Results 271 to 280 of about 29,191 (325)

Photoacoustic effect in a flowing liquid

Applied Optics, 1985
In certain applications of photoacoustic spectroscopy it is desirable to measure the photoacoustic signal from a liquid which is in motion. This may be the case, for example, in the study of corrosion at a solid-liquid interface. To understand how the photoacoustic signal is altered by the motion of the sample, experiments were performed on a specially
Richard S. Quimby, Andrew I. Sheinis
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Moiré signals by the photoacoustic effect

Optics Letters, 1990
We report the detection of moiré displacement signals using the photoacoustic effect. By using the transmission and reflection (absorption) gratings with a 25microm pitch, the lateral displacement of the grating is detected from the photoacoustic signals.
Shuzo Hattori, Kazuhiro Hane, S. Watanabe, Tetsumi Goto   +3 more
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The Photoacoustic Effect in Semiconductors

physica status solidi (b), 1983
AbstractA theory of the photoacoustic effect (PAE) in semiconductors is developed for the region of fundamental absorption, taking into account the generation of free electrons and holes, their diffusion, and recombination. The temperature on the illuminated surface of a semiconductor is calculated in a general form.
Vladimir A. Sablikov, V. B. Sandomirskii
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Theory of the photoacoustic effect with solids

Journal of Applied Physics, 1975
When chopped light impinges on a solid in an enclosed cell, an acoustic signal is produced within the cell. This effect is the basis of a new spectroscopic technique for the study of solid and semisolid matter. A quantitative derivation is presented for the acoustic signal in a photoacoustic cell in terms of the optical, thermal, and geometric ...
Allan Rosencwaig, Allen Gersho
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Photoacoustic Spectroscopy — Photoacoustic and Photothermal Effects

1990
Definition. Photoacoustic (PA) or optoacoustic measurements in the original, strict sense comprise the detection of acoustic waves which arise from non-radiative de-excitation (radiationless transition) of the sample as a consequence of absorption of continuously amplitude-modulated light.
C. Buschmann, H. Prehn
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Emissivity determination using the photoacoustic effect

Applied Optics, 2018
We show that emissivities in the near infrared can be determined relative to a reference surface employing the photoacoustic effect. The photoacoustic cell is equipped with two windows and a pair of synchronously moving chopping wheels so that the cell alternately views the test and the reference surface.
Gerald J. Diebold, Yaqi Zhang
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The photoacoustic effect generated by an incompressible sphere

The Journal of the Acoustical Society of America, 2002
An incompressible sphere with a vanishing thermal expansivity suspended in a fluid can generate a photoacoustic effect when the heat deposited in the sphere by a light beam diffuses into the surrounding liquid causing it to expand and launch a sound wave.
Gerald J. Diebold, Andrew C. Beveridge, Theron J. Hamilton   +2 more
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Photoacoustic observation of the exciton effect in GaSe

Applied Optics, 1985
Photoacoustic and absorption spectra of single crystals of GaSe at room temperature have been studied in the neighborhood of the intrinsic absorption edge. Analysis of the spectra showed formation of excitons. This is the first time that the exciton effect has been observed with photoacoustic spectroscopy.
Todorovic Dm, Nikolic Pm
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Theory of the photoacoustic effect in condensed matter

Applied Optics, 1982
The basic equations governing the photoacoustic effect in condensed matter are derived based on themoelastic considerations. A general solution is given for the case when the pulsed light beam is used as the activation source. Some special cases where thermal diffusion is negligible are discussed.
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Photoacoustic effect and the physics of waves

American Journal of Physics, 1980
The photoacoustic effect is the basis for photoacoustic spectroscopy, a rapidly developing technique for studying optical absorption in many solid and liquid samples which are difficult to study by conventional means. Understanding of the effect requires knowledge of both acoustic and thermal waves, making this an interesting problem in the application
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