CO2-laser-induced long-period gratings in graded-index multimode fibers for sensor applications

Lei Su, Kin Seng Chiang, Chao Lu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

27 Citations (Scopus)


Long-period grating (LPG) fabricated in a graded-index multimode fiber (MMF) by deforming the geometry of the fiber periodically with a focused CO2-laser beam is reported. The effects of the grating parameters on the transmission of the grating are investigated. We show that the transmission characteristics of the grating arc similar to those of an MMF subject to periodic microbending. Strong mode couplings take place in the grating when the pitch of the grating is equal to a specific value (∼1 mm), known as the critical spatial period of the fiber. The responses of some fabricated gratings to the axial strain and the change in the surrounding refractive index are measured and good sensitivities are achieved. Such MMF LPGs can be used potentially as physical and chemical sensors.
Original languageEnglish
Pages (from-to)190-192
Number of pages3
JournalIEEE Photonics Technology Letters
Issue number1
Publication statusPublished - 1 Dec 2006
Externally publishedYes


  • Chemical sensor
  • Long-period grating (LPG)
  • Multimode fiber (MMF)
  • Strain sensor

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Atomic and Molecular Physics, and Optics
  • Physics and Astronomy (miscellaneous)


Dive into the research topics of 'CO2-laser-induced long-period gratings in graded-index multimode fibers for sensor applications'. Together they form a unique fingerprint.

Cite this