[1] X ZHANG, C WANG, T ZHENG et al. Wearable optical fiber sensors in medical monitoring applications: a review. Sensors, 23, 6671(2023).

[2] B KAUR, S KUMAR, B K KAUSHIK. Novel wearable optical sensors for vital health monitoring systems—a review. Biosensors, 13, 181(2023).

[3] J A KIM, D J WALES, G Z YANG. Optical spectroscopy for in vivo medical diagnosis—a review of the state of the art and future perspectives. Prog Biomed Eng, 2, 042001(2020).

[4] C WANG, L ZENG, Z LI et al. Review of optical fibre probes for enhanced Raman sensing. J Raman Spectroscopy, 48, 1040-1055(2017).

[5] R KUSCHMIERZ, E SCHARF, D F ORTEGÓN-GONZÁLEZ et al. Ultra-thin 3D lensless fiber endoscopy using diffractive optical elements and deep neural networks. Light Adv Manuf, 2, 1(2021).

[6] J SUN, B YANG, N KOUKOURAKIS et al. AI-driven projection tomography with multicore fibre-optic cell rotation. Nat Commun, 15, 147(2024).

[7] S PARK, Y GUO, X JIA et al. One-step optogenetics with multifunctional flexible polymer fibers. Nat Neurosci, 20, 612-619(2017).

[8] S CHEN, Z WANG, K XIAO et al. A comprehensive review of optical fiber technologies in optogenetics and their prospective developments in future clinical therapies. Opt Laser Technol, 179, 111332(2024).

[9] K ZOLNACZ, R STEPHAN, J DREMEL et al. Multicore fiber with thermally expanded cores for increased collection efficiency in endoscopic imaging. Light Adv Manuf, 5, 1(2024).

[10] J SUN, R KUSCHMIERZ, O KATZ et al. Lensless fiber endomicroscopy in biomedicine. PhotoniX, 5, 18(2024).

[11] E CORDERO. In-vivo Raman spectroscopy: from basics to applications. J Biomed Opt, 23, 1(2018).

[14] [14] GAN L, ZHOU J, SHEN L, et al. Ultralow crosstalk fused taper type faninfanout devices f multice fibers[C]Optical Fiber Communication Conference (OFC) 2019, 2019: Th3D.3.

[15] C N LIU, S C LEI, Y C HSU et al. New scheme of microlens for high-yield laser coupling to PMF by calibrated glass coating. IEEE Photonics Technol Lett, 30, 1075-1078(2018).

[16] S M YEH, Y K LU, S Y HUANG et al. A novel scheme of lensed fiber employing a quadrangular-pyramid-shaped fiber endface for coupling between high-power laser diodes and single-mode fibers. J Light Technol, 22, 1374-1379(2004).

[17] Y WEI, Y SU, C LIU et al. Segmented detection SPR sensor based on seven-core fiber. Opt Express, 25, 21841-21850(2017).

[18] Z ZHU, L LIU, Z LIU et al. Surface-plasmon-resonance-based optical-fiber temperature sensor with high sensitivity and high figure of merit. Opt Lett, 42, 2948(2017).

[19] X YANG, D LORENSER, R A MCLAUGHLIN et al. Imaging deep skeletal muscle structure using a high-sensitivity ultrathin side-viewing optical coherence tomography needle probe. Biomed Opt Express, 5, 136(2014).

[20] H Y CHOI, S Y RYU, J NA et al. Single-body lensed photonic crystal fibers as side-viewing probes for optical imaging systems. Opt Lett, 33, 34(2008).

[21] Shitai YANG, Dawei CHEN, Shaochen DUAN. Diagonal core reflection coupler on multi-core fiber. Acta Optica Sinica, 43, 1306001(2023).

[22] X TANG, Y ZHANG, Y ZHANG et al. All-fiber active tractor beam generator and its application. J Light Technol, 38, 1420-1426(2020).

[23] S YANG, H WANG, T YUAN et al. Highly sensitive bending sensor based on multicore optical fiber with diagonal cores reflector at the fiber tip. J Light Technol, 40, 6030-6036(2022).

[24] S YANG, H WANG, L MENG et al. Dual-FBG and F-P cavity compound optical fiber sensor for simultaneous measurement of bending, temperature and strain. J Light Technol, 41, 1582-1588(2023).

[25] H DENG, Y ZHANG, T YUAN et al. Fiber-based optical gun for particle shooting. ACS Photonics, 4, 642-648(2017).

[26] X ZHANG, T YUAN, S YANG et al. Optical trajectory transport device based on a three-core fiber. Opt Laser Technol, 140, 107076(2021).

[27] C MA, D WANG, J WANG et al. A compact sensor capable of temperature, strain, torsion and curvature measuring. J Light Technol, 40, 4896-4902(2022).

[28] C ZHU, H ZHAO, P WANG et al. Enhanced flat-top band-rejection filter based on reflective helical long-period fiber gratings. IEEE Photonics Technol Lett, 29, 964-966(2017).

[29] X M XI, G K L WONG, M H FROSZ et al. Orbital-angular-momentum-preserving helical Bloch modes in twisted photonic crystal fiber. Optica, 1, 165(2014).

[30] [30] WANG X. Highly sensitive flexible surface plasmon resonance sens based on sidepolishing helicalce fiber: theetical analysis experimental demonstration[J]. Adv Photonics Res , 2021, 2(2): 2000054.

[31] Y LIU, A ZHOU, L YUAN. Gelatin-coated michelson interferometric humidity sensor based on a multicore fiber with helical structure. J Light Technol, 37, 2452-2457(2019).

[32] V I KOPP. Chiral fiber gratings. Science, 305, 75-78(2004).

[33] G SHVETS, S TRENDAFILOV, V I KOPP et al. Polarization properties of chiral fiber gratings. Appl Opt, 11, 074007(2009).

[34] G K L WONG, M S KANG, H W LEE et al. Excitation of orbital angular momentum resonances in helically twisted photonic crystal fiber. Science, 337, 446-449(2012).

[35] C FU, S LIU, Y WANG et al. High-order orbital angular momentum mode generator based on twisted photonic crystal fiber. Opt Lett, 43, 1786(2018).

[36] Y ZHANG, Z BAI, C FU et al. Polarization-independent orbital angular momentum generator based on a chiral fiber grating. Opt Lett, 44, 61(2019).

[37] H ZHAO, P WANG, T YAMAKAWA et al. All-fiber second-order orbital angular momentum generator based on a single-helix helical fiber grating. Opt Lett, 44, 5370(2019).

[38] X ZHAO, Y LIU, Z LIU et al. Wavelength tunable OAM mode converters based on chiral long-period gratings. IEEE Photonics Technol Lett, 32, 1519-1522(2020).

[39] H ZHAO, Z ZHANG, M ZHANG et al. Broadband flat-top second-order OAM mode converter based on a phase-modulated helical long-period fiber grating. Opt Express, 29, 29518(2021).

[40] R A BERGH, G KOTLER, H J SHAW. Single-mode fibre optic directional coupler. Electron Lett, 16, 260-261(1980).

[41] M H CORDARO, D L RODE, T S BARRY et al. Precision fabrication of D-shaped single-mode optical fibers by in Situ monitoring. J Light Technol, 12, 1524-1531(1994).

[42] M CONSALES, M PISCO, A CUSANO. Lab-on-fiber technology: a new avenue for optical nanosensors. Photonic Sens, 2, 289-314(2012).

[43] Z FU, D LIU, W HAN. Waveguide coupled polymer micro-ring resonator in a D-shaped fiber. J Light Technol, 42, 835-840(2024).

[44] J WANG, L PEI, Z LI et al. Wavelength-switchable polarization filter based on graphene-coated d-shaped photonic crystal fiber. Plasmonics, 19, 2363-2370(2024).

[45] R MA, L WAN, X LIU et al. Polarization in D-shaped fiber modulated by magneto-optical dichroism of magnetic fluid. Chin Opt Lett, 18, 010601(2020).

[46] S WANG, M SU, L TANG et al. Graphene-coated D-shaped terahertz fiber modulator. Front Phys, 11, 1202839(2023).

[47] C FENG, L MENG, H WANG et al. Multi-channel seven-core fiber SPR sensor without temperature and channel crosstalk. J Light Technol, 42, 2144-2150(2024).

[48] [48] DEL Villar I, GONZALEZVALENCIA E, KWIETNIEWSKI N, et al. Nanophotonic crystal Dshaped fiber devices f labelfree biosensing at the attomolar limit of detection[J]. Adv Sci , 2024, 11(35): 2310118.

[49] Z DING, G WANG, F XU. Highly birefringent D-shaped micro-fiber device for high-repetition-rate-difference single-cavity dual-comb generation. J Light Technol, 42, 3877-3883(2024).

[50] L MENG, G CHEN, D WANG et al. Thermal diffusion technique for in-fiber discrete waveguide manipulation and modification: a tutorial. J Light Technol, 39, 3638-3653(2021).

[51] M KIHARA, M MATSUMOTO, T HAIBARA et al. Characteristics of thermally expanded core fiber. J Light Technol, 14, 2209-2214(1996).

[52] K SHIRAISHI, T YANAGI, Y AIZAWA et al. Fiber-embedded in-line isolator. J Light Technol, 9, 430-435(1991).

[53] X SHEN, B DAI, Y XING et al. Manufacturing a long-period grating with periodic thermal diffusion technology on high-NA fiber and its application as a high-temperature sensor. Sensors, 18, 1475(2018).

[54] S W JEON, K H SONG, K T KIM et al. Polarization-insensitive wideband OSNR monitoring using thermally expanded core fiber. IEEE Photonics Technol Lett, 23, 1421-1423(2011).

[55] I H SHIN. Novel color combiner composed of red, green, and blue laser diodes and a thermally expanded core fiber waveguide. Opt Eng, 50, 094005(2011).

[56] X ZHOU, Z CHEN, H CHEN et al. Mode field adaptation between single-mode fiber and large mode area fiber by thermally expanded core technique. Opt Laser Technol, 47, 72-75(2013).

[57] L MENG, T JU, L YUAN. A coaxial dual-waveguide fiber coupler. J Light Technol, 41, 6059-6064(2023).

[58] L Z MENG, L B YUAN. Thermal diffusion coupling mechanism and its application of discrete waveguide. Acta Physica Sinica, 72, 246601(2023).

[59] L MENG, H WANG, Q XIA et al. In-fiber thermally diffused coupler and fiber Bragg grating inscribed in twin-core fiber for sensitivity-enhanced vector bending sensing. Photonic Sens, 13, 230310(2023).

[60] H WANG, L MENG, Q XIA et al. 3-D parallel fiber Bragg gratings bending sensor based on single-channel measurement. IEEE Sens J, 23, 7599-7607(2023).

[61] L MENG, L YUAN. A multi-core fiber coupler without a central core. Opt Laser Technol, 174, 110582(2024).