-
-
[show abstract]
[hide abstract]
ABSTRACT: A parallel multiplexed temperature sensor scheme using a Bragg grating-based fiber laser approach has been developed and evaluated. Multiple laser cavities were formed as the active gain media of the system using a common broadband chirped fiber Bragg grating (CFBG) and several normal FBGs, which were used as optical feedback elements, in conjunction with different lengths of erbium-doped fibers (EDFs). These gain media were externally pumped by light from a 1480-nm laser diode (LD) through a 1480-nm 1 times 4 splitter. Normal FBGs were used as the wavelength-selective and sensing elements of the laser system. Simultaneous laser action at three different wavelengths corresponding to channels 1, 3, and 4, respectively, was obtained using this scheme. The temperature was measured over the range from room temperature (27 degC) to a maximum of 540 degC, which shows the potential of the scheme for quasi-distributed sensor applications
IEEE Sensors Journal 09/2006; · 1.52 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A novel Bragg grating-based fiber-optic laser probe for temperature sensing using erbium-doped fiber as the active gain medium is reported. The combination of a chirped grating and a normal grating was used to form the laser cavity to achieve temperature-tunable laser action over a wide measurement range. The laser probe used a metal sheath to enhance its mechanical strength and contain the normal grating at the sensing point. The temperature dependence of the wavelength of the laser probe gives a sensitivity of 12.01 pm/°C and a repeatability of ±1.7°C from room temperature to 300°C.
IEEE Photonics Technology Letters 02/2004; · 2.19 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Reports the development of a simple referenced liquid-crystal fibre-optic switch. The referencing is achieved via time multiplexing. The sensor has a response time of 5 s, within a 1 degrees C threshold. This threshold temperature may be altered by exchanging probes containing different liquid crystals in the probe head.
Journal of Physics E Scientific Instruments 11/2000; 21(8):817.
-
[show abstract]
[hide abstract]
ABSTRACT: A simple ‘‘proof‐of‐principle’’ demonstration of the use of fluorescent optical fibers in an optical level sensor has been shown and results obtained over a sensing range of several hundred millimeters to an acceptable degree of accuracy for a low‐cost, simple domestic or industrial device.
Review of Scientific Instruments 01/1991; · 1.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The development and calibration of a visible LED-pumped,
photoluminescent optical-fiber sensor to measure temperature using the
crystal alexandrite is reported. Utilizing the dependence of the
fluorescent decay time on temperature, this instrument is accurate to
±1°C over a range 20-150°C, with a response time of 1 s
IEEE Transactions on Instrumentation and Measurement 10/1988; · 1.21 Impact Factor
-
-
-
[show abstract]
[hide abstract]
ABSTRACT: Fibre optic laser-based sensor systems show considerable advantages over passive sensors using spontaneous emissioj, due to the higher optical power delivered by the sensor and the narrow linewidth associated with the measurand. In recent years, the use of Fibre Bragg Grating (FBG)-based laser systems has enabled compact systems to be developed and recent work by the authors and others has shown the conditions under which high temperature operation of such fibre lasers can occur. As a result, a number of sensor schemes are possible, and this work will report on results taken on the measurement of both temperature and strain over the range from 22 to 500[degrees]C and 0 to 1200 respectively. The systems involved in such measurements use fibre lasers configured with a conventional uniform FBG coupled to a chirped grating to form the laser cavity, enclosed by a length of Er[sup]3+-doped fibre as the gain medium and pumped by 1480 nm laser source. In this way components derived from the optical communications field can readily be applied to optical instrumentation and sensing. The perturbation of the uniform grating by the measurand is used as the primary mechanism in these sensor systems and the availability of chirped gratings with a particularly broad bandwith, coupled with specially fabricated photosensitive fibre into which the FBGs are written has enabled a uniquely large measurement range of temperature, together with the determination of strain, to be achieved. This then offers the possibilities of measurements in situations which otherwise are difficult, e.g. furnace linings and aero-engines. The potential for multiplexing using such a system, to enable a broader range of probes to be utilized will be discussed.
