Fabrication and characterization of multimaterial Ge25Se10Te65/As2S3 chalcogenide fiber with a high value of the numerical aperture

The design and fabrication of a novel multimaterial Ge25Se10Te65/As2S3 chalcogenide glass fiber with ultra-high numerical aperture (NA) by using the rod-in-tube method was reported. The NA of fiber of approximately 2.2 is the maximum NA of step-index chalcogenide fibers obtained experimentally. The Ge25Se10Te65 glass was selected as the core material, and its mechanical and thermal properties were investigated. The optical properties and bending strength were measured to investigate fiber performance. The low bending loss of fiber was demonstrated through a simulation and an experiment. The fundamental dispersion characteristic, effective-mode-area, and nonlinear coefficient of fiber were simulated numerically.