Absorption and emission characteristics of femtosecond laser plasma filaments in the air

Ilyin, A. A.; Golik, S. S.; Shmirko, K. A.

doi:10.1016/j.sab.2015.08.002

Cited by 31 publications

(7 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The previous study by Zeng et al demonstrated distinct revival of nitrogen as long as 50 ps . Because the decoherence of revival depends on the collision of nitrogen, which is significantly hindered by the positive charge of N 2 + , the revival time should match the fluorescence lifetime of 391 nm fluorescence, i.e., 400 ps reported by Ilyin et al With the time-averaged distribution modeled in Figure e, the anisotropy of the fluorescence is highly dependent on the laser field intensity. The moderately aligned angle makes the spatial distribution difficult to observe when the electric field is 0.5 × 10 14 W/cm 2 .…”

mentioning

confidence: 73%

Effect of Molecular Orbital Angular Momentum on the Spatial Distribution of Fluorescence during Femtosecond Laser Filamentation in Air

Sun

Chu

et al. 2020

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

Nonuniform azimuthal distribution of N 2 + fluorescence emitted from the femtosecond laser filament in air was discovered. The fluorescence is stronger when the detector is placed perpendicular or parallel to the laser polarization. The experimental results have been confirmed by the theoretical calculation that the azimuthal distribution of fluorescence is reproduced by the convolution of the transition of the dipole and the molecular alignment in the strong laser field. The results would provide new insight into laser−molecule interactions during filamentation, which are important in practice for remote sensing using filamentation.

show abstract

mentioning

confidence: 73%

Effect of Molecular Orbital Angular Momentum on the Spatial Distribution of Fluorescence during Femtosecond Laser Filamentation in Air

Sun

Chu

et al. 2020

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

show abstract

“…The vibrational radiative lifetime of the d 3 Π g C 2 electronic state is 75–200 ns (ν′ = 0–5), which is involved in the Swan band emission (d 3 Π g –a 3 Π u ). Tightly focused femtosecond laser-induced filament formation was observed in air at E crit = 0.25 mJ and P crit = 5.2 GW (Ti–Sapphire laser, 48 fs) . The emission of molecular bands was short-lived (N 2 337 nm and N 2 + 391.2 nm up to 1 ns); however, the atomic lines were significantly longer (atomic triplets of N I 746 and O I 777 nm up to 150 ns).…”

Section: Resultsmentioning

confidence: 99%

Formation of CN Radical from Nitrogen and Carbon Condensation and from Photodissociation in Femtosecond Laser-Induced Plasmas: Time-Resolved FT-UV–Vis Spectroscopic Study of the Violet Emission of CN Radical

et al. 2020

View full text Add to dashboard Cite

Exploring the formation of diatomic radicals in femtosecond plasmas is important to establish the most dominant kinetic pathways following ionization and dissociation of small molecules. In this work, cyano radical formation has been studied from bromoform, acetonitrile, and methanol in nitrogen and argon plasmas created with a focused femtosecond laser beam operating at 100 kHz repetition rate and 1030 nm wavelength with 43 fs pulse length and 250 μJ pulse energy. Time-resolved Fourier transform fluorescence spectroscopy was applied in the ultraviolet−visible (UV−vis) spectral range for the characterization of the rotational and vibrational temperatures of the CN(B) radicals via fitting the experimental data. The high repetition rate of the laser allows efficient coupling with the step-scan Fourier transform spectroscopy method. Coulomb explosion at the very high intensity (∼10 16 W/cm 2 ) resulted in the formation of nascent atoms, ions, and electrons. The condensation reactions of carbon and reactive nitrogen species resulted in the formation of CN(B 2 Σ + ) radicals and C 2 (d 3 Π g ) dicarbon molecules/radicals. The CN(B) radicals were formed at the highest concentration in the case of bromoform because the weak carbon−bromine bonds resulted in reactive carbon atoms and CH radicals, which are reactive precursors for the CN(B) radical formation. In the case of acetonitrile, immediate production of CN(B) is observed with nanosecond resolution, which suggests that the CN is formed either via photodetachment or via roaming reaction associated with the Coulomb explosion of the parent molecule. The nascent rotational temperature was very high (∼6000−8500 K) and rapidly decreased in all instances within 40 ns with bromoform and acetonitrile. The highest vibrational temperature (∼7800 K) was observed in an acetonitrile/Ar mixture that decreased in about 30 ns and then increased in the observed time window. The vibrational temperature increased in all samples between 30 and 200 ns. The time dependence of fluorescence is described with a monoexponential decay in the case of acetonitrile/Ar and with biexponential decays in all other instances in the 0−250 mbar total pressure range. The shorter time constant is close to the radiative lifetime of CN(B) emission (∼60−80 ns), which can be attributed to the CN(B) radicals produced in the first few collisions at lower pressures. The longer CN(B) emission is from CN(B) created by slower chemical reactions involving carbon atoms, C 2 radicals, and reactive nitrogen-containing species.

show abstract

“…Спектральные методы определения химического состава жидких и газовых сред являются мощным инструментом аналитической химии. Базируясь на двух основных принципах формирования оптического сен-сорного отклика -изменении оптического поглощения и/или парамет-ров люминесценции сенсорной системы в присутствии определяемого вещества (аналита), данные методы обеспечивают селективность и вы-сокую чувствительность [1][2][3][4][5]. Одним из способов построения хемосен-сорных систем такого вида является внедрение в оптически инертную матрицу оптически активного элемента, формирующего хемосенсорный отклик в присутствии аналита [6][7][8].…”

Section: поступило в редакцию 15 марта 2017 гunclassified

Сенсорная Система Для Регистрации Малых Концентраций Сероводорода В Водных Растворах На Основе Люминесцентного Белкового Комплекса В Биополимерной Матрице

Сергеев¹,

Леонов²,

Каменев³

et al. 2017

Письма В Журнал Технической Физики

View full text Add to dashboard Cite

Поступило в Редакцию 15 марта 2017 г.Представлены результаты исследований люминесцентных белковых комплек-сов на основе белка миоглобина с ковалентно связанным люминофором CY3, сформированных в пленке полисахарида агарозы, как элементов, чувствитель-ных к растворенному в воде сероводороду. В присутствии аналита происходит изменение спектра поглощения миоглобина, которое оказывает влияние на эффективность возбуждения люминофора и практически не влияет на его спектр эмиссии. Данный эффект демонстрирует возможность создания люми-несцентной сенсорной системы, оптический отклик которой формируется за счет изменения эффективности возбуждения люминесценции чувствительного элемента, вызванного присутствием аналита. Предел обнаружения растворен-ного в воде сероводорода составил 100 pM.

show abstract

Absorption and emission characteristics of femtosecond laser plasma filaments in the air

Cited by 31 publications

References 44 publications

Effect of Molecular Orbital Angular Momentum on the Spatial Distribution of Fluorescence during Femtosecond Laser Filamentation in Air

Effect of Molecular Orbital Angular Momentum on the Spatial Distribution of Fluorescence during Femtosecond Laser Filamentation in Air

Formation of CN Radical from Nitrogen and Carbon Condensation and from Photodissociation in Femtosecond Laser-Induced Plasmas: Time-Resolved FT-UV–Vis Spectroscopic Study of the Violet Emission of CN Radical

Сенсорная Система Для Регистрации Малых Концентраций Сероводорода В Водных Растворах На Основе Люминесцентного Белкового Комплекса В Биополимерной Матрице

Contact Info

Product

Resources

About