Multiple-parameter fiber sensing based on fiber lasers and fiber Bragg gratings

9^th International Conference on Optics, Photonics & Lasers

July 02-04, 2018 | Berlin, Germany

Shien Kuei Liaw

National Taiwan University of Science and Technology, Taiwan

Posters & Accepted Abstracts: J Laser Opt Photonics

Abstract :

Fiber sensing has been extensively used in several areas such as petroleum mining and vibration sensing, pressure, acceleration and flow, and strain and temperature measurement in composite materials for aircraft and helicopter structures. Among the current fiber optic sensing systems, fiber Bragg grating (FBG)-based sensor may be the most favorable one due to their real-time and remote sensing ability. In a fiber-laser-based FBG sensing system, the laser cavity forms part of the FBG sensor. Therefore, the changes in the FBG physical condition can be detected directly through the laser wavelength. The fiber laser sensor dynamic range is equivalent to the cavity length. In this talk, several multi-wavelength fiber sensing systems will be designed and demonstrated. The light source may be a semiconductor optical amplifier (SOA) or Erbium-doped fiber amplifier (EDFA). To construct a linear-cavity laser array, the rear cavity end may be a 2Ã?Â?2 fiber loop mirror or 3-port optical circulator; while the front cavity end may be a FBG. The characteristics and sensor performance of laser output for different sensing distances will be evaluated. The result shows that this SOA-based laser sensor array possesses a dynamic sensing distance of up to 40 km, while stress, temperature, strain and pressure detection were successfully achieved. An array waveguide grating integrated with an optical switch is also used to construct a multiple fiber sensing array with good sensing performance and high reliability.