Output power distribution of a large core optical fiber

Laser power distributions in the near field of fiber output end were studied experimentally for various launching conditions of an incident laser beam onto its input end. Several different shapes of the power distribution were obtained through a step index (SI) or graded index (GI) fiber having a large core diameter. Conditions to achieve a flat top distribution of the irradiation with a fiber array were examined aiming at its proper use in a medical application such as laser photocoagulation treatments.