Photonic crystal fiber modulator based on surface plasmon resonance

Abstract

In this paper, a photonic crystal fiber (PCF) modulator based on surface plasmon resonance (SPR) is proposed. Two optical functional materials, liquid crystal and magnetic fluid, were filled in the air holes with aurum film of PCF to excite SPR. After applying electric and magnetic fields, the effective refractive index of the SPP (surface plasmon polaritons) mode in PCF would be changed by liquid crystals and magnetic fluids, which affected the resonance wavelength and loss peak. The modulation feasibility of the structure was verified by the full vector finite element method. The results show that the proposed modulator can independently realize electro-optical and magneto-optical modulation with a characteristic of wavelength tunability. At the wavelength of 1450 nm, the electro-optic modulation voltage reaches 2.5 V, and the extinction ratio reaches a maximum of 46.11 dB/mm. Only 0.43 mm length is required to meet communication requirements. At the same time, the magnetic field sensitivity and extinction ratio of the modulator reach 17.82 pm/Oe and 25.18 dB/mm, respectively, at the wavelength of 1682 nm. The modulator has the characteristics of high extinction ratio, low modulator voltage and miniaturization, which can be used in optical fiber transmission systems that need to be integrated.