A simple fiber-optic humidity sensor based on extrinsic Fabry-Perot cavity constructed by cellulose acetate butyrate film

Wei Xu, Wo Bin Huang, Xu Guang Huang, Changyuan Yu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

42 Citations (Scopus)


A fiber-optic relative humidity sensor with an extrinsic micro Fabry-Perot cavity constructed with a thin layer of cellulose acetate butyrate coated on a fiber end is presented. Its operational principle is based on the relative-humidity-dependent wavelength shift of the interference fringes formed by Fresnel reflections from both interfaces of the thin film. Both the experimental and theoretical analyses are investigated in detail. The experimental data for relative humidity ranging from 8.8% to 88.1% are measured in the both humidification and dehumidification processes, which fits the linear equation very well with a value of R2= 0.9946. As observed, it shows a high sensitivity of 0.307 nm/%RH with a high resolution of 0.06%. The time-dependent response of the sensor is estimated. The long term stability of the sensor is also addressed with high precision of ±0.03% over 100 min. The proposed relative humidity sensor has a simple, solid, and compact structure.
Original languageEnglish
Pages (from-to)583-586
Number of pages4
JournalOptical Fiber Technology
Issue number6 PART A
Publication statusPublished - 1 Dec 2013
Externally publishedYes


  • Fabry-Perot
  • Fiber optic
  • Relative humidity
  • Thin-film

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Cite this