Analysis of a wavelength-tunable D-shaped photonic crystal fiber filter with broad bandwidth

This paper has designed a D-shaped photonic crystal fiber filter based on surface plasmon resonance. The single-polarization filtering performance is analyzed systematically by the finite element method. It is found that the structural optimization process will modify the refractive index of the fundamental mode and the surface plasmon polarization mode, which results in a shift of the resonance wavelength. The proposed filter is able to indicate the wavelength-tunable function in the ranges of 1250-1350 nm and 1550-1750 nm by two methods. Moreover, at the communication windows of 1310 nm and 1550 nm, the corresponding filtering bandwidths are 170 and 550 nm, respectively. The flow chart of filter preparation reported in the study is promising for use in the field of optical devices. (C) 2021 Optical Society of America