Electrical conductivity in the laser beam channel

Thermal diffusivities of metallic glass ribbons have been measured at different annealing stages by the photoacoustic method using a gas-coupled microphone. In a symmetrical excitation geometry of the photoacoustic experiment, heat waves were generated by a laser beam at both sides of the foils. Values of thermal diffusivities have been compared with those of the electrical conductivity measured on the same samples.

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Electrical parameters of a laser beam channel in atmosphere. I

Izvestiya vysshikh uchebnykh zavedenii. Fizika ◽

10.17223/00213411/62/4/16 ◽

2019 ◽

pp. 16-20

Author(s):

S. F. Balandin ◽

◽

et al.

Keyword(s):

Laser Beam ◽

Electrical Parameters ◽

Beam Channel

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Electrical Parameters of a Laser Beam Channel in the Atmosphere. I

Russian Physics Journal ◽

10.1007/s11182-019-01749-1 ◽

2019 ◽

Vol 62 (4) ◽

pp. 576-580 ◽

Cited By ~ 3

Author(s):

S. F. Balandin ◽

V. A. Donchenko ◽

Al. A. Zemlyanov ◽

V. F. Myshkin ◽

V. A. Khan ◽

...

Keyword(s):

Laser Beam ◽

Electrical Parameters ◽

Beam Channel

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Electrical parameters of a laser beam channel in atmosphere. II

Izvestiya vysshikh uchebnykh zavedenii. Fizika ◽

10.17223/00213411/62/5/3 ◽

2019 ◽

pp. 3-8

Author(s):

E.S. Abramova ◽

◽

V.A. Khan ◽

V.F. Myshkin ◽

Al.A. Zemlyanov ◽

...

Keyword(s):

Laser Beam ◽

Electrical Parameters ◽

Beam Channel

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Characterization of thermal modulation of electrical conductivity: a small volume absorbance measurement technique

Canadian Journal of Chemistry ◽

10.1139/v89-178 ◽

1989 ◽

Vol 67 (7) ◽

pp. 1178-1186 ◽

Cited By ~ 2

Author(s):

Robert McLaren ◽

Norman J. Dovichi

Keyword(s):

Electrical Conductivity ◽

Laser Beam ◽

Laser Power ◽

Spot Size ◽

Electrode Spacing ◽

Deuterated Water ◽

Gaussian Laser Beam ◽

Thermal Modulation ◽

Absorbance Detection ◽

The Difference

Laser-induced thermal modulation of electrical conductivity is a new photothermal method for the measurement of minute absorbance in sub-nanoliter liquid samples. In this paper, a model is presented for the technique. This model is based upon the interaction of a Gaussian laser beam with a cylindrical, homogeneous electrolytic resistor. Particularly simple results are produced if the laser beam spot size is much smaller than the diameter of the electrodes. The theory is verified with respect to the electrode spacing and to the laser power, spot size, and chopping frequency; the highest sensitivity occurs with low chopping frequency, high laser power, and small electrode spacing. The signal is independent of laser spot size, as long as the beam does not illuminate the electrode surface. The precision of the measurement is dominated by shot noise in the current flow through the electrolytic resistor. One point absorbance detection limits of 5.5 × 10−6 measured across the 76-μm diameter electrode wires are obtained in aqueous solution with a 5- mW helium–neon laser. With this instrument, the difference in the absorbance of water and deuterated water is easily determined at 632.8 nm. Keywords: thermal modulation of electrical conductivity.

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Фотоэлектрические преобразователи лазерного излучения на основе гетероструктур InP(GaAs)/InP, полученные методом жидкофазной эпитаксии

Письма в журнал технической физики ◽

10.21883/pjtf.2018.18.46609.17397 ◽

2018 ◽

Vol 44 (18) ◽

pp. 31

Author(s):

Н.С. Потапович ◽

Н.Х. Тимошина ◽

В.П. Хвостиков

Keyword(s):

Laser Beam ◽

Laser Power ◽

Power Converters ◽

Power Transmission ◽

Wireless Power ◽

Wireless Power Transmission ◽

Beam Channel

AbstractWe have studied the possibility of creating laser-power converters based on LPE-grown InP(GaAs)/InP heterostructures intended for wireless power transmission via a laser beam channel at wavelengths λ ≈ 1.06–1.2 μm.

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Removing Substrate Background in TEM Microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052857 ◽

1974 ◽

Vol 32 ◽

pp. 568-569

Author(s):

John C. Russ ◽

Nicholas C. Barbi

Keyword(s):

Electrical Conductivity ◽

Rapid Growth ◽

Organic Film ◽

Absolute Concentration ◽

Background Signal ◽

X Ray ◽

Elemental Concentrations ◽

Transmission Electron ◽

Electron Microscopes ◽

The Continuum

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

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Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076639 ◽

1983 ◽

Vol 41 ◽

pp. 606-607

Author(s):

Klaus-Ruediger Peters ◽

Samuel A. Green

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Critical Point ◽

Metal Films ◽

High Magnification ◽

Osmium Impregnation ◽

Instrumental Resolution ◽

20 Nm ◽

Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

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