Search

This paper combines molybdenum dioxide (MoO2) instead of the gold film with photonic crystal fiber (PCF) for the first time. A novel C-type micro-opening surface plasmon resonance (SPR) optical fiber sensor coated with MoO2 nanofilm is proposed. The polarization and sensing characteristics of the sensor coated with plasma film on the outer surface of the polished optical fiber are numerically analyzed by the finite element method (FEM). The simulation results show that when the plasma material deposited by the optical fiber micro-opening is noble metal gold, the sensor can realize the sensing detection of the refractive index of the analyte from 1.33 to 1.39, and the average wavelength sensitivity in the x-polarization direction reaches 1107 nm/RIU. It is most noteworthy that when the plasma coating material of the optical fiber is replaced by metal oxide MoO2, the sensor can realize the sensing detection of the refractive index of the analyte from 1.31 to 1.37, and the average sensitivity of the x-polarization direction can reach 4821 nm/RIU. By comparison, we can know that the sensor coated with plasma material MoO2 has excellent sensing characteristics. This research is of great scientific significance for expanding the application range of MoO2 materials and promoting the development of photonic crystal fiber sensors coated with new materials. [ABSTRACT FROM AUTHOR]

Fiber optic sensing technology has extensive applications in many fields and demands high sensitivity and cost-effectiveness for sensors. In this study, we propose an ultra-high sensitivity D-type photonic crystal fiber sensor based on MoO 2 nano-film coating to meet this requirement. Firstly, MoO 2 is selected as the plasmonic excitation material. Compared to expensive metals such as Au and Ag, MoO 2 has the characteristics of low cost and charge carrier density, which is suitable for use in optical fiber sensing modules. The sensitivity of the sensor to the external environment can be increased by coating the surface of the optical fiber with MoO 2 nano-film. Then, we use the finite element method to evaluate the performance of the sensor. Numerical simulation results show that the average wavelength sensitivity of the sensor in the x-polarization direction is as high as 24000 nm/RIU when analyzing substances with refractive indices ranging from 1.38 to 1.43. This means that the sensor has a very sensitive response to refractive index changes and can be widely applied to sensing needs in different fields. Overall, the D-type photonic crystal fiber sensor based on MoO 2 nanofilm coating has enormous potential for applications. This sensor can achieve high-sensitivity detection within a specified range of refractive indices, providing new ideas and methods for research and applications in the field of fiber sensing. • MoO 2 was combined with D-type PCF as a plasma exciton material for the first time to form a sensor. • An ultra-high-sensitivity D-type PCF sensor based on MoO 2 nanofilm coating is proposed. • Numerical simulation results show that the refractive index (RI) detection range of the sensor is between 1.38 and 1.43. And the average wavelength sensitivity of the sensor in the x-polarization direction is 24000nm/RIU. • The results demonstrated that MoO 2 can be utilized as an excellent plasma sensing material in optical fiber sensing applications. • This sensor can achieve high-sensitivity detection within a specified range of refractive indices, providing new ideas and methods for research and applications in the field of fiber sensing. [ABSTRACT FROM AUTHOR]

We present a novel D-shaped photonic crystal fiber sensor with double loss peaks based on surface plasmon resonance. The proposed sensor has a lot of better characteristics for refractive index detection compared with single-peak sensor. It is worth noting that the trough of the loss spectrum keeps unchanged as the analyte refractive index increases, which indicates that this sensor is extremely stable. In addition, numerical simulation shows that the average wavelength sensitivity can reach 29,000 nm/RIU and the maximum resolution is as high as 3.45 × 10−5 RIU. Furthermore, the coupling theory between fundamental mode and the surface plasmon polarization (SPP) mode is investigated in this paper. It is found that there is obvious competition between the resonant modes. This study has enlightening significance for us to understand the generation mechanism of polarization-entangled quantum photo source. [ABSTRACT FROM AUTHOR]

A D-shaped photonic crystal fiber sensor based on surface plasmon resonance effect is proposed in this paper. Experimental results show that the D-shaped sensor can perform sensing detection in high or low refractive index regions. In addition, the refractive index of different analytes can be double calibrated by peaks and troughs. For high refractive index region from 1.3621 to 1.4010, the average sensitivity of the peaks and troughs is only 30.0 nm/RIU and 72.7 nm/RIU, respectively. However, in the low refractive index region of 1.3415–1.3468, the average wavelength sensitivity reaches 842.6 nm/RIU. The research in this paper has important reference value and positive scientific significance for exploring novel D-shaped photonic crystal fiber sensors. [ABSTRACT FROM AUTHOR]

Highlight • A high-sensitivity PCF sensor was designed for analyte detection. • This optimized sensor had an excellent linearity and good sensitivity. • The sensitivity within the refractive index range of 1.425–1.45 is 60,611 nm/RIU. • The corresponding minimum detection limit is 1.58 × 10−6 RIU. • The sensitivity within the refractive index range of 1.45–1.46 is 28,000 nm/RIU. • The corresponding minimum detection limit is 2.86 × 10−6 RIU. Abstract A high-sensitivity photonic crystal fiber (PCF) refractive index sensor based on the resonant coupling of core mode and defect mode is studied by the finite element method. The large liquid-filled is placed near to the core for easy coupling with the core mode. The simulation results show that when the refractive index of the analyte is 1.425–1.45 and 1.45–1.46, the average sensitivity is 60,611 and 28,000 nm/RIU respectively, and the corresponding minimum detection limits are 1.58 × 10−6 and 2.86 × 10−6 RIU. [ABSTRACT FROM AUTHOR]

Highlights • The proposed PCF structure is a combination of circular layout and D-shaped. • The gold film is deposited on the polishing surface, the analyte is placed on the outer layer of the D-shaped PCF. • The proposed PCF sensor is feasible for the structural parameters with fabrication tolerance of ±1%. • The proposed sensor easy to fabricate and has high sensitivity. Abstract A high sensitivity D-shaped photonic crystal fiber sensor based on surface plasmon resonance is proposed for refractive index sensing. By using finite element method, the sensing properties of the proposed sensor are investigated. The numerical results show a very high average sensitivity of 14600 nm/RIU with the high resolution of 6.80 × 10−6 RIU for refractive index (RI) of analytes ranging from 1.420 to 1.435. The layout of the air holes is designed to be circular and only two layers in this D-shaped photonic crystal fiber. The metallic gold is used as the surface plasmon resonance activity material, which is deposited on the polishing surface. The analyte is placed on the outer layer of the D-shaped photonic crystal fiber. This D-shaped photonic crystal fiber solves the difficulty of gold-plated film and fill analyte in the holes. The proposed PCF structure is a combination of circular layout and D-shaped, which also leads to the proposed sensor easy to fabricate and has considerable sensitivity. [ABSTRACT FROM AUTHOR]

A three-core photonic crystal fiber refractive index sensor based on the surface plasmon resonance effect is proposed. The three cores of this sensor are symmetrical about the center. The gold film deposited outside the fiber structure makes this sensor contact with the analyte directly, which not only reduces the complexity of the fabrication but also makes the limiting loss very low. The sensing performance of the proposed sensor is investigated by using the finite element method. Numerical results show that the loss spectra of the x-polarized core mode are consistent with the y-polarized core mode. The sensor realizes the sensing detection of the analyte refractive index ranging from 1.37 to 1.42. When the analyte's refractive index is 1.42, the maximum wavelength sensitivity of 2427 nm/RIU for x and y polarization, the corresponding maximum resolution can reach 4.12 × 10−5 RIU. [ABSTRACT FROM AUTHOR]

A dual-polarized microstructure fiber sensor is based on surface plasmon resonance, which is arranged of pentagonal lattice to achieve refractive index sensing in the near-infrared spectrum. The gold nanowire-filled fiber sensor exhibits excellent sensing characteristics and improved transmission properties. Finite element method is used for computational analysis and structural optimization for the fiber sensor. When the refractive index of the analyte range from 1.32 to 1.38, dual-polarizd sensing can be implemented as a self-calibration with wavelengths increasing from 700 to 1200 nm. For the proposed sensor, the highest wavelength sensitivity of 10,286 nm/RIU is exhibited with a sensor resolution of 9.72×10−6 RIU, and the corresponding amplitude sensitivity and figure of merit are as high as 544.0 RIU−1 and 146.9. Moreover, the sensing length of at least 1.14 mm ensures accurate detection of optical signals for proposed sensor. Owing to the above advantages, the proposed sensor is suitable for high integration and high precision sensitivity detection. [ABSTRACT FROM AUTHOR]