Modeling the Dispersion and Nonlinearity of the Hollow ZBLAN Microfiber in the Mid-Infrared Region

ZBLAN fiber is widely used in the mid-infrared band, mainly for spectrum, sensing, laser power transmission, fiber laser, and amplifier. By tapering the soft glass optical fiber such as ZBLAN fiber to microfiber, the waveguide behavior can be tailored in the mid-IR spectral range to realize large normal waveguide dispersion. However, the tunability of the dispersion and nonlinearity must be further explored. Because hollow waveguides offer various compelling features, we proposed and designed a hollow ZBLAN microfiber to adjust the dispersion and nonlinearity and numerically investigated the fundamental propagation characteristics of hollow ZBLAN microfibers within the 2-5 mu m mid-infrared spectral range. The three-layer-dielectric circular waveguide structure was modeled, and the waveguide dispersion, group velocity dispersion, and nonlinearity coefficients of hollow ZBLAN microfibers were investigated. The numerical results showed that the hollow ZBLAN microfiber exhibits broadband dispersion compensation and tunable nonlinear coefficient when its geometry is tailored. The proposed method can be used to manipulate the propagation characteristics of the microfiber in the mid-infrared regime, and the results provide a reference for the design of high-performance mid-infrared optoelectronic devices.