Physics – Optics
Scientific paper
Apr 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aipc.1236..309n&link_type=abstract
INTERNATIONAL CONFERENCE ON ADVANCED PHASE MEASUREMENT METHODS IN OPTICS AND IMAGING. AIP Conference Proceedings, Volume 1236,
Physics
Optics
Fabry-Perot Interferometers, Phase Measurement, Fibre Optic Sensors, Optical Sensors, Signal Processing, Holographic Interferometry, Other Holographic Techniques, Effects Of Atomic Coherence On Propagation, Absorption, And Amplification Of Light, Electromagnetically Induced Transparency And Absorption, Fiber Optics, Sensors, Remote Sensing, Optical Computers, Logic Elements, Interconnects, Switches, Neural Networks
Scientific paper
This paper presents the signal interrogator for fiber optic temperature sensors based on all-fiber miniature Fabry-Perot interferometers that are implemented by creation of the low reflectivity mirrors within optical fiber. This kind of Fabry-Perot interferometer has low finesse and nearly sinusoidal spectral characteristics. Since the optical path length between mirrors depends on refractive index and thereby temperature, change in sensor temperature shifts the sensor's spectral characteristics in wavelength domain. The presented measurement system is composed of the sensing interferometer and signal interrogator that further includes the reference interferometer. The reference interferometer is also an all-fiber interferometer with nearly identical length as sensing interferometer. The wavelength of the signal interrogator optical source was cyclically swept over available wavelength range while both interferometers' spectral responses were simultaneously recorded. The optical path length variation of the sensing interferometer was determined by direct phase difference measurement between both recorded sinusoidal spectral characteristics. This phase difference was directly correlated to the temperature difference between sensing and reference interferometer. Since reference interferometer was situated within the signal integrator its temperature was measured by the reference electrical sensors. Thus the proposed system can provide accurate absolute temperature measurements. In the proposed interrogator we used as an optical source a standard telecommunication DFB diode module with integrated thermo-electric cooler. Standard DFB diode can be shifted in wavelength for abut 2 nm, which allows interrogation of the Fabry-Perot interferometers having free spectral range below 2 nm. In case of an all fiber Fabry-Perot interferometers, this corresponds to interferometers with length that is more than 0.5 mm. Since recorded nearly sinusoidal spectral characteristics include single or few periods including various non idealities, various phase difference measurement algorithms and signal preconditioning methods were investigated. Spectral characteristic phase difference resolution of abut 3.5e-3 rad was achieved in real physical system, witch corresponds to resolution of 0.3 °C in case of 1 mm long sensing and reference interferometer. The estimated absolute accuracy of the system was about 0.5 °C. System was build with only few relatively standard telecommunication optoelectronic components and it is therefore simple to implement and potentially cost effective.
Njegovec Matej
Đonlagic Denis
No associations
LandOfFree
Temperature Measurement Using all Fiber Fabry-Perot Interferometers Based on Phase Measurement Between Reference and Sensing Interferometer Spectral Characteristic does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Temperature Measurement Using all Fiber Fabry-Perot Interferometers Based on Phase Measurement Between Reference and Sensing Interferometer Spectral Characteristic, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Temperature Measurement Using all Fiber Fabry-Perot Interferometers Based on Phase Measurement Between Reference and Sensing Interferometer Spectral Characteristic will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1801966