Comparative Analysis of Single-Core and Double-Core Optical Fibers

This work presents a detailed comparative study of single-core and concentric double-core optical fibers, highlighting their potential advantages for telecommunication applications. Using theoretical and numerical analysis, we examine key parameters including numerical aperture, acceptance angle, V-number, mode capacity, guided power fraction, and radial profiles of the fundamental mode. The double-core fiber exhibits a higher numerical aperture of 0.095 and an acceptance angle of 27.1°, compared to 0.078 and 19.6° for the single-core fiber, enabling more efficient light capture. The normalized frequency parameter (V-number) increases from 6.37 in the single-core fiber to 10.4 in the double-core design, resulting in a total of 54 guided modes versus 20 in the single-core fiber. Radial analysis shows that the fundamental mode is primarily confined within the inner core, with partial extension into the outer core. This distribution facilitates controlled modal coupling and flexible power management, which can be beneficial for multimode transmission or high-power applications. Although the guided power fraction remains 100% in both fiber types, the dual-core structure significantly reduces mode leakage and enhances confinement efficiency, highlighting its potential for robust signal transmission. The comparative results suggest that concentric double-core fibers provide a practical approach to increasing mode diversity and improving light confinement without introducing excessive complexity in fiber fabrication. The dual-core design also aligns with the requirements of advanced telecommunication strategies such as space-division multiplexing, where efficient distribution of multiple spatial channels is essential. Moreover, the dual-core architecture serves as a foundation for further optimization, including tailored core spacing, refractive index engineering, and controlled inter-core coupling, to maximize transmission capacity and signal stability. Overall, the findings demonstrate that double-core fibers offer clear advantages in terms of mode management, power confinement, and flexibility for high-capacity optical systems. These results provide valuable insights for future experimental studies and the development of next-generation multimode and high-performance fiber designs.