Comparison of Loss in Silica and Chalcogenide Negative Curvature Fibers as the Wavelength Varies

Abstract

We computationally study fiber loss in negative curvature fibers made with silica, As 2 S 3 chalcogenide, and As 2 Se 3 chalcogenide glasses with a fixed core-diameter-to-wavelength ratio of 30. We consider both simple and nested geometries as the transmission wavelength varies. At wavelengths shorter than 4.5 µm, silica negative curvature fibers have a loss that is around or below 10 -1 dB/m and are preferable to chalcogenide fibers. At wavelengths longer than 4.5 µm, it is preferable to use As 2 S 3 chalcogenide or As 2 Se 3 chalcogenide negative curvature fibers since their loss is one or more orders of magnitude lower than the loss of silica negative curvature fibers. With nested negative curvature fibers, chalcogenide fibers have losses that are lower than those of silica fibers at wavelengths larger than 2 µm. However, it is still preferable to use silica nested negative curvature fibers at wavelengths less than 4.5 µm and with a loss around or lower than 10 -1 dB/m due to the fabrication advantages of silica fibers.

Polarization-filtering and polarization-maintaining low-loss negative curvature fibers

“…The two nested resonant tubes in the y-direction are represented by blue rings. The tube diameter, d tube , the core diameter, D core , the wall thickness of the major tube, t, and the minimum gap distance between the cladding tubes, g, are related by the expression: D core = d tube + 2t + 2g for fibers with 6 major tubes [30,[34][35][36]. We calculate the fiber modes and propagation constants using Comsol Multiphysics, a commercial full-vector mode solver based on the finite-element method.…”

“…A higher-order antiresonance implies a thicker tube wall, especially for shorter wavelengths, which makes fabrication easier. Geometries that use tube thicknesses corresponding to the first, second, or third antiresonance have similar minimum losses in the transmission band [34,35].…”

Revolver Hollow Core Optical Fibers

“…Thus, starting at wavelengths >2 µm, the total losses in silica RF begin to be increasingly determined by the material losses of silica glass. It turns out that the optical loss behavior for RFs with simple capillaries in the cladding (( Figure 1a,b) and for RFs with nested capillaries (Figure 1c) is different in the region of high material losses [42]. The optical losses in the nested RF are lower than in RFs with one row of cladding capillaries up to a certain wavelength in the mid IR spectral range.…”

“…Material loss of silica glass changes from 0.1 dB/m to 10 5 dB/m in the wavelength range from 2 µm to 6 µm [42]. Thus, starting at wavelengths >2 µm, the total losses in silica RF begin to be increasingly determined by the material losses of silica glass.…”

Geometry of Chalcogenide Negative Curvature Fibers for CO₂ Laser Transmission

“…The delivery of mid-infrared radiation has also been successfully demonstrated using chalcogenide negative curvature fibers for a CO 2 laser at a wavelength of 10.6 µm [13][14][15]. Previous study shows that chalcogenide glass should be used for wavelength larger than 4.5 µm [16]. The relative simplicity of the negative curvature structure could enable the fabrication of fiber devices for mid-IR applications using non-silica glasses, such as chalcogenide [13][14][15].…”