Photothermal Methods

2016 ◽  
Author(s):  
W. Plieth ◽  
G. S. Wilson ◽  
C. Gutierrez De La Fe
Keyword(s):  
Photothermal Methods

scholarly journals Real time analysis of erythrocyte sedimentation by photothermal methods

1994 ◽  
Vol 04 (C7) ◽  
pp. C7-469-C7-472 ◽  
Author(s):  
J. S. Antoniow ◽  
M. Egée ◽  
M. Chirtoc ◽  
C. Bissieux ◽  
G. Potron
Keyword(s):  
Real Time ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Erythrocyte Sedimentation ◽  
Photothermal Methods

Thermo-optical properties of iron-doped low silica calcium aluminosilicate glasses determined by photothermal methods

2005 ◽  
Vol 125 ◽  
pp. 197-199
Author(s):  
R. K. Miura ◽  
P. T. Udo ◽  
J. H. Rohling ◽  
E. A. Falcão ◽  
A. N. Medina ◽  
...  
Keyword(s):  
Optical Properties ◽  
Aluminosilicate Glasses ◽  
Iron Doped ◽  
Calcium Aluminosilicate ◽  
Photothermal Methods

Absorption losses and thermal diffusivity of optical fibers investigated by photothermal methods: theory and experiments

1983 ◽  
Vol 61 (9) ◽  
pp. 1334-1346 ◽  
Author(s):  
Dominique Chardon ◽  
Serge J. Huard
Keyword(s):  
Thermal Diffusivity ◽  
Absorption Coefficient ◽  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Modulation Frequency ◽  
Threshold Value ◽  
Phase Delay ◽  
Algebraic Expression ◽  
Photothermal Methods ◽  
Scattering Losses

Both the absorption coefficient and the thermal diffusivity of an optical fiber have been measured using photothermal methods: photoacoustics (P.A.) and photothermal deflection (P.D.). The amplitude of the photothermal signal is proportional to the heat density generated in the fiber core. This in turn is proportional to the light absorption coefficient β. Thus, these techniques allow one to separate the absorption and Rayleigh scattering losses. The results obtained by the two methods are in agreement. A threshold value of 10 dB km−1 mW has been determined experimentally. In both cases, the device is calibrated by replacing the fiber with a heated electric wire. Moreover, the heat must diffuse from the core to the gas so that when the light is modulated, a phase delay appears. A study of phase delay versus modulation frequency gives the thermal diffusivity of the fiber. This is required in order to improve fiber sensors.Theoretically, the cylindrical geometry of the sample permits simple calculations. The thermoelastic equations in solids and coupled thermodynamic ones in the gas have been solved without neglecting viscosity effects. Noting that silica is almost unexpansible, an algebraic expression of the signal has been obtained without any assumptions on the gas transformation processes. Finally, the P.A. and P.D. techniques are compared and some extensions are presented.

Characterization of vapor and aerosol flows by photothermal methods

1986 ◽  
Vol 64 (9) ◽  
pp. 1121-1123 ◽  
Author(s):  
H. Sontag ◽  
A. C. Tam
Keyword(s):  
Laser Heating ◽  
Thermal Emission ◽  
Pulsed Laser ◽  
Mie Scattering ◽  
Beam Deflection ◽  
Photothermal Heating ◽  
Excitation Laser ◽  
Photothermal Methods ◽  
Pulsed Laser Heating

Pulsed laser heating is used to label aerosols or absorbing vapors in a flow. In an absorbing vapor, the photothermal heating creates a travelling thermal lens that can be detected by a probe-beam deflection scheme yielding information on flow velocity and the concentration of absorbing species. The absorption by volatile aerosols is detected by transient variation in Mie scattering caused by particle evaporation. In addition, the velocity of a single moving aerosol can be measured by monitoring its infrared thermal emission induced by an excitation laser beam.

On the use of photothermal methods for thermal characterization of sedimentary rocks from the Paraná Basin in Brazil

2013 ◽  
Vol 43 ◽  
pp. 121-126 ◽  
Author(s):  
A.O. Guimarães ◽  
D.A. Viana ◽  
T.C. Cordeiro ◽  
J.A. Sampaio ◽  
E.C. da Silva ◽  
...  
Keyword(s):  
Sedimentary Rocks ◽  
Thermal Characterization ◽  
Paraná Basin ◽  
Photothermal Methods ◽  
Parana Basin
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