scholarly journals Picosecond two-photon absorption laser-induced fluorescence (ps-TALIF) in krypton: The role of photoionization on the density depletion of the fluorescing state Kr 5p′[3/2]2

2021 ◽  
Vol 28 (4) ◽  
pp. 043301
Author(s):  
K. Gazeli ◽  
X. Aubert ◽  
S. Prasanna ◽  
C. Y. Duluard ◽  
G. Lombardi ◽  
...  
Keyword(s):  
Laser Induced Fluorescence ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Density Depletion

scholarly journals Progresses on the Use of Two-Photon Absorption Laser Induced Fluorescence (TALIF) Diagnostics for Measuring Absolute Atomic Densities in Plasmas and Flames

Plasma ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 145-171
Author(s):  
Kristaq Gazeli ◽  
Guillaume Lombardi ◽  
Xavier Aubert ◽  
Corinne Y. Duluard ◽  
Swaminathan Prasanna ◽  
...  
Keyword(s):  
Optical Transition ◽  
Thin Film Deposition ◽  
Laser Induced Fluorescence ◽  
Film Deposition ◽  
Stimulated Emission ◽  
Photon Absorption ◽  
Collisional Quenching ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Wide Range

Recent developments in plasma science and technology have opened new areas of research both for fundamental purposes (e.g., description of key physical phenomena involved in laboratory plasmas) and novel applications (material synthesis, microelectronics, thin film deposition, biomedicine, environment, flow control, to name a few). With the increasing availability of advanced optical diagnostics (fast framing imaging, gas flow visualization, emission/absorption spectroscopy, etc.), a better understanding of the physicochemical processes taking place in different electrical discharges has been achieved. In this direction, the implementation of fast (ns) and ultrafast (ps and fs) lasers has been essential for the precise determination of the electron density and temperature, the axial and radial gradients of electric fields, the gas temperature, and the absolute density of ground-state reactive atoms and molecules in non-equilibrium plasmas. For those species, the use of laser-based spectroscopy has led to their in situ quantification with high temporal and spatial resolution, with excellent sensitivity. The present review is dedicated to the advances of two-photon absorption laser induced fluorescence (TALIF) techniques for the measurement of reactive species densities (particularly atoms such as N, H and O) in a wide range of pressures in plasmas and flames. The requirements for the appropriate implementation of TALIF techniques as well as their fundamental principles are presented based on representative published works. The limitations on the density determination imposed by different factors are also discussed. These may refer to the increasing pressure of the probed medium (leading to a significant collisional quenching of excited states), and other issues originating in the high instantaneous power density of the lasers used (such as photodissociation, amplified stimulated emission, and photoionization, resulting to the saturation of the optical transition of interest).

OPTICAL LIMITING STUDIES IN PHOTOREFRACTIVE PURE AND IRON-DOPED Bi12SiO20 CRYSTALS

2000 ◽  
Vol 09 (02) ◽  
pp. 217-225 ◽  
Author(s):  
P. SREERAMANA AITHAL ◽  
P. PREM KIRAN ◽  
D. NARAYANA RAO
Keyword(s):  
Excited State Absorption ◽  
Optical Limiting ◽  
Photon Absorption ◽  
Limiting Behavior ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Iron Incorporation ◽  
Optical Limiter ◽  
Level Model

Optical limiting characteristics of pure and 150 ppm Fe-doped Bi 12 SiO 20 (BSO:Fe) crystals are studied at high intensity nanosecond pulse regime. When the input light is at 532 nm and at 595 nm with 6 ns pulse duration, a good optical limiting behavior is observed due to simultaneous effect of trap assisted excited state absorption and two photon absorption. The precise role of the internal defects due to impurity centers present in the crystal lattice is explained on the basis of a four level model. This study reveal that the increased nonlinear absorption due to iron incorporation in BSO makes it an excellent passive optical limiter.

Two-photon absorption, laser-induced fluorescence detection of Cl atoms

1982 ◽  
Vol 86 (5-6) ◽  
pp. 458-462 ◽  
Author(s):  
Michael Heaven ◽  
Terry A. Miller ◽  
Richard R. Freeman ◽  
J.C. White ◽  
Jeffrey Bokor
Keyword(s):  
Fluorescence Detection ◽  
Laser Induced Fluorescence ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Laser Induced Fluorescence Detection ◽  
Two Photon ◽  
Cl Atoms
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