Design of three layered step index fiber for femtosecond pulse delivery at 1550 nm wavelength

Abstract

This paper presents the design and numerical analysis of a step index three-layered fiber optimized for singlemode operation at a wavelength of 1550 nm. The fiber exhibits an extraordinary mode area, measuring 2020 μm², enabling the delivery of ultra-short pulses without distortion. We have used the Transfer Matrix Method for analysis and the Split-Step Fourier Method to solve the nonlinear Schrödinger equation. The study also incorporates considerations for Raman scattering response and self-steepening phenomena in the analysis, enhancing the comprehensive understanding of the proposed step index three-layered fiber for single-mode operation. Demonstrating the propagation of 100-fs pulses with a peak power of 57.7 kW over a 3.4 m length, the fiber maintains a dispersion length-to-nonlinear length ratio of 1 to ensure pulse fidelity. This research offers insights into designing high-performance optical fibers for efficient and distortion-free pulse transmission in ultra-fast laser applications.