{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T15:34:34Z","timestamp":1777995274705,"version":"3.51.4"},"reference-count":63,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,1,4]],"date-time":"2021-01-04T00:00:00Z","timestamp":1609718400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"the National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61905016"],"award-info":[{"award-number":["61905016"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"the Key Projects of the National Natural Science Foundation of China","award":["61735002"],"award-info":[{"award-number":["61735002"]}]},{"name":"the Key Projects of the National Natural Science Foundation of China","award":["51535002"],"award-info":[{"award-number":["51535002"]}]},{"name":"the Beijing Information Science and Technology University Teachers Supplement and Support Program (2019\u20132021)","award":["5029011103"],"award-info":[{"award-number":["5029011103"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Due to their flexible structure and excellent optical characteristics hollow-core photonic crystal fibers (HC-PCFs) are used in many fields, such as active optical devices, communications, and optical fiber sensing. In this paper, to analyze the characteristics of HC-PCFs, we carried out finite element analysis and analyzed the design for the band gap cladding structure of HC-PCFs. First, the characteristics of HC19-1550 and HC-1550-02 in the C-band were simulated. Subsequently, the structural optimization of the seven-cell HC-1550-02 and variations in characteristics of the optimized HC-1550-02 in the wavelength range 1250\u20131850 nm were investigated. The simulation results revealed that the optimal number of cladding layers is eight, the optimal core radius is 1.8 times the spacing of adjacent air holes, and the optimal-relative thickness of the core quartz-ring is 2.0. In addition, the low confinement loss bandwidth of the optimized structure is 225 nm. Under the transmission bandwidth of the optimized structure, the core optical power is above 98%, the confinement loss is below 9.0 \u00d7 10\u22123 dB\/m, the variation range of the effective mode field area does not exceed 10 \u03bcm2, and the relative sensitivity is above 0.9570. The designed sensor exhibits an ultra-high relative sensitivity and almost zero confinement loss, making it highly suitable for high-sensitivity gas or liquid sensing.<\/jats:p>","DOI":"10.3390\/s21010284","type":"journal-article","created":{"date-parts":[[2021,1,4]],"date-time":"2021-01-04T08:35:19Z","timestamp":1609749319000},"page":"284","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Characteristic Analysis and Structural Design of Hollow-Core Photonic Crystal Fibers with Band Gap Cladding Structures"],"prefix":"10.3390","volume":"21","author":[{"given":"Bowei","family":"Wan","sequence":"first","affiliation":[{"name":"Beijing Laboratory of Optical Fiber Sensing and System, Beijing Information Science and Technology University, Beijing 100016, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lianqing","family":"Zhu","sequence":"additional","affiliation":[{"name":"Beijing Laboratory of Optical Fiber Sensing and System, Beijing Information Science and Technology University, Beijing 100016, China"},{"name":"School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xin","family":"Ma","sequence":"additional","affiliation":[{"name":"School of Instrument Science and Optoelectronic Engineering, BeiHang University, Beijing 100191, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tianshu","family":"Li","sequence":"additional","affiliation":[{"name":"School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jian","family":"Zhang","sequence":"additional","affiliation":[{"name":"Beijing Laboratory of Optical Fiber Sensing and System, Beijing Information Science and Technology University, Beijing 100016, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2059","DOI":"10.1103\/PhysRevLett.58.2059","article-title":"Inhibited spontaneous emission in solid-state electronics","volume":"58","author":"Yablonovitch","year":"1987","journal-title":"Phys. Rev. Lett."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1038\/35013024","article-title":"Large-Scale synthesis of a silicon photonic crystal with a complete three-dimensional bandgap near 1.5 micrometres","volume":"405","author":"Blanco","year":"2000","journal-title":"Nature"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"484","DOI":"10.1364\/OL.22.000484","article-title":"All-Silica single-mode optical fiber with photonic crystal cladding: Errata","volume":"22","author":"Knight","year":"1997","journal-title":"Opt. Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/j.spmi.2018.02.023","article-title":"Estimation of photonic band gap in the hollow core cylindrical multilayer structure","volume":"116","author":"Chourasia","year":"2018","journal-title":"Superlattices Microstruct."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1476","DOI":"10.1126\/science.282.5393.1476","article-title":"Photonic band gap guidance in optical fibers","volume":"282","author":"Knight","year":"1998","journal-title":"Science"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1364\/OPEX.13.000236","article-title":"Ultimate low loss of hollow-core photonic crystal fibres","volume":"13","author":"Roberts","year":"2005","journal-title":"Opt. Express"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.optcom.2006.04.019","article-title":"All-Solid silica-based photonic crystal fibers","volume":"266","author":"Chen","year":"2006","journal-title":"Opt. Commun."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"666","DOI":"10.1002\/lapl.201010039","article-title":"Supercontinuum generation up to 2.5 \u03bcm in photonic crystal fiber made of lead\u2013bismuth\u2013galate glass","volume":"7","author":"Buczynski","year":"2010","journal-title":"Laser Phys. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"25232","DOI":"10.1364\/OE.18.025232","article-title":"Ultrafast nonlinear optofluidics in selectively liquid-filled photonic crystal fibers","volume":"18","author":"Vieweg","year":"2010","journal-title":"Opt. Express"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"126338","DOI":"10.1016\/j.optcom.2020.126338","article-title":"Controllable frequency conversion in the coupled time-modulated cavities with phase delay","volume":"476","author":"Chu","year":"2020","journal-title":"Opt. Commun."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1805","DOI":"10.1007\/s11468-016-0448-2","article-title":"Temperature sensor based on hollow fiber filled with Graphene\u2013Ag composite nanowire and liquid","volume":"12","author":"Yang","year":"2016","journal-title":"Plasmonics"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"094209","DOI":"10.1088\/1674-1056\/ab327a","article-title":"Refractive index sensor based on high-order surface plasmon resonance in gold nanofilm coated photonic crystal fiber","volume":"28","author":"Fan","year":"2019","journal-title":"Chin. Phys. B"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Li, T., Zhu, L., Yang, X., Lou, X., and Yu, L. (2020). A Refractive index sensor based on H-shaped photonic crystal fibers coated with Ag\u2013Graphene layers. Sensors, 20.","DOI":"10.3390\/s20030741"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2828","DOI":"10.1038\/s41467-018-05225-1","article-title":"Hollow-Core conjoined-tube negative-curvature fibre with ultralow loss","volume":"9","author":"Gao","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"20291","DOI":"10.1109\/ACCESS.2018.2817577","article-title":"Theoretical analysis of a 750-nm bandwidth hollow-core ring photonic crystal fiber with a graded structure for transporting 38 orbital angular momentum modes","volume":"6","author":"Jia","year":"2018","journal-title":"IEEE Access"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5199","DOI":"10.1109\/JLT.2019.2930075","article-title":"Plasmonic nodeless hollow-core photonic crystal fibers for in-fiber polarizers","volume":"37","author":"Li","year":"2019","journal-title":"J. Lightw. Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.optcom.2019.02.028","article-title":"Low-Loss hollow-core photonic bandgap fiber with isolated anti-resonance layer","volume":"441","author":"Gao","year":"2019","journal-title":"Opt. Commun."},{"key":"ref_18","first-page":"91","article-title":"Analytical formulation for the bend loss in single-ring hollow-core photonic crystal fibers","volume":"2","author":"Frosz","year":"2017","journal-title":"Photonics Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"035104","DOI":"10.1088\/1612-202X\/aa9c03","article-title":"Design and analysis of a modified segmented cladding fiber with parabolic-profile core","volume":"15","author":"Ma","year":"2018","journal-title":"Laser Phys. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3795","DOI":"10.1364\/OL.38.003795","article-title":"Low-Temperature sensitivity periodically tapered photonic crystal-fiber-based refractometer","volume":"38","author":"Wang","year":"2013","journal-title":"Opt. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"14074","DOI":"10.1364\/OE.21.014074","article-title":"Fast response in-line gas sensor using C-type fiber and Ge-doped ring defect photonic crystal fiber","volume":"21","author":"Kassani","year":"2013","journal-title":"Opt. Express"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"24894","DOI":"10.1364\/OE.22.024894","article-title":"Towards high sensitivity gas detection with hollow-core photonic bandgap fibers","volume":"22","author":"Yang","year":"2014","journal-title":"Opt. Express"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"6767","DOI":"10.1038\/ncomms7767","article-title":"Ultra-Sensitive all-fibre photothermal spectroscopy with large dynamic range","volume":"6","author":"Jin","year":"2015","journal-title":"Nat. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"31568","DOI":"10.1364\/OE.25.031568","article-title":"Distributed gas sensing with optical fibre photothermal interferometry","volume":"25","author":"Lin","year":"2017","journal-title":"Opt. Express"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2887","DOI":"10.1109\/JLT.2017.2705229","article-title":"Hollow-Core fiber-based high finesse resonating cavity for high sensitivity gas detection","volume":"35","author":"Tan","year":"2017","journal-title":"J. Lightw. Technol."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Quintero, S.M.M., Valente, L.C.G., Paula Gomes, M.S., Silva, H.G., Souza, B.C., and Morikawa, S.R.K. (2018). All-Fiber CO2 sensor using hollow core PCF operating in the 2 \u00b5m region. Sensors, 18.","DOI":"10.3390\/s18124393"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Portosi, V., Laneve, D., Falconi, M.C., and Prudenzano, F. (2019). Advances on photonic crystal fiber sensors and applications. Sensors, 19.","DOI":"10.3390\/s19081892"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.snb.2017.03.007","article-title":"Dual-Point automatic switching intracavity-absorption photonic crystal fiber gas sensor based on mode competition","volume":"247","author":"Zhang","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"23077","DOI":"10.1039\/D0NR04502K","article-title":"Broadband polarization-insensitive and wide-angle solar energy absorber based on tungsten ring-disc array","volume":"12","author":"Yi","year":"2020","journal-title":"Nanoscale"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1016\/j.renene.2020.05.142","article-title":"Ultra-wideband solar absorber based on refractory titanium metal","volume":"158","author":"Yu","year":"2020","journal-title":"Renew. Energy"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"165779","DOI":"10.1016\/j.ijleo.2020.165779","article-title":"Ultra-short and dual-core photonic crystal fiber polarization splitter composed of metal and gallium arsenide","volume":"226","author":"An","year":"2021","journal-title":"Optik"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"7016","DOI":"10.1016\/j.ijleo.2014.08.083","article-title":"Very large mode area optical fiber with complex ring cores","volume":"125","author":"Zhu","year":"2014","journal-title":"Optik"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1364\/OL.22.000961","article-title":"Endlessly single-mode photonic crystal fiber","volume":"22","author":"Birks","year":"1997","journal-title":"Opt. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1879","DOI":"10.1364\/OL.28.001879","article-title":"Modal cutoff and the V parameter in photonic crystal fibers","volume":"28","author":"Mortensen","year":"2003","journal-title":"Opt. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3580","DOI":"10.1109\/JLT.2005.855855","article-title":"Numerical modeling of photonic crystal fibers","volume":"23","author":"Saitoh","year":"2005","journal-title":"J. Lightw. Technol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2544","DOI":"10.1364\/OL.31.002544","article-title":"Power-Weighted dispersion distribution function for characterizing nonlinear properties of long-haul optical transmission links","volume":"31","author":"Wei","year":"2006","journal-title":"Opt. Lett."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.1364\/OE.10.001314","article-title":"Leakage properties of photonic crystal fibers","volume":"10","author":"Ferrarini","year":"2002","journal-title":"Opt. Express"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"394","DOI":"10.1364\/OPEX.12.000394","article-title":"Air-Core photonic band-gap fibers: The impact of surface modes","volume":"12","author":"Saitoh","year":"2004","journal-title":"Opt. Express"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1246","DOI":"10.1109\/LPT.2003.816702","article-title":"The role of confinement loss in highly nonlinear silica holey fibers","volume":"15","author":"Finazzi","year":"2003","journal-title":"IEEE Photon. Technol. Lett."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1006\/jcph.1994.1159","article-title":"A perfectly matched layer for the absorption of electromagnetic waves","volume":"114","author":"Berenger","year":"1994","journal-title":"J. Comput. Phys."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2599","DOI":"10.1364\/OL.43.002599","article-title":"Unique loss characteristics in TE01 modes of conventional photonic bandgap fibers","volume":"43","author":"Kubota","year":"2018","journal-title":"Opt. Lett."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Wheeler, N.V., Petrovich, M.N., Slav\u00edk, R., Baddela, N., Numkam, E., Hayes, J.R., Gray, D.R., Poletti, F., and Richardson, D.J. (2012, January 15). Wide-Bandwidth, low-loss, 19-cell hollow core photonic band gap fiber and its potential for low latency data transmission. Proceedings of the National Fiber Optic Engineers Conference, Southampton, UK.","DOI":"10.1364\/NFOEC.2012.PDP5A.2"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"7974","DOI":"10.1364\/OE.14.007974","article-title":"Optimizing the usable bandwidth and loss through core design in realistic hollow-core photonic bandgap fibers","volume":"14","author":"Broderick","year":"2006","journal-title":"Opt. Express"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1142","DOI":"10.1364\/OE.16.001142","article-title":"Control of surface modes in low loss hollow-core photonic bandgap fibers","volume":"16","author":"Broderick","year":"2008","journal-title":"Opt. Express"},{"key":"ref_45","unstructured":"(2020, December 20). Available online: https:\/\/www.thorlabs.us\/thorproduct.cfm?partnumber=HC19-1550."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"9907","DOI":"10.1364\/AO.56.009907","article-title":"Hollow-Fiber-Based surface plasmon resonance sensor with large refractive index detection range and high linearity","volume":"56","author":"Duan","year":"2017","journal-title":"Appl. Opt."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1007\/s10812-009-9174-2","article-title":"Calculation of optical properties of hollow-core photonic crystal fibers","volume":"76","author":"Sotskii","year":"2009","journal-title":"J. Appl. Spectrosc."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Popenda, M., Stawska, H., Mazur, L., Jakubowski, K., Kosolapov, A., Kolyadin, A., and Bere\u015b-Pawlik, E. (2017). Application of negative curvature hollow-core fiber in an optical fiber sensor setup for multiphoton spectroscopy. Sensors, 17.","DOI":"10.3390\/s17102278"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.snb.2009.11.047","article-title":"Highly sensitive photonic crystal fiber based on absorption spectroscopy","volume":"145","author":"Yu","year":"2010","journal-title":"Sens. Actuat. B Chem."},{"key":"ref_50","first-page":"102","article-title":"A novel freeform extrusion fabrication process for producing solid ceramic components with uniform layered radiation drying","volume":"15","author":"Armani","year":"2017","journal-title":"Addit. Manuf."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/s00340-017-6764-1","article-title":"Cladding mode coupling in long-period gratings in index-guided microstructured optical fibers","volume":"123","author":"Sharma","year":"2017","journal-title":"Appl. Phys. B"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1021\/ed039p333","article-title":"The Beer\u2013Lambert law","volume":"39","author":"Swinehart","year":"1962","journal-title":"J. Chem. Educ."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"2426","DOI":"10.1364\/AO.57.002426","article-title":"Terahertz detection of alcohol using a photonic crystal fiber sensor","volume":"57","author":"Sultana","year":"2018","journal-title":"Appl. Opt."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1007\/s13320-016-0323-y","article-title":"Design and optimization of photonic crystal fiber for liquid sensing applications","volume":"6","author":"Arif","year":"2016","journal-title":"Photon. Sens."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1007\/s13320-013-0096-5","article-title":"Design and optimization of index-guiding photonic crystal fiber gas sensor","volume":"3","author":"Olyaee","year":"2013","journal-title":"Photon. Sens."},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Duan, L., Lu, Y., Hao, C., Wu, B., and Yao, J. (2013, January 15\u201318). Gas sensor based on hollow-core photonic crystal fibers with high relative sensitivity. Proceedings of the Asia Pacific Optical Sensors Conference 2013, Wuhan, China.","DOI":"10.1117\/12.2034247"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"372","DOI":"10.1007\/s12200-019-0903-8","article-title":"Chemical sensing through photonic crystal fiber: Sulfuric acid detection","volume":"12","author":"Podder","year":"2019","journal-title":"Front. Optoelectron."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.yofte.2019.05.001","article-title":"Design optimization of a highly sensitive spiral photonic crystal fiber for liquid and chemical sensing applications","volume":"51","author":"Malavika","year":"2019","journal-title":"Opt. Fiber Technol."},{"key":"ref_59","doi-asserted-by":"crossref","unstructured":"Ahmed, S., Mou, J.R., Mollah, M.A., and Debnath, N. (2019, January 28\u201330). Hollow-Core photonic crystal fiber sensor for refractive index sensing. Proceedings of the IEEE International Conference on Telecommunications and Photonics (ICTP), Dhaka, Bangladesh.","DOI":"10.1109\/ICTP48844.2019.9041790"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1016\/j.rinp.2018.10.004","article-title":"Design and analysis of slotted core photonic crystal fiber for gas sensing application","volume":"11","author":"Paul","year":"2018","journal-title":"Results Phys."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"100275","DOI":"10.1016\/j.sbsr.2019.100275","article-title":"Detection of harmful food additives using highly sensitive photonic crystal fiber","volume":"23","author":"Atiqullah","year":"2019","journal-title":"Sens. Bio-Sens. Res."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"100377","DOI":"10.1016\/j.sbsr.2020.100377","article-title":"Hexagonal photonic crystal fiber (H-PCF) based optical sensor with high relative sensitivity and low confinement loss for terahertz (THz) regime","volume":"30","author":"Sen","year":"2020","journal-title":"Sens. Bio-Sens. Res."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1007\/s00339-019-3164-x","article-title":"Design and investigation of PCF-based blood components sensor in terahertz regime","volume":"125","author":"Hossain","year":"2019","journal-title":"Appl. Phys. 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