Thermo-optically tunable polarization beam splitter based on selectively gold-filled dual-core photonic crystal fiber with integrated electrodes

Abstract

A thermo-optically tunable polarization beam splitter (PBS) is proposed and numerically studied. The proposed structure is based on a selectively gold-filled dual-core photonic crystal fiber (DC-PCF), which has two internal electrodes for thermo-optical tuning of the operating band of the PBS. A full-vector finite element method is used to analyze the behavior of the main parameters of the proposed device, such as coupling length, coupling length ratio, propagation distance and extinction ratio. Numerical results show that with a small length of 1.890 mm, the coupling length for the two polarization states is not modified in the analyzed temperature range. In addition, the splitter exhibits a coupling length ratio of approximately 1.5 with slightly changes as the temperature increases. The proposed PBS presents a bandwidth of 9 nm, a high extinction ratio of − 83.2 dB and tuning sensitivities of − 67 and $$66\hbox { pm/}^{\circ }\hbox {C}$$ when the internal electrodes are arranged horizontally and vertically, respectively. The DC-PCF based platform with internal electrodes has remarkable advantage such as ease of implementation and high tuning sensitivity, which ensures its potential applications in compact optical systems, optical switching and sensing applications.