[1] Kao K C, Hockham G A. Dielectric-fibre surface waveguides for optical frequencies[J]. Proceedings of the Institution of Electrical Engineers, 113, 1151-1158(1966).

[2] Lee B. Review of the present status of optical fiber sensors[J]. Optical Fiber Technology, 9, 57-79(2003).

[3] Hopkins H H, Kapany N S. A flexible fibrescope, using static scanning[J]. Nature, 173, 39-41(1954).

[4] Liu D M, He T, Xu Z J et al. New type of microstructure-fiber distributed acoustic sensing technology and its applications[J]. Journal of Applied Sciences, 38, 296-309(2020).

[5] Juarez J C, Maier E W, Choi K N et al. Distributed fiber-optic intrusion sensor system[J]. Journal of Lightwave Technology, 23, 2081-2087(2005).

[6] Ding Z Y, Wang C H, Liu K et al. Distributed optical fiber sensors based on optical frequency domain reflectometry: a review[J]. Sensors, 18, 1072(2018).

[7] Li P F, Fu C L, Du B et al. High-spatial-resolution strain sensor based on distance compensation and image wavelet denoising method in OFDR[J]. Journal of Lightwave Technology, 39, 6334-6339(2021).

[8] Song J, Li W H, Lu P et al. Long-range high spatial resolution distributed temperature and strain sensing based on optical frequency-domain reflectometry[J]. IEEE Photonics Journal, 6, 6801408(2014).

[9] Kreger S T, Sang A K, Gifford D K et al. Distributed strain and temperature sensing in plastic optical fiber using Rayleigh scatter[J]. Proceedings of SPIE, 7316, 73160A(2009).

[10] Beisenova A, Issatayeva A, Korganbayev S et al. Simultaneous distributed sensing on multiple MgO-doped high scattering fibers by means of scattering-level multiplexing[J]. Journal of Lightwave Technology, 37, 3413-3421(2019).

[11] Meng Y J, Fu C L, Chen L et al. Submillimeter-spatial-resolution φ-OFDR strain sensor using femtosecond laser induced permanent scatters[J]. Optics Letters, 47, 6289-6292(2022).

[12] Canning J. Fibre gratings and devices for sensors and lasers[J]. Laser & Photonics Review, 2, 275-289(2008).

[13] Lu P, Mihailov S J, Coulas D et al. Low-loss random fiber gratings made with an fs-IR laser for distributed fiber sensing[J]. Journal of Lightwave Technology, 37, 4697-4702(2019).

[14] Yan A D, Huang S, Li S et al. Distributed optical fiber sensors with ultrafast laser enhanced Rayleigh backscattering profiles for real-time monitoring of solid oxide fuel cell operations[J]. Scientific Reports, 7, 1-9(2017).

[15] Loranger S, Gagné M, Lambin-Iezzi V et al. Rayleigh scatter based order of magnitude increase in distributed temperature and strain sensing by simple UV exposure of optical fibre[J]. Scientific Reports, 5, 1-7(2015).

[16] Ai F. Research on key technologies and applications of distributed sensing based on discrete reinforced fiber[D](2019).

[17] Du C, Fu C L, Li P F et al. High-spatial-resolution strain sensor based on Rayleigh-scattering-enhanced SMF using direct UV exposure[J]. Journal of Lightwave Technology, 41, 1566-1570(2023).

[18] Meng Y J, Fu C L, Du C et al. Shape sensing using two outer cores of multicore fiber and optical frequency domain reflectometer[J]. Journal of Lightwave Technology, 39, 6624-6630(2021).

[19] Du B, He J, Xu B J et al. High-density weak in-fiber micro-cavity array for distributed high-temperature sensing with millimeter spatial resolution[J]. Journal of Lightwave Technology, 40, 7447-7455(2022).

[20] Lindner E, Hartung A, Hoh D et al. Trends and future of fiber Bragg grating sensing technologies: tailored draw tower gratings (DTGs)[J]. Proceedings of SPIE, 9141, 91410X(2014).

[21] Guo H Y, Tang J G, Li X F et al. On-line writing identical and weak fiber Bragg grating arrays[J]. Chinese Optics Letters, 11, 030602(2013).

[22] Xu B J, He J, Du B et al. Femtosecond laser point-by-point inscription of an ultra-weak fiber Bragg grating array for distributed high-temperature sensing[J]. Optics Express, 29, 32615-32626(2021).

[23] Fan X Y, Koshikiya Y, Ito F. Phase-noise-compensated optical frequency domain reflectometry with measurement range beyond laser coherence length realized using concatenative reference method[J]. Optics Letters, 32, 3227-3229(2007).

[24] Fan X Y, Koshikiya Y, Ito F. Centimeter-level spatial resolution over 40 km realized by bandwidth-division phase-noise-compensated OFDR[J]. Optics Express, 19, 19122-19128(2011).

[25] Ding Z Y, Yao X S, Liu T G et al. Compensation of laser frequency tuning nonlinearity of a long range OFDR using deskew filter[J]. Optics Express, 21, 3826-3834(2013).

[26] Wang B, Fan X Y, Wang S et al. Millimeter-resolution long-range OFDR using ultra-linearly 100 GHz-swept optical source realized by injection-locking technique and cascaded FWM process[J]. Optics Express, 25, 3514-3524(2017).

[27] Luo M M, Liu J F, Tang C J et al. 0.5 mm spatial resolution distributed fiber temperature and strain sensor with position-deviation compensation based on OFDR[J]. Optics Express, 27, 35823-35829(2019).

[28] Feng Y X, Xie W L, Meng Y X et al. High-performance optical frequency-domain reflectometry based on high-order optical phase-locking-assisted chirp optimization[J]. Journal of Lightwave Technology, 38, 6227-6236(2020).

[29] Yin G L, Jiang R, Zhu T. In-fiber auxiliary interferometer to compensate laser nonlinear tuning in simplified OFDR[J]. Journal of Lightwave Technology, 40, 837-843(2022).

[30] Zhong H J, Fu C L, Li P F et al. Distributed high-temperature sensing based on optical frequency domain reflectometry with a standard single-mode fiber[J]. Optics Letters, 47, 882-885(2022).

[31] Qu S. Research on data processing and performance Improvement of distributed optical fiber sensing system based on OFDR[D](2022).

[32] Zhao S Y, Cui J W, Suo L J et al. Performance investigation of OFDR sensing system with a wide strain measurement range[J]. Journal of Lightwave Technology, 37, 3721-3727(2019).

[33] Li W H, Chen L, Bao X Y. Compensation of temperature and strain coefficients due to local birefringence using optical frequency domain reflectometry[J]. Optics Communications, 311, 26-32(2013).

[34] Chiuchiolo A, Palmieri L, Consales M et al. Cryogenic-temperature profiling of high-power superconducting lines using local and distributed optical-fiber sensors[J]. Optics Letters, 40, 4424-4427(2015).

[35] Xin G, Li Z Y, Fan W et al. Distributed sensing technology of high-spatial resolution based on dense ultra-short FBG array with large multiplexing capacity[J]. Optics Express, 25, 28112-28122(2017).

[36] Suo L J, Lei Z K, Zhao S Y et al. Study on sliding-window length based on Rayleigh backscattering spectrum correlation in distributed optical-fiber strain measurement[J]. Optical Fiber Technology, 47, 126-132(2019).

[37] Zhong H J, Fu C L, Wang L J et al. High-spatial-resolution OFDR with single interferometer using self-compensation method[J]. Optics and Lasers in Engineering, 161, 107341(2023).

[38] Song J, Li W H, Lu P et al. Long-range high spatial resolution distributed temperature and strain sensing based on optical frequency-domain reflectometry[J]. IEEE Photonics Journal, 6, 6801408(2014).

[39] Zhao S Y, Cui J W, Wu Z J et al. Accuracy improvement in OFDR-based distributed sensing system by image processing[J]. Optics and Lasers in Engineering, 124, 105824(2020).

[40] Li P F, Fu C L, Zhong H J et al. A nondestructive measurement method of optical fiber young’s modulus based on OFDR[J]. Sensors, 22, 1450(2022).

[41] Duncan R G, Froggatt M E, Kreger S T et al. High-accuracy fiber-optic shape sensing[J]. Proceedings of SPIE, 6530, 487-497(2007).

[42] Moore J P, Rogge M D. Shape sensing using multi-core fiber optic cable and parametric curve solutions[J]. Optics Express, 20, 2967-2973(2012).

[43] Moore J P, Rogge M D. Shape sensing using multi-core fiber optic cable and parametric curve solutions[J]. Optics Express, 20, 2967-2973(2012).

[44] Khan F, Denasi A, Barrera D et al. Multi-core optical fibers with Bragg gratings as shape sensor for flexible medical instruments[J]. IEEE Sensors Journal, 19, 5878-5884(2019).

[45] Barrera D, Madrigal J, Delepine-Lesoille S et al. Multicore optical fiber shape sensors suitable for use under gamma radiation[J]. Optics Express, 27, 29026-29033(2019).

[46] Khan F, Barrera D, Sales S et al. Curvature, twist and pose measurements using fiber Bragg gratings in multi-core fiber: a comparative study between helical and straight core fibers[J]. Sensors and Actuators A: Physical, 317, 112442(2021).

[47] Idrisov R, Floris I, Rothhardt M et al. Characterization and calibration of shape sensors based on multicore optical fibre[J]. Optical Fiber Technology, 61, 102319(2021).

[48] Xiao X Z, Xu B J, Xu X Z et al. Femtosecond laser auto-positioning direct writing of a multicore fiber Bragg grating array for shape sensing[J]. Optics Letters, 47, 758-761(2022).