A Novel WDM Component Based on a Three-Core Photonic Crystal Fiber

A novel 1.31/1.55 mu m wavelength-division demultiplexer based on a three-core photonic crystal fiber is proposed. The fiber is composed of a large central core and two up-doped cores with different core sizes. The large core is realized by the omission of seven airholes and the insertion of a down-doped rod in the center of fiber. The effective indexes of the two small cores are index matched with the large core at the wavelength of 1.31 and 1.55 mum, respectively. Therefore, wavelength dependent coupling is realized in the three-core optical fiber. Numerical investigation demonstrates that crosstalk lower than -30 dB and polarization-dependent loss lower than 0.1 dB can be realized in one such fiber with a length of 22 mm.