Search

In this paper, using the self-made Ge20Sb15Se65 chalcogenide glass as matrix material, we design an infrared octagon dispersion flattened photonic crystal fiber, and the mid-IR dispersion and transmission characteristics are numerically studied using the multipole method. Results show that when we control the duty ratio (d/Λ) in 0.323–0.367, the dispersion and transmission properties in the 3–5 μm range are adjustable. When we set the hole spacing Λ=3.4 μm, hole diameter d=1.1 μm, in the 4.1–4.9 μm band, the fiber dispersion fluctuates between-0.8 ps·nm-1·km-1 and 0.8 ps·nm-1·km-1, and shows single-mode transmission, low loss (LossAeff2) characteristics, thus it is suitable for nonlinear applications in mid-IR band.

Large mode area photonic crystal fibers (PCFs) have attracted much attention, owing to their applications in such as high power delivery, high power fibre amplifiers and fiber lasers. As an ideal candidate for fabricating mid-infrared fibers, chalcogenide glass possesses some unique advantages, such as high refractive indices (2.0-3.5), low photon energies (lower than 350 cm-1), tailorable compositions, and large infrared transmission window(from 1.0 to 20 μm). In this paper, we present a novel type of effectively single-mode chalcogenide glass Ge20Sb15Se65PCF with utra-large mode area as well as small confinement loss (lower than 0.1 dB/m for the fundamental mode, high confinement loss exceeding 2 dB/m for the higher-order mode at 10.6 μm).