Discrimination between the refractive index and temperatare by using a sandwiched structure of long-period gratings

Li Yang Shao, Aping Zhang, Jin Hua Yan, Sailing He

Research output: Journal article publicationConference articleAcademic researchpeer-review

1 Citation (Scopus)


We present a novel scheme for simultaneous measurement of the external RI and temperature by using the sandwiched long-period gratings (SLPGs). An LPG pair coupling between the guided mode and the low-order cladding mode acts a temperature reference element, and another LPG in-between coupling with the higher-order cladding mode performances an RI sensor. The period and length of the paired LPG (with a center to center distance 47.5mm) are 643 μm and 22.5mm,respectively, and those of LPG in-between are chosen to be 428 μm and 23mm, respectively. The experimental results show that the RI sensitivities of a paired LPG coupling with the third order cladding mode is -6.71 nm/R.I.U (refractive index unit), and the sensitivity of the LPG in between coupling with the ninth order cladding mode is -27.77 nm/R.I.U. The temperature sensitivities of these LPGs are -0.315nm/° C and-0.337nm/° C, respectively.
Original languageEnglish
Article number60191S
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume6019 I
Publication statusPublished - 1 Dec 2005
Externally publishedYes
EventPassive Components and Fiber-based Devices II - Shanghai, China
Duration: 7 Nov 200510 Nov 2005


  • Fiber optic sensors
  • Long-period gratings
  • Mech-Zehnder interferometers
  • Refractive-index sensor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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