Experimental study on the speckle noise in optical fiber and its application to the sensor

Speckle noise in an optical fiber is one of the most annoying problems in treating coherent light. Also, it is influenced by mismatch in the optical axis and deformation due to an imposed load on the fiber. In this study, in order to apply the optical fiber to a sensor, the speckle noise pattern was measured by using the digital signal processing technique (DSPT) along with the digital logic operation technique (DLOT). As a result, the characterization of the speckle noise pattern was made possible, even when the distortion of fiber was changed microscopically.