Modelling of long-period fibre grating response to refractive index higher than that of cladding

R. Hou, Z. Ghassemlooy, A. Hassan, Chao Lu, K. P. Dowker

Research output: Journal article publicationJournal articleAcademic researchpeer-review

76 Citations (Scopus)


In this paper we introduce a new mathematical model, which can be used to investigate the response of a long-period fibre grating to changes in ambient refractive indices of values both greater and less than that of the cladding. A numerical method to calculate the HE core and cladding modes is presented. The results show that even when the ambient refractive index is higher than that of the cladding, the coupling (resonance) wavelengths experience a measurable shift (a few nm). The result obtained suggests that LPGs coated with a material of higher refractive index than the cladding may be used as index sensors.
Original languageEnglish
Pages (from-to)1709-1713
Number of pages5
JournalMeasurement Science and Technology
Issue number10
Publication statusPublished - 1 Jan 2001
Externally publishedYes


  • Cladding mode
  • Core mode
  • Index sensors
  • Leaky mode
  • Long-period grating

ASJC Scopus subject areas

  • Instrumentation
  • Applied Mathematics

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