MID-IR SUPERCONTINUUM GENERATION IN DISPERSION FLATTENED AS38SE62 CHALCOGENIDE PHOTONIC CRYSTAL FIBER

Abstract

Photonic Crystal Fiber has property of generating SC due to non-linear properties and dispersion. SC has many applications like spectroscopy, hyper spectral microscopy, and spectral tissue imaging, optical coherence tomography, optical metrology, frequency comb generation, spectroscopy, and multiplexing of wavelength bisection. In this report, we discuss about the square core photonic crystal fiber using chalcogenide glass As38Se62 as core and air holes in IR region. The designing and virtual simulation is performed by applying the Modal Analysis segment in the Electromagnetic Wave Frequency Domain (EWFD) in COMSOL Multiphysics® software, which further calculated the eigenvalue problem for the Maxwell’s electromagnetic equations by an approach of vectorial finite element method (FEM). The design contains a core and a cladding. In this design, the cladding contains circular air holes whereas the core consists of square chalcogenide glass. As core matter, chalcogenide material As38Se62 was used because non-linear index of refraction that is two to three orders of magnitude higher than silicon dioxide. we observe that, at pump wavelength 3.5 m, the nonlinear coefficient is spotted as 1290 W-1 km-1 and effective mode area as 15.3 m 2 . After calculating various useful values noted above, we moved towards our main goal is to generate supercontinuum pulse. We had taken observation of SCG at different peak powers and different fiber lengths by keeping peak pulse at constant value of 50 fs. When performed experiment, we got a maximum broadened pulse of 2000 nm to 12000 nm in 4200 W peak power and 10 mm of fiber length.