Beyond Two-Octave Coherent OAM Supercontinuum Generation in Air-Core As₂S₃ Ring Fiber

Abstract

In this work, we designed and simulated a novel air-core As2S3 ring fiber that supports orbital angular momentum (OAM) modes. By optimizing the structure parameters of the designed fiber to effectively tailor its chromatic dispersion, a near-zero flat dispersion profile with a total of <; ±30 ps/nm/km variation over 3380-nm bandwidth from 2025 nm to 5405 nm is achieved for OAM1,1 mode. After launching a 100-fs 70-kW hyperbolic secant pulse into an 8-mm air-core As2S3 ring fiber, a light-carrying OAM supercontinuum is numerically formed beyond two-octave range, covering 5717nm bandwidth from 1182 nm to 6897 nm at -30dB. Furthermore, the generated supercontinuum is highly coherent across the whole spectral range. This can serve as an effective manner to expand the spectral coverage of the OAM beams for various applications.

Keywords

• Supercontinuum generation
• optical vortex
• nonlinear optics
• ring fiber