Bragg grating tuned fiber laser system for measurement of wider range temperature and strain

A Parallel Multiplexed Temperature Sensor System Using Bragg-Grating-Based Fiber Lasers

“…For the active sensors, an output power variation of less than ±1.5 dB was obtained. This is due to the smooth spectrum profile of the CFBG used to form the tunable cavity [14] and the fluorescence spectra of the EDF ∼ 1552-nm wavelength for a 1480-nm pumping.…”

“…The multiplexed laser-based sensor system offers both a higher SNR and a narrow linewidth over conventional passive FBG sensor interrogation schemes. It is important to note that the sensor can be used to measure any parameter that responds to narrowband Bragg grating, e.g., temperature (as demonstrated), strain [14], humidity [6], or chemical parameters [7] using coated FBGs. Indeed, multichannel probes responding to different parameters, e.g., a combined temperature, humidity, and strain sensor, can be created with this scheme (where the temperature data can be used to correct for temperature effects in the other probes, if necessary).…”

“…Murphy et al [8] have reported a silica fiber extrinsic Fabry-Pérot (FP) strain sensor to measure temperatures up to 975 • C. Alavie et al [9] have reported a serial multiplexed sensor system where each laser cavity was formed using an FBG and a broadband mirror, measuring the temperature from 20 • C to 160 • C. Kaddu et al [10] have reported multiplexed optical fiber FP sensor systems to measure temperature and strain over the ranges from 20 • C to 70 • C and from 0 to 400 µε, respectively. Peng et al [11] have reported an FBGbased temperature sensor system using a fiber laser to measure temperature over the range from 0 to 40 • C. A Raman fiber laser probe has also been developed [12] for long-distance remote temperature sensing applications, typically reported for use over the temperature range from 30 to 100 • C. Recently, fiber laser-based sensor systems have been developed to measure temperatures up to 500 • C in a single cavity configuration using a chirped FBG (CFBG) and a normal FBG in [13] and [14]. Additionally, some of the commercial manufacturing technologies are also available for temperature measurement applications [15], [16].…”

Fiber Bragg grating-based multi-wavelength fiber lasers using erbium-doped fiber

“…profile of EDF. [20] Even though the output power variation was small for single-wavelength oscillation, it was rather large (~20 dB) for multi-wavelength oscillation due to the competition among different lasing wavelengths. To investigate the tenability of multi-wavelength Er-doped fiber laser, we utilized the thermal tuning method to control the resonance wavelength of each channel at the single wavelength oscillation.…”

Widely tunable compact erbium-doped fiber ring laser for fiber-optic sensing applications

“…For this reason, the tunable fiber laser system is preferred to ASE as the high spectral brightness of the laser can assure long distance and multiple point interrogation and retain a high spectral resolution, which is determined mainly by the spectral width of laser itself [6]. Erbium (Er)-doped fiber (EDF) is most commonly used in such fiber laser systems, due to the wide availability of optical components operating at those wavelengths which has resulted from the rapid developments in the optical communications industry.…”