摘要
We study all-optical sensing characteristics based on long-range surface plasmon resonance in a four-layered metal-dielectric structure immersed in the liquid to be measured. The resonance peaks in the reflection angle spectra depend on different refractive indices from 1.30 to 1.38, which are calculated and compared in three typical wavelengths of 532, 632.8 and 780 nm, respectively. Compared with 532 nm, the incident light of 780 nm results in an unstable sensing stability, but the resolution enhances two times. The sensitivity of this refractive index sensor at an incident angle of 45° is about 236.7 nm/RIU which uses 532-nm laser as the light source.
We study all-optical sensing characteristics based on long-range surface plasmon resonance in a four-layered metal-dielectric structure immersed in the liquid to be measured. The resonance peaks in the reflection angle spectra depend on different refractive indices from 1.30 to 1.38, which are calculated and compared in three typical wavelengths of 532, 632.8 and 780 nm, respectively. Compared with 532 nm, the incident light of 780 nm results in an unstable sensing stability, but the resolution enhances two times. The sensitivity of this refractive index sensor at an incident angle of 45° is about 236.7 nm/RIU which uses 532-nm laser as the light source.
基金
The authors thank the support from National Key Laboratory of Tunable Laser Technology, National Natural Science Foundation of China （NSFC） （No. 61078006 and No. 61275066）, and National Key Technology Research and Development Program of the Ministry of Science and Technology of China （No. 2012BAF14BII）.
