Laser-Induced Fluorescence

Kinsey, James L.

doi:10.1146/annurev.pc.28.100177.002025

Cited by 273 publications

(75 citation statements)

References 4 publications

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“…In this study, the MCS states are numerically solved based on the R-matrix Floquet theory (RFT) [34], and we attempt to find a complete solution, namely, a non-approximated solution, for the single electron DWSL problem within numerical round-off inaccuracy. By evaluating the excess density of state (DOS) [35][36][37][38] of DWSL, it is demonstrated that the DL band (1, 0) is really unstable in a certain region of THz intensity, as shown later. The excess DOS is an important physical quantity because it is associated with the lifetime of the concerned resonance state, and further, it provides the initial characterization for understanding a more complicated problem, for instance, the problem of the transient interband coherent dynamics of a THz-driven semiconductor DWSL.…”

Section: Introductionmentioning

confidence: 76%

Instability of dynamic localization in the intense terahertz-driven semiconductor Wannier-Stark ladder due to the dynamic Fano resonance

et al. 2010

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The lifetime of an electronic Floquet state in a semiconductor Wannier-Stark ladder (WSL) driven by an intense monochromatic THz wave is examined based on the R-matrix Floquet theory, in which an excess density of state (DOS) corresponding to the lifetime is calculated. It is revealed that the dynamic localization (DL) characteristic of this system is unstable against Fano resonance (FR)-like inter-miniband decay mechanism caused by THz-mediated ac-Zener tunneling; in this study, this is termed as dynamic Fano resonance (DFR). The DFR is considered to be a new FR mechanism characterized by both tunable ac-ZT coupling and coexistence with shape resonance.The result obtained here is in sharp contrast with the conventional understanding without the introduction of DFR, in which the DL is very stable such that its lifetime is comparable to or greater than that of the associated WSL. It is found that the DFR mechanism generally becomes more dominant with an increase in the strength of the bias field. Further, we discuss the observation that the spectral pattern of the excess DOS is more involved for a single-photon resonant transition, namely, Ω = ω, than that for a two-photon resonant transition, namely, Ω = 2ω, where Ω and ω represent a Bloch frequency and a THz frequency, respectively. In addition, the criterion for the applicability of the DFR to the present system is also obtained.

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Section: Introductionmentioning

confidence: 76%

Instability of dynamic localization in the intense terahertz-driven semiconductor Wannier-Stark ladder due to the dynamic Fano resonance

et al. 2010

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“…This paper reviews solid-liquid and solid-liquid-liquid refractive-index-matched systems employed in different fields, e.g., multiphase flows, turbomachinery, bio-fluid flows, with an emphasis on liquid-liquid systems. The refractive indices of various aqueous and organic phases found in the literature span the range 1.330-1.620 and 1.251-1.637, respectively, allowing the identification of appropriate combinations to match selected transparent or translucent plastics/polymers, glasses, or custom materials (i) Laser-induced fluorescence (LIF), as described by Kinsey (1977), Liu et al (1977), Walker (1987) and Crimaldi (2008), has been used to provide phenomenological insight as well as quantitative information on the distribution and other key characteristics of the fluid phases, including phase fraction, wave amplitude and frequency, bubble size distribution and frequency, etc. LIF has been utilized in RIM systems by Diez et al (2005), Ovdat and Berkowitz (2006), Liu et al (2006a, b), Ravelet et al (2007), Wu et al (2011), , , amongst others.…”

Section: Introductionmentioning

confidence: 99%

A review of solid–fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid–liquid and multiphase solid–liquid flows

2017

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Experimental techniques based on optical measurement principles have experienced significant growth in recent decades. They are able to provide detailed information with high-spatiotemporal resolution on important scalar (e.g., temperature, concentration, and phase) and vector (e.g., velocity) fields in single-phase or multiphase flows, as well as interfacial characteristics in the latter, which has been instrumental to step-changes in our fundamental understanding of these flows, and the development and validation of advanced models with ever-improving predictive accuracy and reliability. Relevant techniques rely upon well-established optical methods such as direct photography, laser-induced fluorescence, laser Doppler velocimetry/phase Doppler anemometry, particle image/tracking velocimetry, and variants thereof. The accuracy of the resulting data depends on numerous factors including, importantly, the refractive indices of the solids and liquids used. The best results are obtained when the observational materials have closely matched refractive indices, including test-section walls, liquid phases, and any suspended particles. This paper reviews solid–liquid and solid–liquid–liquid refractive-index-matched systems employed in different fields, e.g., multiphase flows, turbomachinery, bio-fluid flows, with an emphasis on liquid–liquid systems. The refractive indices of various aqueous and organic phases found in the literature span the range 1.330–1.620 and 1.251–1.637, respectively, allowing the identification of appropriate combinations to match selected transparent or translucent plastics/polymers, glasses, or custom materials in single-phase liquid or multiphase liquid–liquid flow systems. In addition, the refractive indices of fluids can be further tuned with the use of additives, which also allows for the matching of important flow similarity parameters such as density and viscosity

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“…For the characterization of constituent materials and degradation forms Laser Induced Fluorescence (LIF) and Raman spectroscopy were used [5,6]. For the latter, a portable i-Raman spectrometer (B&W TEK Inc., USA) provided with a 785 nm excitation laser source and a CCD detector thermoelectrically cooled at 10 °C was chosen.…”

Section: Techniquesmentioning

confidence: 99%

Laser-based techniques for a multidisciplinary action aimed at the restitutive restoration of S. Costanzo church in Ronciglione (Italy)

Spizzichino¹,

Caneve²,

Ciaffi³

et al. 2017

Proceedings of the International Conference LACONA XI

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In the framework of the COBRA (Conservation of Cultural Heritage through Radiation and Enabling Technologies) project a multidisciplinary study was carried out in order to restore the mural painting of the dome of the S. Costanzo church in Ronciglione (Italy). Large difficulties were met during the restitutive restoration of the original renaissance fresco decorating the dome, patronized by the Italian Ministry of Cultural Heritage (SABAP RM MET). In fact, two and sometimes three layers of paint, which lays on an extremely crumbled substrate were detected on the surface, in addition to large, deep and complex degradation forms with the presence of efflorescence. To solve such a critical situation, researchers, conservators and laser cleaning system suppliers collaborated to plan the most appropriate intervention. Laser-based diagnostics were employed to characterize different areas of the fresco surface before and after cleaning tests. In particular, ENEA offered its prototypes of LIF (Laser Induced Fluorescence) and RGB-ITR (Red Green Blue Imaging Topological Radar, an innovative 3D colour laser scanner) in addition to a laser Raman system and an infrared camera for thermographic measurements for both the material and degradation recognition and a micro-structural study. The results obtained allowed pointing at the most suitable restoration and conservation strategies. The cleaning tests were performed with both classical methods and lasers made available by El.En. group. Different operative parameters such as pulse duration, repetition rate, energy were tested. The laser employed made it possible to overpass the difficulties encountered by other cleaning techniques: degradation and painting layers were removed selectively, allowing bringing to light the original surface.

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Laser-Induced Fluorescence

Cited by 273 publications

References 4 publications

Instability of dynamic localization in the intense terahertz-driven semiconductor Wannier-Stark ladder due to the dynamic Fano resonance

Instability of dynamic localization in the intense terahertz-driven semiconductor Wannier-Stark ladder due to the dynamic Fano resonance

A review of solid–fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid–liquid and multiphase solid–liquid flows

Laser-based techniques for a multidisciplinary action aimed at the restitutive restoration of S. Costanzo church in Ronciglione (Italy)

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