A Laser–Speckle Correlation Technique for Thickness Determination of Optically Thin Transparent Layers

2011 ◽  
Author(s):  
Johannes Lettner ◽  
Bernhard G. Zagar
Keyword(s):  
Laser Speckle ◽  
Correlation Technique ◽  
Thickness Determination ◽  
Speckle Correlation

Laser speckle correlation technique application for study of aluminum nanopowder combustion

2020 ◽  
Vol 59 (5) ◽  
pp. 1263
Author(s):  
L. Li ◽  
A. V. Mostovshchikov ◽  
A. P. Ilyin ◽  
I. D. Sytnik ◽  
F. A. Gubarev
Keyword(s):  
Laser Speckle ◽  
Correlation Technique ◽  
Speckle Correlation ◽  
Aluminum Nanopowder

scholarly journals Numerical model for evaluating the speckle activity and characteristics of bone tissue under the biospeckle laser system

2021 ◽  
pp. 2150020
Author(s):  
Xin Tang ◽  
Ping Zhong ◽  
Yinrui Gao ◽  
Haowei Hu
Keyword(s):  
Bone Tissue ◽  
Temporal Evolution ◽  
Ex Vivo ◽  
Laser System ◽  
Laser Speckle ◽  
Correlation Technique ◽  
Volume Scattering ◽  
Current Time ◽  
Speckle Correlation ◽  
Spatio Temporal

This paper discusses and studies the composition and characteristics of biospeckle on the surface of bone tissues. We used a laser speckle device to capture biospeckle patterns from fresh pig bone tissue. Traditional speckle activity metrics were used to measure the speckle activity of ex vivo bone tissue over time. Both Gaussian and Lorentzian correlation functions were used to characterize the ordered and disordered motion of the bone surface, together with volume scattering, to construct the model. Using the established mathematical model of the spatio-temporal evolution of the biospeckle pattern, it is possible to account for the presence of volume scattering from the biospeckle of bones, quantify the ordered or disordered motions in the biological speckle activity at the current time, and assess the ability of laser speckle correlation technique to determine biological activity.

Determination of the plastic zone by laser-speckle correlation

1991 ◽  
Vol 31 (4) ◽  
pp. 348-352 ◽  
Author(s):  
Y. Z. Dai ◽  
C. J. Tay ◽  
F. P. Chiang
Keyword(s):  
Plastic Zone ◽  
Laser Speckle ◽  
Speckle Correlation

scholarly journals A New Pattern Quality Assessment Criterion and Defocusing Degree Determination of Laser Speckle Correlation Method

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4728
Author(s):  
Wenxin Hu ◽  
Zhipeng Sheng ◽  
Keyu Yan ◽  
Hong Miao ◽  
Yu Fu
Keyword(s):  
Quality Assessment ◽  
Speckle Pattern ◽  
Correlation Method ◽  
Quality Criterion ◽  
Laser Speckle ◽  
Widespread Application ◽  
Speckle Correlation ◽  
Speckle Patterns ◽  
Speckle Size

The laser speckle correlation method has found widespread application for obtaining information from vibrating objects. However, the resolution and accuracy of the laser speckle correlation method as they relate to the defocusing degree have not been analyzed sufficiently. Furthermore, the possible methods for speckle pattern quality assessment and enhancement have not been studied. In this study, the resolution and accuracy of the laser speckle correlation method are analyzed, and it is found that they are affected by the defocusing degree and speckle pattern quality, respectively. A new speckle pattern quality criterion combining the mean intensity gradient and frequency spectrum was proposed, called CMZ. The quality of the speckle pattern is higher when the CMZ is closer to zero. The proposed criterion was verified by simulated speckle patterns and real speckle patterns with different speckle sizes, densities, and gray contrasts. In the experimental setup stage, a suitable defocusing degree can be selected based on the resolution requirement and optimal speckle size, and other experimental parameters can be determined according to the CMZ criterion. Rotation and vibration experiments verified the effectiveness of the laser speckle correlation method and confirmed the reliability of the experiment preparation based on proposed CMZ criterion.

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