Mid-IR beam direction stabilization scheme for vibrational spectroscopy, including dual-frequency 2DIR

Nyby, Clara; Leger, Joel D.; Tang, Jiacheng; Varner, Clyde; Kireev, Victor V.; Rubtsov, Igor V.

doi:10.1364/oe.22.006801

Cited by 23 publications

(21 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Two pairs of Signal and Idler OPA outputs were directed into two computer-controlled noncollinear difference-frequency generation (DFG) units (nIR-A and nIR-B, Quantronix), which generate mid-IR pulses with energies ranging from 1.5 to 10 μJ, depending on the central wavelength. The 2DIR instrument features separate schematics for stabilizing the directions of both mid-IR beams, 23 a unit to satisfy the phase matching conditions for the mid-IR beam directions at the sample, interferometric delay measurement units with active phase stabilization and phase modulation. The heterodyned signal is measured using a multi-channel MCT array detector (IR-6400, Infrared Associates) attached to a monochromator HORIBA).…”

Section: Dir and Ra 2dir Measurementsmentioning

confidence: 99%

Electron transfer rate modulation in a compact Re(i) donor–acceptor complex

Yue

Grusenmeyer

et al. 2015

Dalton Trans.

Self Cite

View full text Add to dashboard Cite

Formation of the charge transfer state with the rate constant of (10 ps)(-1) has recently been reported for the complex fac-[Re(I)(CO)3(DCEB)(3DMABN)] (ReEBA); where 3DMABN is 3-dimethylaminobenzonitrile, serving as an electron donor, and DCEB is 4,4'-(dicarboxyethyl)-2,2-bipyridine, serving as an electron acceptor (Y. Yue et al., J. Phys. Chem. A, 118, 10407). 3-Pulse UV-pump - IR-pump - IR-probe spectroscopy is used in this work to study how the charge separation reaction in ReEBA to form a ligand to ligand charge transfer state (LLCT) can be modulated by vibrational excitation of various modes of the complex. While no significant rate modulation was found when the cyano group stretching mode of the 3DMABN donor was excited, a sizable effect was found when the ring stretching mode of the DCEB acceptor was excited. The accumulation of the charge separated state (LLCT state) in the 3-pulse experiment was observed as a sharp excited-state vibrational peak of the symmetric stretch of the three facial carbonyl groups, νSS(CO). Modeling indicates that the rate of charge separation is increased by ca. 28% when vibrational excitation is present. The vibronic coupling signal of the bpy ring mode and νSS(CO) as well as the energy transport dynamics from bpy to carbonyl contributed to the 3-pulse signal and was studied as well using the 3-pulse method. Energy transport between the same modes in the ground electronic state was measured by relaxation-assisted two-dimensional infrared (RA 2DIR) spectroscopy. The energy transport times of 4 ± 0.7 and 5 ± 1.5 ps were found for the ground and excited electronic states.

show abstract

Section: Dir and Ra 2dir Measurementsmentioning

confidence: 99%

Electron transfer rate modulation in a compact Re(i) donor–acceptor complex

Yue

Grusenmeyer

et al. 2015

Dalton Trans.

Self Cite

View full text Add to dashboard Cite

show abstract

“…45 Briefly, the laser pulses of 80 fs at 800 nm at 1 kHz repetition rate (Libra, Coherent) were used to pump two OPAs (Palitra, Quantronix) followed by two DFG units. The instrument uses a built-in beam direction stabilization scheme accurate to 50 μrad, 46 closed-loop phase stabilization accurate to 70 as, phase cycling facilitating elimination of the scattered light, and automatic tuning of the BOXCARS phase-matching beam geometry. For 2DIR measurements of nonenhanced films, the pulse energies of the three mid-IR pulses were ca.…”

Section: Methodsmentioning

confidence: 99%

Radiative Enhancement of Linear and Third-Order Vibrational Excitations by an Array of Infrared Plasmonic Antennas

et al. 2018

Self Cite

View full text Add to dashboard Cite

Infrared gold antennas localize enhanced near fields close to the metal surface, when excited at the frequency of their plasmon resonance, and amplify vibrational signals from the nearby molecules. We study the dependence of the signal enhancement on the thickness of a polymer film containing vibrational chromophores, deposited on the antenna array, using linear (FTIR) and third-order femtosecond vibrational spectroscopy (transient absorption and 2DIR). Our results show that for a film thickness beyond only a few nanometers the near-field interaction is not sufficient to account for the magnitude of the observed signal, which nevertheless has a clear Fano line shape, suggesting a radiative origin of the molecule-plasmon interaction. The mutual radiative damping of plasmonic and molecular transitions leads to the spectroscopic signal of a molecular vibrational excitation to be enhanced by up to a factor of 50 in the case of linear spectroscopy and over 2000 in the case of third-order spectroscopy. A qualitative explanation for the observed effect is given by the extended coupled oscillators model, which takes into account both near-field and radiative interactions between the plasmonic and molecular transitions.

show abstract

“…Yet, to date only theoretical studies are available on this topic. 29−31 In this study, we used RA 2DIR spectroscopy 32,33 to measure the temperature dependence of vibrational energy transport through a set of azPEGn compounds featuring chains of n = 0, 2, 4, and 8 PEG units terminated by azido and succinimide ester end groups (Figure 1A). To perform measurements at temperatures ranging from cryogenic to RT (10−295 K), the compounds were imbedded into a polystyrene (PS) matrix (see the Supporting Information for experimental details).…”

mentioning

confidence: 99%

Low-Temperature Vibrational Energy Transport via PEG Chains

Mackin

Leong

Rubtsova

et al. 2020

J. Phys. Chem. Lett.

Self Cite

View full text Add to dashboard Cite

We used relaxation-assisted two-dimensional infrared spectroscopy to study the temperature dependence (10−295 K) of end-to-end energy transport across end-decorated PEG oligomers of various chain lengths. The excess energy was introduced by exciting the azido end-group stretching mode at 2100 cm −1 (tag); the transport was recorded by observing the asymmetric CO stretching mode of the succinimide ester end group at 1740 cm −1 . The overall transport involves diffusive steps at the end groups and a ballistic step through the PEG chain. We found that at lower temperatures the through-chain energy transport became faster, while the end-group diffusive transport time and the tag lifetime increase. The modeling of the transport using a quantum Liouville equation linked the observations to the reduction of decoherence rate and an increase of the mean-free-path for the vibrational wavepacket. The energy transport at the end groups slowed down at low temperatures due to the decreased number and efficiency of the anharmonic energy redistribution pathways.

show abstract

Mid-IR beam direction stabilization scheme for vibrational spectroscopy, including dual-frequency 2DIR

Cited by 23 publications

References 17 publications

Electron transfer rate modulation in a compact Re(i) donor–acceptor complex

Electron transfer rate modulation in a compact Re(i) donor–acceptor complex

Radiative Enhancement of Linear and Third-Order Vibrational Excitations by an Array of Infrared Plasmonic Antennas

Low-Temperature Vibrational Energy Transport via PEG Chains

Contact Info

Product

Resources

About