Interferometric determination of the surface profile of a liquid heated by a laser beam

Calatroni, J.; Costa, German Da

doi:10.1016/0030-4018(82)90079-7

Cited by 23 publications

(11 citation statements)

References 5 publications

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“…Such a pattern, which has not been observed in the small-scale experiments, always appears perpendicular to the scanning direction and parallel to the strip laser beam. 22 To check this scenario we carried out several irradiations with different widths of the laser beam strip. Rippling effects with periodicity of the order of the laser wavelength have been widely reported during laser irradiation of metals, semiconductors and dielectric surfaces.…”

Section: Resultsmentioning

confidence: 99%

Laser application for optical glass polishing

et al. 1998

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Rapid generation of large area polished optical surfaces by high-power CO 2 laser irradiation is shown. Results focus on glasses with high expansion coefficients (␣у10 Ϫ5 /°C) conventionally used in the optical industry. The technique involves active beam integration to obtain an intensity irradiation profile with a good uniformity over large spot sizes and is applied to preheated glass samples with initial rms roughness up to 500 nm. To find out the conditions for successful and reliable use of the proposed laser polishing method, the laser-driven heating process was monitored by means of the surface and depth temperature distributions. Whereas the former was determined in situ from the IR radiation emitted by the glass surface, the latter was obtained by comparison of the IR radiation emitted by the bulk sample with a theoretical model. Laser polishing of 5000 mm 2 glass surfaces is reported and processes involved in the modification of the surface texture of the irradiated samples are described and discussed. © 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)04101-4] Subject terms: high power CO 2 laser application; rapid generation of polished glass surface; in-process temperature measurements; laser beam integration.

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Section: Resultsmentioning

confidence: 99%

Laser application for optical glass polishing

et al. 1998

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“…The quasi-stationary diameter

of this ring is called the PTC signal, as shown in Figure 1 c. In fact, the PTC effect can be considered as a particular stage of a more general concentration-capillary effect, which was discovered by Bezuglyi in 1975 while irradiating the iodine solution with a mercury lamp [ 28 ]. In its classical form, the TC phenomenon was studied in the late 1970s while irradiating heavy oil fractions with a Helium-Neon (He-Ne) laser [ 29 , 30 ]. The PTC signal is called both the diffraction [ 28 ] and interference [ 30 ] patterns.…”

Section: Methodsmentioning

confidence: 99%

Photothermocapillary Method for the Nondestructive Testing of Solid Materials and Thin Coatings

Zykov

Вавилов

Kuimova

2021

Sensors

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The photothermocapillary (PTC) effect is a deformation of the free surface of a thin liquid layer on a solid material that is caused by the dependence of the coefficient of surface tension on temperature. The PTC effect is highly sensitive to variations in the thermal conductivity of solids, and this is the basis for PTC techniques in the non-destructive testing of solid non-porous materials. These techniques analyze thermal conductivity and detect subsurface defects, evaluate the thickness of thin varnish-and-paint coatings (VPC), and detect air-filled voids between coatings and metal substrates. In this study, the PTC effect was excited by a “pumped” Helium-Neon laser, which provided the monochromatic light source that is required to produce optical interference patterns. The light of a small-diameter laser beam was reflected from a liquid surface, which was contoured by liquid capillary action and variations in the surface tension. A typical contour produces an interference pattern of concentric rings with a bright and wide outer ring. The minimal or maximal diameter of this pattern was designated as the PTC response. The PTC technique was evaluated to monitor the thickness of VPCs on thermally conductive solid materials. The same PTC technique has been used to measure the thickness of air-filled delaminations between a metal substrate and a coating.

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“…A review of optical methods applied to this kind of experiments is made in reference [6]. The interferometric techniques used to obtain the photographs of figures 3-4 are described in reference [7].…”

Section: Fig1mentioning

confidence: 99%

“…All the curves in each photograph of figure 3 correspond to the same meridian section of the surface. The surface profiles measured from these photographs are presented in the graphs at the bottom of the picture : they are in good agreement with the theoretical results of figure 2. Another interferometric technique [7] allows one to record the equal-height curves of the surface. The results are shown in figure 4.…”

Section: Fig1mentioning

confidence: 99%

Competition between capillary and gravity forces in a viscous liquid film heated by a Gaussian laser beam

Costa

1982

J. Phys. France

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The free-surface of a liquid sample (heavy oil) is locally heated by irradiation with a Gaussian laser beam. Photographic records of the surface profile and flow pattern are presented. The free-surface passes by an earlier dilatation stage, followed by the formation of a pit in the top of the expanded region. A theoretical analysis based on the stationary solution of Navier-Stokes equation with temperature-dependent density and surface-tension is made. It is shown that the sign of the surface-height variations in the hot region depends critically on the values of the dimensionless quantities characterizing the experiment. The surface profile and the velocity distribution are calculated and compared with the experimental results. We conclude that the phenomena observed are due to competition between the density- and surface-tension gradients

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Interferometric determination of the surface profile of a liquid heated by a laser beam

Cited by 23 publications

References 5 publications

Laser application for optical glass polishing

Laser application for optical glass polishing

Photothermocapillary Method for the Nondestructive Testing of Solid Materials and Thin Coatings

Competition between capillary and gravity forces in a viscous liquid film heated by a Gaussian laser beam

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