A new kind of surface plasmon resonance (SPR) sensor based on silver-coated hollow fiber (HF) structure for the detection of liquids with high refractive index (RI) is presented. Liquid sensed medium with high RI is filled in the hollow core of the HF and its RI can be detected by measuring the transmission spectra of the HF SPR sensor. The designed sensors with different silver thicknesses are fabricated and the transmission spectra for filled liquids with different RI are measured to investigate the performances of the sensors. Theoretical analysis is also carried out to evaluate the performance. The simulation results agree well with the experimental results. Factors that might affect sensitivity and detection accuracy of the sensor are discussed. The highest sensitivity achieved is 6607nm/RIU, which is comparable to the sensitivities of the other reported fiber SPR sensors.

We presented the significant enhancement of the photonic spin Hall effect by taking advantage of long-range surface plasmon resonance (LRSPR). The influence of the thicknesses of metal and dielectric layers in the insulator-metal-insulator structure which supports LRSPR was investigated. Under the optimal parameter setup, the largest transverse separation with a 632.8 nm incident Gaussian beam reaches 7.85 μm, which is much larger than previous reported values.

A long-range surface plasmon resonance (LRSPR) sensor based on dielectric/silver-coated hollow fiber (HF) is proposed. It can detect the refractive index (RI) of sensed liquid filled in the hollow core of the sensor. A HF LRSPR sensor with 90-nm-thick silver layer and 260-nm-thick OC300 layer is fabricated. Experiments are taken to evaluate the performance of the sensor by measuring the transmission spectra. Theoretical analysis based on a ray model is also taken, and the results agree well with the experimental results. The proposed sensor has similar sensitivity but much smaller SPR dip width than the silver-coated HF SPR sensor. Thus figure of merit of the sensor is enhanced approximately five times. The stability of the sensor is also improved because the dielectric layer acts as a protection layer for the damageable silver layer.

A novel high performance optical fiber refractive index (RI) sensor based on the hybrid transverse magnetic (TM) mode of Tamm plasmon polariton (TPP) and surface plasmon polariton (SPP) is proposed. The structure of the sensor is a multi-mode optical fiber with a one dimensional photonic crystal (1 DPC)/metal multi-films outer coated on its fiber core. A simulation study of the proposed sensor is carried out with the geometrical optical model to investigate the performance of the designed sensor with respect to the center wavelength, bilayer period and the thickness of silver layer. Because the lights transmitted in the fiber sensor have much larger incident angles than those in the prism based sensors, the center wavelength of the 1 DPC should shift to longer wavelength. When the coupling between TM-TPP and SPP is stronger, the sensor exhibits better performance because the electromagnetic field of the TPP-SPP hybrid mode is enhanced more in the analyte. Compared to most conventional fiber surface plasmon resonance sensors, the figure of merit of the proposed sensor is much higher while the sensitivity is comparable. The idea of utilizing TPP-SPP hybrid mode for RI sensing in the solid-core optical fiber structure presented in this paper could contribute to the study of the fiber RI sensor based on TPP.

A long-range surface plasmon resonance (LRSPR) sensor based on GK570/Silver coated hollow fiber (HF) with an asymmetric layer structure is proposed. A set of proposed sensors with different layer thicknesses were fabricated by the liquid phase coating method. Both theoretical and experimental analyses were carried out to evaluate the performances of the fabricated sensors, such as sensitivity, figure of merit (FOM) and detection range. The theoretical results based on the ray modal agreed well with the experimental results. The highest experimentally obtained sensitivity and FOM were over 12500 nm/RIU and 150 RIU⁻¹, respectively. The FOM was approximately ten times that of the HF SPR sensor. Moreover, compared to the HF LRSPR sensor with a symmetric layer structure, the proposed sensor has a much larger sensitivity and an approximately double FOM without sacrificing other advantages of the HF LRSPR sensor.

A new optical fiber sensor based on Bloch surface wave was theoretically proposed. An omnidirectional one-dimensional photonic crystal was designed as the multilayer coated on the outer surface of the optical fiber. Taking advantages of the omnidirectional reflection band, there is only surface mode resonance in the transmission spectrum, while guided mode resonance is avoided. The performance of the designed fiber sensor was analyzed theoretically with a ray transmission model. The presented sensor has comparable sensitivity but much higher figure of merit than other fiber sensors. The resolution can reach about 10⁻⁶ RIU or even higher.