Electronic structure of liquid water from polarization-dependent two-photon absorption spectroscopy

Elles, Christopher G.; Rivera, Christopher A.; Zhang, Yuyuan; Pieniazek, Piotr A.; Bradforth, Stephen E.

doi:10.1063/1.3078336

Cited by 65 publications

(124 citation statements)

References 63 publications

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“…absorption band compared to that of liquid water [32,45]. Water molecules located near voidlike trap sites will be able to absorb photons of lower energies and, at the same time, provide a favorable environment for electron solvation [32,46].…”

Section: B Amentioning

confidence: 99%

Wavelength dependence of nanosecond infrared laser-induced breakdown in water: Evidence for multiphoton initiation via an intermediate state

et al. 2015

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Investigation of the wavelength dependence (725 -1025 nm) of the threshold for nanosecond optical breakdown in water revealed steps consistent with breakdown initiation by multiphoton ionization, with an initiation energy of about 6.6 eV. This value is considerably smaller than the autoionization threshold of about 9.5 eV, which can be regarded as band gap relevant for avalanche ionization. Breakdown initiation is likely to occur via excitation of a valence band electron into a solvated state, followed by rapid excitation into the conduction band. Theoretical analysis based on these assumptions suggests that the seed electron density required for initiating avalanche ionization drops from 2.5×10 15 cm -3 at 725 nm to 1.1×10 12 cm -3 at 1025 nm. These results demand changes of future breakdown modeling for water including the use of a larger band gap than previously employed, the introduction of an intermediate energy level for initiation, and consideration of the wavelength dependence of seed electron density.

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Section: B Amentioning

confidence: 99%

Wavelength dependence of nanosecond infrared laser-induced breakdown in water: Evidence for multiphoton initiation via an intermediate state

et al. 2015

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“…A band gap energy E gap = 9.5 eV seems appropriate to consider both vertical and autoionization [16,[70][71][72][73]. What was thought to be the band gap is actually an intermediate energy level between valence and conduction band, which plays a role mainly for breakdown initiation.…”

Section: Band Structure and Ionization Pathways Of Watermentioning

confidence: 99%

Wavelength dependence of femtosecond laser-induced breakdown in water and implications for laser surgery

et al. 2016

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The wavelength dependence of the threshold for femtosecond optical breakdown in water provides information on the interplay of multiphoton, tunneling and avalanche ionization, and is of interest for parameter selection in laser surgery. We measured the bubble threshold from UV to near-IR wavelengths and found a continuous decrease of the irradiance threshold with increasing wavelength λ. Results are compared to the predictions of a numerical model that assumes a bandgap of 9.5 eV and considers the existence of a separate initiation channel via excitation of valence band electrons into a solvated state followed by rapid upconversion into the conduction band. Fits to experimental data yield an electron collision time of ≈ 1 fs, and an estimate for the capacity of the initiation channel. Using that collision time, the breakdown dynamics was explored up to λ = 2 µm. The irradiance threshold first continues to decrease but levels out for wavelengths longer than 1.3 µm. This opens promising perspectives for laser surgery at wavelengths around 1.3 µm and 1.7 µm, which are attractive because of their large penetration depth into scattering tissues.

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“…2) as we had tentatively assigned before. 16,17 In general, TA data at t = 0 fs have coherent signals that arise from the temporally overlapped pump and probe pulses, for example, the transient spectrum may contain a coherent contribution from two photon absorption (2PA) of the solvent 32,33 and solute. We will return to discuss this problem and to definitively identify this 363 nm feature in section IV and, in the interim, provisionally assign this feature to p-MePhS( A ) radical absorption.…”

Section: (B)mentioning

confidence: 99%

Exploring the Energy Disposal Immediately After Bond-Breaking in Solution: The Wavelength-Dependent Excited State Dissociation Pathways of para-Methylthiophenol

et al. 2013

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A wavelength-resolved ( pump = 295, 285, 270 and 267 nm) photodissociation study of paramethylthiophenol (p-MePhSH) in ethanol solution has been performed using femtosecond transient absorption (TA) spectroscopy and the results compared with those from studies of the corresponding photodissociation in cyclohexane solution at 270 nm. Anisotropy spectra are used to identify the electronic character of the initially populated excited state(s). S-H bond fission is found to occur via the dissociative S 2 (1 1 πσ*) state, which can be populated directly, or by ultrafast non-radiative transitions from the S 3 (2 1 ππ*) state, or by very efficient tunneling from the S 1 (1 1 ππ*) state, depending on the excitation wavelength -in line with conclusions from

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Electronic structure of liquid water from polarization-dependent two-photon absorption spectroscopy

Cited by 65 publications

References 63 publications

Wavelength dependence of nanosecond infrared laser-induced breakdown in water: Evidence for multiphoton initiation via an intermediate state

Wavelength dependence of nanosecond infrared laser-induced breakdown in water: Evidence for multiphoton initiation via an intermediate state

Wavelength dependence of femtosecond laser-induced breakdown in water and implications for laser surgery

Exploring the Energy Disposal Immediately After Bond-Breaking in Solution: The Wavelength-Dependent Excited State Dissociation Pathways of para-Methylthiophenol

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