The Bending Effect of Single-Mode Optical Fiber at Long Distance from Laser Source on the Spot Laser

Abstract

The bending effect on coherent light in the single mode optical fiber was studied. In this work single mode optical fiber made from silica and turn over cylinders with different diameters (3, 5 and 10) cm to obtain variable bending diameter of fiber was used. Also, diode laser with wavelength (630-680) nm and max. power (5) mw was used as laser source. The image of spot laser for each turn was captured by digital camera connected with computer and at constant long distance (247) cm from laser source.
From our results, we concluded that the area of spot laser increases with increasing the bending diameter of optical fiber and increase the intensity of spot laser. Increasing the number of turns of optical fiber led to decrease the area of spot laser and decrease the intensity of spot laser. So the fiber with bending diameter (10) cm is the best than the two other fibers. In obtaining region of constant area of spot laser, ie. no. of red point constant.