Design and numerical modeling of chalcogenide parabolic‐core waveguide for on‐chip supercontinuum generation extending from near‐IR region to mid‐IR region

Abstract

We present the design and computational examination of a waveguide structure with a parabolic core, implemented in AsSe₂ chalcogenide glass. This structure aims to generate a mid‐infrared (mid‐IR) supercontinuum (SC) spectrum, covering the wavelength range of 1.4−7.6 µm. It includes molecular fingerprint region as well as earth's atmospheric transparent window. A pulsed laser providing pulses of peak power of 250 W and pulse width of 200 fs at 2 µm was considered as the pump. The results illustrate that the broadband SC spectrum can be achieved in a short (~8 mm) waveguide pumped with commercially available fiber laser at 2 µm. The novelty of this work lies in the generation of a mid‐IR SC spectrum using a parabolic‐core waveguide pumped in the normal dispersion region, which has not been investigated earlier. This design is crucial as the fabricated rectangular waveguide does not remain rectangular after laser postprocessing but becomes similar to the proposed parabolic design.