Efficient Light Coupling and Propagation in Fiber Optic Systems

Abstract

This study explores the propagation of light in optical fibers, focusing on the fundamental principles and practical implications for fiber optic technologies. By analyzing the wave equation, the research demonstrates that light propagates as cylindrical waves within the fiber, contrasting with spherical waves in free space. The study highlights the significance of Gaussian beams, particularly from helium-neon lasers, finding a beam waist radius of approximately 12.6 μm and its position about 1.25 μm from the focus. These parameters are critical for optimizing laser beam coupling into the fiber. The research also measures the light transit time through a 100-meter fiber, revealing a light speed of approximately 2×108 m/sec, which is influenced by the fiber's refractive index. Additionally, the relationship between diode laser output power and injection current was investigated, demonstrating a linear correlation crucial for practical applications. The findings emphasize the importance of accurate measurements and configuration in improving fiber optic communication and laser performance. This comprehensive analysis provides valuable insights into the design and optimization of optical fiber systems, contributing to advancements in communication and laser technologies.