Dynamically modulated intensity interrogation scheme using waveguide coupled surface plasmon resonance sensors

Xin Ma, Xinlong Xu, Zheng Zheng, Kun Wang, Yalin Su, Jiangfeng Fan, Rui Zhang, Lusheng Song, Zhiyou Wang, Jinsong Zhu

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


An electro-optically modulated intensity interrogation method based on tunable waveguide coupled surface plasmon resonance sensors has been proposed. It has been theoretically and experimentally demonstrated that the proposed scheme can enable sensitive measurement of measurand variations. By modulating the refractive index in the waveguide layer, this interrogation method yields modulated signal whose amplitude is related to measurand's refractive index. This amplitude modulated signal offers a higher signal to noise ratio and eliminates additive noise in the sensor system. A preliminary investigation using saline buffers with different NaCl concentrations shows a resolution of 2.3 × 10-6 refractive index unit by our approach. Resolution can be controlled by the amplitude of the applied modulation voltage and can be further enhanced by optimizing the device structure or improving the electro-optical (E-O) coefficient of the E-O material. This approach is simple, stable, and promising for low-cost or multi-channel SPR biosensor applications.

Original languageEnglish (US)
Pages (from-to)9-14
Number of pages6
JournalSensors and Actuators, A: Physical
Issue number1
StatePublished - Jan 2010
Externally publishedYes


  • Modulation
  • Optical sensing and sensors
  • Polymer active device
  • Surface plasmon

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering


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