Wide-band supercontinuum generation in mid-IR using polarization maintaining chalcogenide photonic quasi-crystal fiber.

Abstract

We report a polarization maintaining chalcogenide (ChG) photonic quasicrystal fiber (PQF) for wide-band mid-IR (MIR) supercontinuum (SC) generation. The numerical demonstration of SC generation in the proposed PQF spans from 2 to 15μm wavelengths for a pulse power of 2kW. Besides, the proposed PQF offers a high birefringence (10-3 to 10-2) from 3.5 to 15μm wavelengths and exhibits a low confinement loss (10-7 to 10-1) for the wavelengths from 2 to 15μm with single mode behavior. The proposed Ge11.5As24Se64.5 PQF is designed with zero dispersion wavelengths (ZDWs) at 4.33 and 4.46μm for X and Y polarized modes within the wavelength range of 2-15μm. The polarized spectral broadening of the continuum is realized for the first time from 2 to 15μm using the proposed PQF with a length of 8mm. Hence, the two orthogonally polarized modes allow the high degree of freedom in tuning the properties of the SC. Thus, the proposed PQF-based SC source is a good candidate for applications such as optical sensing, frequency metrology, and optical tomography.