Demonstration of CO_2-laser power delivery through chalcogenide-glass fiber with negative-curvature hollow core

Abstract

A technologically simple optical fiber cross-section structure with a negative-curvature hollow-core has been proposed for the delivery of the CO2 laser radiation. The structure was optimized numerically and then realized using Te20As30Se50 (TAS) chalcogenide glass. Guidance of the 10.6 µm СО2-laser radiation through this TAS-glass hollow-core fiber has been demonstrated. The loss at λ=10.6 μm was amounted ~11 dB/m. A resonance behavior of the fiber bend loss as a function of the bend radius has been revealed.

Revolver Hollow Core Optical Fibers

“…However, fiber bending reveals another important feature of RF: the resonance coupling of the hollow core modes with the cladding capillary modes ( Figure 6). For the first time such, the resonant coupling was found by numerical simulation in [15], and then this effect was experimentally investigated in [8,16,45].…”

“…Note, the choice of materials for RFs is largely limited: up to now, RFs have been made of silica glass, chalcogenide glass [15], and organic glass (polymethylmethacrylate) [16]. Waveguiding properties are also influenced by the ratio of the wavelength to the basic geometric dimensions of RF, such asthe diameter of the hollow core D core and the thickness of the capillary walls d. However, this ratio can be optimized for a wavelength of interest during the fiber manufacturing process.…”

“…Nevertheless, the results that were obtained show that silica-based RFs can be used up to vacuum ultraviolet (124 nm) [18]. In the case of RFs that are made of chalcogenide glass, the waveguiding properties of RFs have been demonstrated up to wavelengths~10 µm [15]. THz radiation can also be transmitted in polymethylmethacrylate waveguides that are similar to RFs [16].…”

“…However, this procedure is not necessary in some cases. For example, in [15], the RF was made from chalcogenide glass, which has a high temperature expansion coefficient, and the heat treatment was not carried out to avoid the possible cracking of the preform. …”

“…However, this procedure is not necessary in some cases. For example, in [15], the RF was made from chalcogenide glass, which has a high temperature expansion coefficient, and the heat treatment was not carried out to avoid the possible cracking of the preform. During the fiber drawing process, an excess gas pressure is applied to the capillaries, in order to prevent their collapse under the action of surface tension forces.…”