An experimental study on the relationships between the speckle noise and the deformation of optical fiber

In order to apply a speckle noise in optical fiber to sensor, the relationship between speckle noise pattern and deformation of the optical fiber was investigated. In the experiment. the He-Ne gas laser as light source, and the multi-mode and graded index optical fiber (quartz) were used. The image through the optical fiber was observed with respect to the movement of optical axis and the distortion of optical fiber. In addition. in order to extract the speckle noise pattern from the optical image, the digital image measuring system was applied. And, for both quantitative extraction and characterization of the speckle noise pattern variation, the digital logic operating technique was applied.