Principles and Applications of Broadband Impulsive Vibrational Spectroscopy

Liebel, Matz; Schnedermann, Christoph; Wende, Torsten; Kukura, Philipp

doi:10.1021/acs.jpca.5b05948

Cited by 132 publications

(178 citation statements)

References 67 publications

Supporting

Mentioning

173

Contrasting

Order By: Relevance

“…Increasing the integration window to ±250 fs only results in, at the signal-to-noise levels of our trueSMS scans, cosmetic improvement over the ±32 fs spectrum. Importantly, these observations are not a result of zero-padding which has no effect on the resolvability or information content of spectral data 45 .…”

Section: B) Wigner Representation and Light-matter Interactionsmentioning

confidence: 91%

Room-temperature ultrafast nonlinear spectroscopy of a single molecule

2017

View full text Add to dashboard Cite

Single molecule spectroscopy aims at unveiling often hidden but potentially very important contributions of single entities to a system's ensemble response. Albeit contributing tremendously to our ever growing understanding of molecular processes the fundamental question of temporal evolution, or change, has thus far been inaccessible, resulting in a static picture of a dynamic world. Here, we finally resolve this dilemma by performing the first ultrafast time-resolved transient spectroscopy on a single molecule. By tracing the femtosecond evolution of excited electronic state spectra of single molecules over hundreds of nanometres of bandwidth at room temperature we reveal their non-linear ultrafast response in an effective 3-pulse scheme with fluorescence detection. A first excitation pulse is followed by a phase-locked de-excitation pulse-pair, providing spectral encoding with 25 fs temporal resolution. This experimental realisation of true single molecule transient spectroscopy demonstrates that two-dimensional electronic spectroscopy of single molecules is experimentally in reach.Our fundamental understanding of key processes such as vision, light harvesting, singlet fission or the effect of coherences on molecular reactivity has dramatically benefited from the advent of non-linear ultrafast measurement techniques 1-4 . The convenient way to study these processes is transient absorption, or pump-probe, spectroscopy 5 . Here, a temporally short laser pulse photo-excites the system of interest and a time-delayed probe pulse reports on the spectro-temporal evolution on the excited electronic state of interest ( Figure 1). Such experiments are routinely performed on molecular ensembles and sufficiently high signal levels are ensured by adjusting the molecular concentration within the probe volume. If one were to perform such an experiment on a single molecule, the sole optimization possibility is the reduction of the probe volume down to the diffraction limit. As a result, the illuminated area (S) at ambient temperature is, even in the ideal case, six orders of magnitude larger than a typical molecular absorption cross section () or, in other words, only one in 10 6 photons is absorbed by the single molecule thus resulting in a signal-to-background ratio of less than 10 -6 ( Figure 1). Given these considerations it is not surprising that even the comparatively easy task of detecting a single molecule in linear absorption has only been achieved recently and under great experimental efforts 6-8 . More challenging pump-probe experiments in resonance with a stimulated emission transition have so far, amid showing promising results, remained unsuccessful 9 . Under cryogenic conditions the absorption cross section increases dramatically but the dramatic reduction in homogeneous linewidth results in the loss of all dynamical information on femtosecond timescales 10,11 . In summary the only feasible possibility to resolve ultrafast transient dynamics of a

show abstract

Section: B) Wigner Representation and Light-matter Interactionsmentioning

confidence: 91%

Room-temperature ultrafast nonlinear spectroscopy of a single molecule

2017

View full text Add to dashboard Cite

show abstract

“…Time traces at single detection wavelengths are either Fourier transformed, or fitted with damped cosines. 1,2,4,25,27,41,47 Next, for a few dominant frequencies the amplitude and phase can be plotted as function of the detection wavelength. No attempt has been made yet to globally analyze the complete data.…”

Section: Introductionmentioning

confidence: 99%

Estimation of damped oscillation associated spectra from ultrafast transient absorption spectra

Stokkum

Jumper

Snellenburg

et al. 2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

When exciting a complex molecular system with a short optical pulse, all chromophores present in the system can be excited. The resulting superposition of electronically and vibrationally excited states evolves in time, which is monitored with transient absorption spectroscopy. We present a methodology to resolve simultaneously the contributions of the different electronically and vibrationally excited states from the complete data. The evolution of the excited states is described with a superposition of damped oscillations. The amplitude of a damped oscillation cos(ωnt)exp(−γnt) as a function of the detection wavelength constitutes a damped oscillation associated spectrum DOASn(λ) with an accompanying phase characteristic φn(λ). In a case study, the cryptophyte photosynthetic antenna complex PC612 which contains eight bilin chromophores was excited by a broadband optical pulse. Difference absorption spectra from 525 to 715 nm were measured until 1 ns. The population dynamics is described by four lifetimes, with interchromophore equilibration in 0.8 and 7.5 ps. We have resolved 24 DOAS with frequencies between 130 and 1649 cm−1 and with damping rates between 0.9 and 12 ps−1. In addition, 11 more DOAS with faster damping rates were necessary to describe the “coherent artefact.” The DOAS contains both ground and excited state features. Their interpretation is aided by DOAS analysis of simulated transient absorption signals resulting from stimulated emission and ground state bleach.

show abstract

“…Reducing the pulse duration to 10 fs would enhance the effective time resolution of the experiment from currently 27 fs to 14 fs. For a 1000 cm −1 mode, this would increase the corresponding Fourier intensity 30-fold while a 2000-fold increase is expected for a 1500 cm −1 mode30. Furthermore, the efficiency of generating vibrational coherences is improved for shorter pulse durations due to the enhanced bandwidth, leading to an additional increase in signal magnitude30.…”

Section: Resultsmentioning

confidence: 99%

“…1c). Following Fourier transformation, a background- and baseline-free Raman spectrum is obtained2324252627282930. A particularly powerful time-domain approach was recently demonstrated based on two synchronized frequency combs, enabling extremely rapid spectral acquisition, but at the expense of drastically lowering the duty cycle31.…”

mentioning

confidence: 99%

Wide-Field Detected Fourier Transform CARS Microscopy

Duarte

Schnedermann

Kukura

2016

Sci Rep

View full text Add to dashboard Cite

We present a wide-field imaging implementation of Fourier transform coherent anti-Stokes Raman scattering (wide-field detected FT-CARS) microscopy capable of acquiring high-contrast label-free but chemically specific images over the full vibrational ‘fingerprint’ region, suitable for a large field of view. Rapid resonant mechanical scanning of the illumination beam coupled with highly sensitive, camera-based detection of the CARS signal allows for fast and direct hyperspectral wide-field image acquisition, while minimizing sample damage. Intrinsic to FT-CARS microscopy, the ability to control the range of time-delays between pump and probe pulses allows for fine tuning of spectral resolution, bandwidth and imaging speed while maintaining full duty cycle. We outline the basic principles of wide-field detected FT-CARS microscopy and demonstrate how it can be used as a sensitive optical probe for chemically specific Raman imaging.

show abstract

Principles and Applications of Broadband Impulsive Vibrational Spectroscopy

Cited by 132 publications

References 67 publications

Room-temperature ultrafast nonlinear spectroscopy of a single molecule

Room-temperature ultrafast nonlinear spectroscopy of a single molecule

Estimation of damped oscillation associated spectra from ultrafast transient absorption spectra

Wide-Field Detected Fourier Transform CARS Microscopy

Contact Info

Product

Resources

About