A low-cost submicrolinear incremental encoder based on 3 × 3 fiber-optic directional coupler

H. W. Chow, Chow Norbert Cheung, Wei Jin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)


A high-precision displacement sensor has been developed for short-distance measurement with the interferometric method. This sensor uses a 3×3 fiber-optic directional coupler and a high-coherence laser source with 1550-nm wavelength to produce two interference patterns. A Lissajous figure is generated based on these two patterns. The change in displacement can be obtained after signal comparing and processing. Low cost and high precision are the main advantages of this sensor. Two signal-processing approaches are presented for displacement measurement.
Original languageEnglish
Article number5443850
Pages (from-to)1624-1633
Number of pages10
JournalIEEE Transactions on Instrumentation and Measurement
Issue number6
Publication statusPublished - 1 Jun 2010


  • Coupler
  • Displacement measurement
  • Laser measurement applications
  • Optical fiber interference
  • Optical interferometry

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Instrumentation

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