Study Transmission Laser on Short Distance by Singlemode Fiber Optic Based on Standard Deviation of Intensity

Abstract

The relation between standard deviation of spot laser and thenumber of turns and the variety of bending diameters of single modefiber optic has been studied in this work at short distance (10) cm fromlaser source. The single-mode fiber optic made from silica and turnsover different diameter cylinders (3, 5 and l0) cm in one to ten turns.We capture image for spot laser for each turn by using digital cameraconnected by computer to calculate the standard deviation fromalgorithm program. The diode laser was used with wavelength (630-680) nm, power (5 mW). The conclusion that increasing the bendingdiameter led to decrease standard deviation. Increasing number of turnsled to decrease the standard deviation ofred color of spot laser. Threecolor bands (red, green and blue) were shown in our work. In first turn,the red color was dominant. Increasing number of turns led to put thegreen and blue colors be dominant. The best diameter of optical fiber isthe high bending diameter (10) cm, where we get high coherence.