Design for a Single-Polarization Photonic Crystal Fiber Wavelength Splitter Based on Hybrid-Surface Plasmon Resonance

Abstract

A novel single-polarization photonic crystal fiber wavelength splitter based on hybrid-surface plasmon resonance is proposed. A full-vector finite-element method is applied to analyze the guiding properties. Numerical simulations show that the proposed splitter, which is only several hundred microns in length, gives single polarization in the 1.31- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$\mu\hbox{m}$</tex-math></inline-formula> and 1.55- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$\mu\hbox{m}$</tex-math></inline-formula> bands. The loss of the unwanted polarized mode is 102.6 and 245.0 dB/cm in the two aforementioned communication windows, respectively, and the corresponding insertion loss is as low as 3.5 and 1.7 dB/cm, respectively. Moreover, the dependence of the bandwidth on the fiber length is given, and according to that function, the bandwidth can reach 40 nm (1.31- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$\mu\hbox{m}$</tex-math></inline-formula> band) and 100 nm (1.55- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$\mu\hbox{m}$</tex-math></inline-formula> band) when the fiber length is up to 1 mm. Additionally, the tolerances for a realistic fabrication are analyzed. In the last part, we discuss other methods to deal with an anticrossing phenomenon in detail.