Ordinary Illuminating Light Speckle Using Optical Fiber For Surface Deformation Measurement

The paper presents a method for the measurement of surface deformation using an incoherent optical fibre bundle to transmit ordinary illuminating light to the test surface with artificially generated speckle pattern and using a coherent fibre bundle to transmit the generated artificially speckle pattern to photographic film, for recording and analysis. The doubly-exposed speckle pattern is analysis using point-by-point method to measure the surface deformation. The white light speckle measurements have the advantage that there is no need requirement of constant phase difference in producing holograph and laser speckles. We have discovered the relation each other between the speckle dimension, single fibre diameter and the across section size of the coherent fibre bundle using the sinesoide grating frequency analysis. We have also found that the Young's fringes of considerably higher visibility can be obtained while point-by-point analysis of the recorded film is performed in the reflected light field.