Correlation technique using of-the-shelf CW DFB laser for interrogation of fiber optic sensors
Keywords:Fiber Bragg Gratings, sensors, multiplexing
The paper presents a simple fiber-optic sensor technique based on methods of correlation optical time domain reflectometry. A correlation reflectometry technique can measure distribution of reflection coefficient along the optical fiber by calculating the correlation function between a probe optical signal (reference) and the signal returned back due to reflections or/and back-scattering from the fiber under the test. To obtain the best sensor performance, the probe signal power should be a truly random function of time. As an optical source we use a free-running DFB laser diode operating in a continuous wave regime without any external modulation. To generate the probe test signal, laser light is passed through an interferometer with an optical path difference much longer than the coherence length of the laser light. The light intensity at the interferometer output has a truly random fluctuations and its auto correlation function is suitable for correlation optical reflectometry. We present results of experimental verification of the techniques in different sensor configurations. Multipoint sensor using very low reflective fiber Bragg gratings with reflectivity of 0.01% printed in a long SMF-28 optical fiber was demonstrated.
Simon Pevec and Denis Donlagić, Multiparameter fiber-optic sensors: a review, Optical Engineering 58 (2019) 072009.
A. May-Alarcon, E.A. Kusin, R.A. Vazquez-Sanchez et al., Sensor laser de fibra optica con una cavidad de 8.6 km formada por dos rejillas de Bragg usadas como espejos, Revista Mexicana de Fisica 48 (2002) 434.
Li Xia et al., TDM Interrogation of Identical Weak FBGs Network Based on Delayed Laser Pulses Differential Detection, IEEE Photonics Journal 10 (2018) 6802308
D. J. F. Cooper et al., Time-division multiplexing of large serial ﬁber-optic Bragg grating sensor
arrays, Applied Optics 40 (2001) 2643.
Z. Luo et.al., A time - and wavelength-division multiplexing sensor network with ultra-weak fiber bragg gratings, Optics Express 21 (2013) 22799.
J. Wang et al., Interrogation of a large-capacity densely spaced fiber Bragg grating array using chaos-based incoherent-optical frequency domain reflectometry, Optics Letters 44 (2019) 5202.
M. Nazarathyet al., Realtime long range complementary correlation optical time domain reflectometer, Journal of Lightwave Technology 7 (1989) 24.
N. Takeuchi et al, Random modulation CW lidar, Applied Optics 22, (1983) 1382.
Y. Wang et al., Chaotic correlation optical time domain reflectometer utilizing laser diode, IEEE Photonics Technology Letters 20, (2008) 1636.
A. Arias et al., Phase-sensitive correlation optical time-domain reflectometer using quantum phase noise of laser light, Optics Express 23 (2015) 30347.
Jorge H. López et.al., Multipoint Refractometer Based on Combined Correlation and Frequency Multiplexing, IEEE Ptotonics Technology Letters 29 (2017) 1479
Copyright (c) 2021 Mikhail Shlyagin, Luis Antonio Arias, Jorge Humberto Lopez Rivera
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