Gufeng Hu

Dual-Core Photonic Crystal Fiber for Hydrostatic Pressure Sensing

We propose a novel hydrostatic pressure sensor based on a dual-core photonic crystal fiber (DC-PCF). Two solid fiber cores separated by an air hole in the cross-section lead to two independent waveguides inside the DC-PCF which accompany with mode coupling. The mode coupling of two solid fiber cores of the DC-PCF under different hydrostatic pressure is numerically investigated. A pressure sensing system is proposed and performances of the pressure sensor have been numerically investigated. Our calculations show a hydrostatic pressure sensor based on a 10-cm DC-PCF has a sensing range from 0 to 1000 MPa and a sensitivity of 3.47 pm/MPa.

Bending analysis of a dual-core photonic crystal fiber

A dual-core photonic crystal flber (DC-PCF) is proposed, and bending characteristics of the DC-PCF are investigated. Two flber cores are employed in the cross-section of the DC-PCF, which result in a mode coupling between the two flber cores when the light propagates inside the DC-PCF. The mode coupling between two flber cores of the DC-PCF is sensitive to the directional bending of the DC-PCF which essentially provides a method to achieve bending sensing. A DC-PCF-based bending sensor is proposed by injecting a broadband light into one flber core of the DC-PCF on one side and detecting output spectrum from another flber core of the DC-PCF on the other side. In our simulations, a parabola curve which shows the relationship between the wavelength shift of the transmission spectrum of the DC- PCF-based bending sensor and the bending curvature of the DC-PCF is presented.

Dual-Core Side-Hole Fiber for Pressure Sensing Based on Intensity Detection

We propose a novel dual-core side-hole fiber (DCSHF) for air/hydrostatic pressure sensing. Two large air holes are employed in the cross-section of the DCSHF, which result in a difference of the pressure-induced index changes for two fiber cores. The mode coupling between two fiber cores of the DCSHF is sensitive to the pressure-induced index change which ensures the intensity detection of the DCSHF-based pressure sensor. A segment of DCSHF with a length equal to the coupling length of the mode coupling between two fiber cores is used as a pressure sensor. When the light is injected into the central fiber core of the DCSHF, there is a one-to-one correspondence between the pressure and the output power on the output side of the central fiber core. A pressure sensor based on a typical DCSHF can achieve a pressure measurement range of 27 MPa. DCSHFs with different structure parameters for pressure sensing are investigated.

Pressure/temperature sensor based on a dual-core photonic crystal fiber

A dual-core photonic crystal fiber (DC-PCF) is proposed for pressure/temperature sensing based on the mode coupling of the two fiber cores. The two solid fiber cores separated by an air hole in the cross-section lead to two independent waveguides inside the DC-PCF which accompany with mode coupling. Pressure/temperature sensor based on the DC-PCF is achieved when one fiber core on the input side is connected to a broadband light source and the other fiber core on the output side is connected to an optical spectrum analyzer. A pressure/temperature sensor based on the DC-PCF is designed with a transmission spectrum which is essentially sensitive to the pressure/temperature applied on the DC-PCF. As an example we design a pressure sensor based on a 10-cm DC-PCF for the sensing pressure range from 0 to 1000 MPa with a sensitivity of −3.47 pm/MPa, and a temperature sensor based on a 4-cm DC-PCF for the sensing temperature range from 0 to 1000 °C with a sensitivity of 20.7 pm/ °C. The fiber bending analysis of the DC-PCF is also presented.