Polarization-Maintaining Performance of Solid-Core Anti-Resonant Fiber With Nested Circular Tubes in 3 μm Wavelength

Abstract

We present the structural design and polarization-maintaining performance of solid-core anti-resonant fiber with two nested circular tubes in 3 μm wavelength for the first time, to the best of our knowledge. Numerical simulation results indicated that laser fundamental mode could be obtained by filling the specially designed fiber model with materials of different refractive indices to form the completely solid configuration. We calculated the bend loss of fiber to demonstrate the preferable birefringence performance and outstanding light-confining ability. With the structural deformations from resonant tubes, the birefringence coefficient was enhanced significantly from 2 × 10^−5 to 6.93 × 10^−5, which was of great importance in the polarization sensitive systems. In particular, when nested circular tubes were moved to introduce deformations, the confined loss difference in two orthogonal polarizations was calculated more than two orders of magnitude, which was the desirable result to promote the fabrication of the linear polarizer in 3 μm wavelength.