Li Zhihong, Chen Tao, Zhang Zhaogang, Zhou Yanming, Li Dan, Xie Zhong
Appl Opt. 2016 Feb 20;55(6):1470-80. doi: 10.1364/AO.55.001470.
In this study, we propose and investigate a novel grating-assisted surface plasmon resonance (SPR) platform based on a silver coated long period fiber grating having a photosensitive cladding (C-LPFG). We show that the SPR mode is transited from the higher EH mode with an effective refractive index (ERI) close to that of the surrounding refractive index (SRI) and is highly sensitive to a change in the SRI. Compared with a conventional SPR sensor, a much higher sensitivity is obtained for the novel C-LPFG-based SPR sensor. The sensitivity can be further improved by reducing the fiber diameter. The numerical results show that the highest local sensitivity, which can be as high as ∼4900 nm/RIU, and the corresponding resolution of ∼2.04×10(-6) RIU are achieved for the reduced silver coated C-LPFG sensor. Moreover, the Q-factor and the figure of merit exhibit better characteristics than those of the conventional LPFG-based SPR sensor. Our findings provide insight into the C-LPFG-based SPR platform being a potentially important area to explore for biochemical sensing.
在本研究中，我们提出并研究了一种基于具有光敏包层的镀银长周期光纤光栅（C-LPFG）的新型光栅辅助表面等离子体共振（SPR）平台。我们表明，SPR模式从具有接近周围折射率（SRI）的有效折射率（ERI）的较高EH模式转变，并且对SRI的变化高度敏感。与传统的SPR传感器相比，新型基于C-LPFG的SPR传感器具有更高的灵敏度。通过减小光纤直径可以进一步提高灵敏度。数值结果表明，对于减小的镀银C-LPFG传感器，实现了高达约4900 nm/RIU的最高局部灵敏度以及约2.04×10(-6) RIU的相应分辨率。此外，品质因数和优值表现出比传统基于LPFG的SPR传感器更好的特性。我们的研究结果为基于C-LPFG的SPR平台作为生物化学传感的潜在重要探索领域提供了见解。
