A new type of THz photonic crystal fiber with super-flattened dispersion

Abstract

A new type of THz photonic crystal fiber with super-flattened dispersion and air hole varying cladding is designed in this paper. Its dispersion properties are analyzed by using the finite-difference time-domain (FDTD) method. The results show that the new THz photonic crystal fiber is better than THz photonic crystal fiber with air hole unarying cladding in controlling the dispersion, and that the new THz photonic crystal fiber has the flattened dispersion when the third ring diameter has the same value as the forth ring diameter. When the air hole diameters are d1=0.85d4, d2=0.95d4,d3=d4(d1,d2,d3,d4 are the diameters of air hole from the inter clad to the outer clad), the new THz photonic crystal fiber can have almost super-flattened dispersion at a level of -0.1±0.3 ps/(nm·km), a good ability to restrict the THz wave and a low loss in a wavelength reange between 60 μm and 65 μm.