Results 281 to 290 of about 29,191 (325)

Pulsed Photoacoustic Effect in Semiconductors

Japanese Journal of Applied Physics, 1991
Acoustic and thermal components of signal waveforms generated in Si and CdS samples, which are irradiated by Nd:YAG and Ruby laser pulse, are detected by PZT and PVF2 transducers over a time range of 0.1 µs to several ms. The sound velocity of propagating longitudinal wave and the vibration modes of the sample can be analyzed from the acoustic wave ...
Masahito Watanabe, Yoichi Okamoto, Jun Morimoto, Toru Miyakawa, Hidenari Ueda   +4 more
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Effect of temperature and wavelength on photoacoustic signals

International Photonics and OptoElectronics, 2015
In this paper, the effect of temperature and wavelength on photoacoustic signals was qualitatively studied.
Yanfang Cao, Yaoyao Cui, Zhile Han, Xiaohua Jian, Yang Jiao, Yongjia Xiang   +5 more
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Photoacoustic effect in piezoelectric ceramics

Journal of the Optical Society of America, 1980
Audiofrequency signals produced by the absorption of chopped light in silvered piezoelectric ceramic discs have been measured as a function of chopping frequency, optical wavelength, optical power, transducer size, and size of illuminated area. The results show that the detected signal varies inversely as ω, is not strongly wavelength dependent in the ...
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Photoacoustic and currentacoustic effects in optoelectronic devices

Solid-State Electronics, 1985
Abstract A general theoretical framework for the interpretation of the acoustic detection of heat power produced in semiconductive photodetectors and light-emitting diodes is developed on the basis of the photoacoustic effect theory outlined by Rosencwaig [1].
B. Rheinländer, W. Thielemann
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Effect of metallization on porphyrin photoacoustic response

Chemical Physics Letters, 2020
Abstract Photoacoustic imaging (PAI) has been evaluated to visualize small neoplastic lesions inside normal tissues. PAI is based on the detection of pressure waves generated due to the absorption of light energy by a photosensitizer (PS) within the tissue.
Joao H. Uliana, Iouri Borissevitch, Iouri Borissevitch, André M. Amado, Theo Z. Pavan   +4 more
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Helmholtz resonance effect in photoacoustic cells

Applied Optics, 1979
Some types of photoacoustic spectroscopy sample cells exhibit acoustic resonances which are not explained by organ pipe or Bessel mode analysis. It is demonstrated here that one type of acoustic resonance encountered is explained by a Helmholtz resonator analysis.
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Amplitude and phase study of the photoacoustic effect

Journal of Physics D: Applied Physics, 1992
Measurements are reported on the amplitude and phase of the photoacoustic signal for a range of light chopping frequencies between approximately 0.2-800 Hz. At low chopping frequencies existing theories deviate markedly from observation. A simple phenomenological model has been devised to remedy this, with encouraging results.
G L R Mair, G P Papadopoulos
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Optical Measurements of Acoustic and Photoacoustic Effects [PDF]

IEEE 1986 Ultrasonics Symposium, 1986
Optical sensors for acoustic waves and photoThey are easy to scan and they can have acoustic effects are used because no mechanical contact needs to be made to the solid material being examined. very good definition. The major disadvantage is that they are extremely insensitive compared to piezoelectric detectors. In photacoustic applications, they are
Gordon S. Kino, B.T. Khuri-Yakub, J. T. Fanton   +2 more
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The Photoacoustic Effect at Phase Transitions [PDF]

, 1984
The pressure response of the gas to the absorbed light is determined essentially by the thermal properties of the sample. At a first order phase transition, the latent heat influences strongly the pressure signal. Recently, first experimental observations of the PA at phase transitions in various substances have been published.
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Study of Edge Effect in Photoacoustic Microscopy

Japanese Journal of Applied Physics, 1986
The edge effect in microphone photoacoustic microscopy has been studied experimentally. It has been observed that the amplitude of the photoacoustic signal is enhanced nearly exponentially when the exciting laser spot approaches the sample edge. The phase also shows a characteristic shift near the edge.
Tsutomu Yamaguchi, Shigeki Sugimoto, Masanori Hangyo, Shin-ichi Nakashima, Akiyoshi Mitsuishi   +4 more
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