Analysis of the optical and thermal characteristics of a hexagonally shaped six-core fiber for kilowatt-class amplifiers

The optical and thermal properties of six-core fibers with hexagonal geometry are numerically investigated to model high-power fiber amplifiers. Numerical simulations with finite element methods are conducted for two core/cladding/coating dimensions: 10/250/380 μm and 25/400/550 μm. To ensure independent amplification in all six channels, we define the conditions required for isolated-mode operation by adjusting core-to-core spacing. We then calculate the temperature distribution in these design