[Design and Optimization of Surface Plasmon Resonance Sensor Based on Side Polished Single-Mode Fiber].

Fiber-coupling surface Plasmon resonance sensor has attractive advantages of information transmission such as small volume, anti-electric magnetic field interference, and online real-time remote detection. In order to improve the performance of the sensor, the effect of the residual fiber thickness and the silver film thickness to the sensitivity of the sensor and the depth of the resonance peaks and full width ar half maximum (FWHM) are analyzed respectively. The results show that the increasing fiber residual thickness weakens the SPR phenomenon, and that the increasing silver film thickness widens the resonance peak, while the sensitivity of the sensor does not change monotonously. Through the integration of refractive index sensing sensitivity and full width at half maximum, figure of merit is presented and regarded as the optimized objective. The optimal design is achieved in the case of the fiber residual thickness for 66. 5 µm, and the silver film thickness for 50 nm. The optimized design with the figure of merit of 98. 67 is expected to be applied in the bio-chemical sensing and analysis.

[Spectra modulated surface plasmon resonance sensor based on side polished multi-mode optical fiber].

Surface plasmon resonance, which utilizes the resonance of optical evanescent wave with the metal surface plasmon wave, has been developed into a high sensitivity, rapid, label-less measurement method for chemical and biological analysis. In order to improve the spectral sensitivity in refractive index for a side polished fiber surface plasmon resonance sensor, the whole cladding layer and part of core of a multimode fiber was polished off. Additionally, an extra chrome layer with relatively high refractive index was coated on the polished zone before a gold film. The results showed that the sensor can measure the refractive index range from 1.333 to 1. 431 RIU, with the average spectral sensitivity of 4.11 x 10(3) nm RIU(-1), which is better than the reported results. Especially, in the refractive index range of 1. 417 1. 431 RIU, the sensitivity reaches to 1.09 x 10(4) nm RIU(-1). The minimum resolution of approximately 3.6 x 10(-5) RIU was estimated by a combination analysis with the sensor sensitivity and stability. The superiorities possessed by the proposed sensor in high sensitivity, wide detection range, small size and good stability and reproducibility, etc., make it a good candidate for food testing, environmental monitoring, biomedical testing and other related fields.

[Performance of wavelength modulation surface plasmon resonance biosensor].

Surface plasmon resonance (SPR) is a rapid, label-free, high-precision technique of biological sensing and analysis. The investigation on the characteristics of provides theoretical basis and instructions for the applications of SPR A Kretschmann-structure surface plasmon resonance (SPR) biosensor based on wavelength modulation was developed, and also its sensing performances in the bulk solution was investigated. Measurements with different concentrations of bulk ethanol and ethylene glycol solutions show that the resonant wavelength shows a low sensitivity, but a higher linear response to the change in refractive index (RI), when RI is relatively smaller. With increasing refractive index , the sensitivity of resonance wavelength to changes in the refractive index increases. In the refractive index range of 1. 407 0-1. 430 RIU, sensitivity reaches to 11 487 nm RIU-1. The sensor resonance wavelength stability is 0. 213 8 nm, and the minimum resolution of refractive index approaches to 10-6 RIU. The advantages of the surface plasmon resonance sensor developed here results in simple operation, high sensitivity, wide detection range, low resolution, makes it an important candidate in chemical and biological sensing.

Optically tunable chirped fiber Bragg grating.

This work presents an optically tunable chirped fiber Bragg grating (CFBG). The CFBG is obtained by a side-polished fiber Bragg grating (SPFBG) whose thickness of the residual cladding layer in the polished area (D(RC)) varies with position along the length of the grating, which is coated with a photoresponsive liquid crystal (LC) overlay. The reflection spectrum of the CFBG is tuned by refractive index (RI) modulation, which comes from the phase transition of the overlaid photoresponsive LC under ultraviolet (UV) light irradiation. The broadening in the reflection spectrum and corresponding shift in the central wavelength are observed with UV light irradiation density of 0.64mW/mm. During the phase transition of the photoresponsive LC, the RI increase of the overlaid LC leads to the change of the CFBG reflection spectrum and the change is reversible and repeatable. The optically tunable CFBGs have potential use in optical DWDM system and an all-fiber telecommunication system.

[Study on the Eu-containing coordination polymer. I. Structural characterization of Eu (III)-thienyltrifluroacetone-poly (styrene-acrylic acid)].

Three samples (a), (b) and (c) of luminescent Eu-containing copolymer (NaEu(III)-TTA-PSAA) were synthesized through the reaction of copolymer of acrylic acid and styrene (Mw = 3000) with metalorganic complex (NaEu(TTA)4) obtained from Eu and thienyltrifluroacetone. These samples of coordination polymers were characterized by FTIR, UV and XPS, and their composition and structures were determined. The results of electrical conductivity methods and elemental analysis indicated that there were different compositions and structures of these coordination polymers in different pH. The results of elemental analysis also showed that the content of Eu3+ in sample (a), (b) and (c) was 11.89%, 12.55% and 13.41%, respectively.