Fiber Bragg grating sensors for structural and railway applications

Hwa Yaw Tam, S. Y. Liu, B. O. Guan, W. H. Chung, T. H.T. Chan, L. K. Cheng

Research output: Journal article publicationConference articleAcademic researchpeer-review

41 Citations (Scopus)


Historically, due to the high cost of optical devices, fiber-optics sensor systems were only employed in niche areas where conventional electrical sensors are not suitable. This scenario changed dramatically in the last few years following the explosion of the Internet which caused the rapid expansion of the optical fiber telecommunication industry and substantially driven down the cost of optical components. In recent years, fiber-optic sensors and particularly fiber Bragg grating (FBG) sensors have attracted a lot of interests and are being used in numerous applications. We have conducted several field trials of FBG sensors for railway applications and structural monitoring. About 30 FBG sensors were installed on the rail tracks of Kowloon-Canton Railway Corp. for train identification and speed measurements and the results obtained show that FBG sensors exhibit very good performance and could play a major role in the realization of "Smart Railway". FBG sensors were also installed on Hong Kong's landmark TsingMa Bridge, which is the world longest suspension bridge (2.2 km) that carries both trains and regular road traffic. The trials were carried out with a high-speed (up to 20 kHz) interrogation system based on CCD and also with a interrogation unit that based on scanning optical filter (up to 70 Hz). Forty FBGs sensors were divided into 3 arrays and installed on different parts of the bridge (suspension cable, rocker bearing and truss girders). The objectives of the field trial on the TsingMa Bridge are to monitor the strain of different parts of the bridge under railway load and highway load, and to compare the FBG sensors' performance with conventional resistive strain gauges already installed on the bridge. The measured results show that excellent agreement was obtained between the 2 types of sensors.
Original languageEnglish
Article number12
Pages (from-to)85-97
Number of pages13
JournalProceedings of SPIE - The International Society for Optical Engineering
Issue numberPART 1
Publication statusPublished - 14 Jun 2005
EventAdvanced Sensor Systems and Applications II - Beijing, China
Duration: 8 Nov 200412 Nov 2004

ASJC Scopus subject areas

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


Dive into the research topics of 'Fiber Bragg grating sensors for structural and railway applications'. Together they form a unique fingerprint.

Cite this