts it back into more easily detectable radiation through the same molecular system.…”

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confidence: 99%

Optical frequency conversion by a rotating molecular wave plate

et al. 2001

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We demonstrate efficient four-wave mixing in low-pressure molecular deuterium without the need for phase matching. We use two laser fields with opposite circular polarizations to produce a strong excitation of a rovibrational transition at a frequency of 3167 cm(-1) . The coherent molecular motion, in turn, modulates a third laser field (also circularly polarized) and results in highly efficient single-sideband conversion.

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“…Examples are the reactions of metal carbonyls111 and an excited singlet of methylene112 as well as laser-initiated explosions in the gas phase. [113][114][115] Picosecond resonance Raman spectra have been reported for the photoproducts of bacteriorhodopsin116,117 and rhodopsin,28 indicating that a retinal conformational change has already taken place within picoseconds. The resonance Raman spectrum of the triplet excited state of oil-irons-retinal118 shows evidence for increased 7r-electron delocalization as compared with the ground state and indicates the possibility of an all-trans or 9-cis configuration.…”

Section: Additional Applicationsmentioning

confidence: 99%