介绍了波长编码型光纤传感器高精度解调技术的最新研究进展，所涉及的解调技术能够实现对波长编码型光纤传感单元阵列的亚纳应变级分辨率的测量能力.首先回顾了光纤光栅应变传感技术，分析了高精度光纤应变传感器所选用的敏感元件；然后介绍了前馈式扫频激光线宽压缩技术和闭环轮询式探测技术，详述其理论原理、实现方案、性能指标；最后介绍了基于上述技术实现的高精度光纤应变传感系统实现地壳形变观测的应用实例，为各类高性能光纤传感器的研究与应用提供参考.
This paper introduces the latest progress in the demodulation techniques of high resolution wavelength-coded optical fber sensor, which are applicable to high performance optical fber strain sensor and sensor array with sub-nano strain resolution. This paper frst reviews and discusses the classical FBG strain sensing technique and introduces the optimized sensing elements in high resolution optical fber strain sensing systems; then presents the authors' recent works on demodulation methods for high resolution optical fber sensors, including a feed-forward frequency-swept laser linewidth compression technique and a closed-loop cyclic interrogation technique in detail. Finally, we introduces an implementation of the high resolution optical fber sensors in the observation of crustal deformation, providing an example for other related research and application scenarios.
[1] Kerseya D, Berkoff T, Morey W. Multiplexed fber Bragg grating strainsensorsystem with a fber Fabry-Perot wavelength flter[J]. Optics Letters, 1993, 18(16):1370-1372.
[2] Rao Y J. In-fbre Bragg grating sensors[J]. Measurement science and technology, 1997, 8(4):355-375.
[3] Hill K O, Meltz G. Fiber Bragg grating technology fundamentals andoverview[J]. Journal of Lightwave Technology, 1997, 15(8):1263-1276.
[4] Kersey A, Davis M, Patrick H, et al. Fiber grating sensors[J]. Journal of Lightwave Technology, 1997, 15(8):1442-1463.
[5] Erdogan T. Fiber grating spectra[J]. Journal of Lightwave Technology, 1997, 15(8):1277-1294.
[6] Okamoto K. Fundamentals of optical waveguides[M].[S.l.]:Academic Press, 2006.
[7] 李东明. 干涉型光纤光栅水听器关键技术研究[D]. 杭州:浙江大学,2013.
[8] 廖延彪,黎敏,张敏,等. 光纤传感技术与应用[M]. 北京:清华大学出版社,2009.
[9] Chen J, Liu Q, He Z. Feedforward laser linewidth narrowing scheme using acousto-optic frequency shifter and direct digital synthesizer[J]. Journal of Lightwave Technology, 2019, 37(18):4657-4664.
[10] Chen J, Liu Q, He Z. Time-domain multiplexed high resolution fber optics strain sensing system based on temporal response of fber Fabry-Perot interferometers[J]. Optics Express, 2017, 25(18):21914-21925.
[11] Shank C, Bjorkholm J, Kogelnik H. Tunable distributed-feedback dyelaser[J]. Applied Physics Letters, 1971, 18(9):395-396.
[12] Aflatouni F, Bagheri M, Hashemi H. Design methodology and architecturesto reduce the semiconductor laser phase noise using electrical feedforwardschemes[J]. IEEE Transactions on Microwave Theory and Techniques, 2010, 58(11):3290-3303.
[13] Sala T, Gatti D, Gambetta A. Wide-bandwidth phase lock between a CW laser and a frequency comb based on a feed-forward confguration[J]. Optics Letters, 2012, 37(13):2592-2594.
[14] Garreis R B. 90-degree optical hybrid for coherent receivers[J]. Optical Space Communication, 1991:210-220.
[15] Vankka J, Waltari M, Kosunen M, et al. A direct digital synthesizer withan on-chip D/Aconverter[J]. IEEE Journal of Solid-State Circuits, 1998, 33(2):218-227.
[16] Volder J E. The CORDIC trigonometric computing technique[J]. IRE Transactionson Electronic Computers, 1959, 8(3):330-334.
[17] Drever R, J L, Hall F V K, Hough J, et al. Laser phase and frequency stabilization using an optical resonator[J]. Applied Physics B, 1983, 31(2):97-105.
[18] Black E D. An introduction to Pound-Drever-Hall laser frequency stabilization[J]. American Journal of Physics, 2001, 69(1):79-87.
