MEASUREMENT OF CYLINDER DIAMETER BASED ON SUPERPOSITION OF LASER BEAMS

Ryszard Jablonski
Abstract:
Nanotechnology approaching the sphere of quantum mechanics has a lot of limits connected with indirect definition of base, which should be directly related to physical constants and laws. It takes place also in measurements based on superposition of laser beams. Commonly, laser diffraction is considered to be a precise technique to measure dimensions of 3D objects, however, when required accuracy is on the level of 100nm the existing solutions do not fit to engineering applications.
T. Young interpreted the diffraction phenomena as a result of interference of the geometrical wave propagating in free space with “the edge wave”. A. Rubinowicz theoretically proved the possibility of division the Kirchhoff diffraction field into two components: incident wave and reflection wave – created by interaction between primary field and the edge of object. These mathematical considerations are commonly accepted in the scientific world, but were never proved experimentally.
In the paper the diffraction on cylindrical object is considered. Two assumptions for the theory were introduced: extensive source of light and spatial aperture in form of cylinder. The modification of the diffraction equations allowed calculating and plotting the diffraction wave with its components, and it can be considered as the first calculation and graphical representation of the real diffraction process based on Young-Rubinowicz theory.
The obtained results can be used for determination the position of the edge of an object and lead directly to the development of diameter measurement method based on strictly defined physical phenomenon.
Keywords:
laser scanner, diffraction, cylinder diameter
Download:
IMEKO-TC14-2014-28.pdf
DOI:
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Event details
IMEKO TC:
TC14
Event name:
TC14 LMPMI Symposium 2014
Title:

11th Symposium on Laser Metrology for Precision Measurement and Inspection in Industry

Place:
Tsukuba, JAPAN
Time:
03 September 2014 - 05 September 2014