Abstract
Background: Materials with features such as high transparency and nonlinearity in a wide range of infrared wavelengths can be used in the manufacture of optical fibers. Amongst the materials that are used in the manufacture of optical fibers, chalcogenide compounds are the key materials in the infrared wavelength range. This paper presents a new hexagonal nanostructured photonic crystal fiber based on chalcogenide glass.
Methods: In this paper, the parameters like chromatic dispersion, confinement loss, effective area of the propagating mode, and the nonlinear coefficient are examined and simulated. Each concept is explained and the relations among them are explicated. The core is made up of As2Se3 chalcogenide glass and the cladding network consists of 6 air hole rings embedded in the As2Se3 chalcogenide glass. The most important factors in controlling dispersion in the structure are its geometrical parameters. Results: Simulations are carried out using FDTD method. In this structure, parameters such as dispersion, confinement loss, effective mode area, and nonlinear coefficient are examined and the results are presented. It can be concluded that there are four zero dispersion points at 1.03, 2.27, 9.75 and 14.77 μm. The amount of loss from 1 μm to about 10 μm is almost negligible. Considering that within this range, there are also three zero dispersion points, hence, this makes our proposed N-PCF ideal for supercontinuum generation. Conclusion: By adjusting the structural parameters of the N-PCF, the confinement loss is almost zero over the wavelength range of 1 μm to about 10 μm, 4 zero dispersion points are obtained in the mid-infrared region and the nonlinear coefficient is calculated to be about 35 w-1m-1 at 1.55 μm. It is also concluded that the dispersion is almost flat in the infrared wavelength range. The proposed NPCF with the above characteristics is suitable for supercontinuum generation.Keywords: Chalcogenide glass, high nonlinearity, low confinement loss, nanostructured optical fiber, supercontinuum generation, zero dispersion point.
Graphical Abstract