Fabrication and Ultra-High Temperature Sensing Characteristics of MgAl2O4 Single-Crystal Fiber Bragg Gratings

doi:10.16553/j.cnki.issn1000-985x.2026.0076

Abstract

Abstract: In order to meet the demand for high-temperature monitoring in extreme high-temperature environments， this paper employs a femtosecond laser line-by-line scanning technique to inscribe high-quality gratings in magnesium aluminate （MgAl₂O₄） single-crystal fibers （MSCF） oriented along the ［100］，［110］， and ［111］ crystallographic directions， respectively. The temperature response characteristics of these gratings were experimentally analyzed over the temperature range from room temperature （20 ℃） to 1 600 ℃. The results indicate that gratings with different crystal orientations exhibit excellent thermal stability and cyclic repeatability， and their central wavelengths show a regular redshift trend with increasing temperature. Benefiting from the intrinsic isotropy of the cubic crystal system， the gratings with three different crystal orientations show similar sensitivities （~39 pm/℃） in the high-temperature region. Through a comparative analysis with the sensing characteristics of sapphire fiber Bragg gratings （SFBGs）， this study further validates the potential advantages of MSCF in high-temperature environments， demonstrating the application potential of MSCF in ultra-high temperature extreme environment sensing scenarios.

Key words: femtosecond laser; MgAl₂O₄ single-crystal fiber; crystal orientation; line-by-line scanning; fiber Bragg grating; high-temperature sensing

CLC Number:

LI Qianhua, WANG Tao, LI Jinshuo, GUO Qi, ZHANG Jian, JIA Zhitai, YU Yongsen. Fabrication and Ultra-High Temperature Sensing Characteristics of MgAl₂O₄ Single-Crystal Fiber Bragg Gratings[J]. Journal of Synthetic Crystals, 2026, 55(7): 1127-1134.

Figures/Tables 8

Fig.1 Schematic diagram of femtosecond laser inscription MSCFBG， with inset photograph of grating inscribed by line-by-line scanning method in ［110］ MSCF

Fig.2 Cross-sectional microscopic images of MSCF with different crystal orientations

Fig.3 Schematic diagram of high-temperature sensing test system， with inset microscopic image of fusion splicing region between MMF and MSCF. BBS： supercontinuum source； OSA： optical spectrum analyzer； OC： multimode fiber coupler

Fig.4 Reflection spectra of MSCFBG with different crystal orientations

Fig.5 Reflection spectral shift curves of MSCFBG with different crystal orientations during heating and cooling processes

Fig.6 Second-order fitting curves of center wavelength of MSCFBG with different crystal orientations versus temperatures

Fig.7 Comparison of fitting curves for relationship between temperature and wavelength of SFBG and MSCFBG with different crystal orientations in different temperature ranges

Table 1 Comparison of temperature sensitivity in different temperature ranges

Temperature/℃	Temperature sensitivity/（pm·℃^-1）
Temperature/℃	SFBG	MSCFBG［100］	MSCFBG［110］	MSCFBG［111］
20~500	19.93	20.38	19.76	19.75
500~1 000	29.89	32.61	32.94	33.80
1 000~1 600	35.74	38.84	38.90	39.30

References 21

[1]	MA S N， XU Y P， PANG Y X， et al. Optical fiber sensors for high-temperature monitoring： a review［J］. Sensors， 2022， 22（15）： 5722. DOI URL
[2]	姚艳玲，代　军，黄春峰. 现代航空发动机温度测试技术发展综述［J］. 航空制造技术， 2015， 58（12）： 103-107.
	YAO Y L， DAI J， HUANG C F. Development for temperature measurement technology in modern aeroengine［J］. Aeronautical Manufacturing Technology， 2015， 58（12）： 103-107 （in Chinese）.
[3]	欧阳可琛，司明浩，邢力，等. 核反应堆内温度测量研究进展与展望［J］. 中国测试， 2025， 21（2）： 1-18.
	OUYANG K C， SI M H， XING L， et al. Research progress and prospect of thermometry applied for in-pile temperature measurement in nuclear reactors［J］. China Measurement & Test， 2025， 21（2）： 1-18 （in Chinese）.
[4]	MIHAILOV S J. Femtosecond laser-induced Bragg gratings in silica-based fibers for harsh environment sensing［J］. APL Photonics， 2023， 8（7）： 071102.
[5]	JOE H E， YUN H， JO S H， et al. A review on optical fiber sensors for environmental monitoring［J］. International Journal of Precision Engineering and Manufacturing-Green Technology， 2018， 5（1）： 173-191. DOI
[6]	HE J， XU B J， XU X Z， et al. Review of femtosecond-laser-inscribed fiber Bragg gratings： fabrication technologies and sensing applications［J］. Photonic Sensors， 2021， 11（2）： 203-226. DOI
[7]	HE J， XU X Z， CHEN R X， et al. Femtosecond laser direct writing of fiber Bragg gratings for multiparameter sensing in extreme environments［J］. APL Photonics， 2025， 10（12）： 120902. DOI URL
[8]	YANG S， HU D， WANG A B. Point-by-point fabrication and characterization of sapphire fiber Bragg gratings［J］. Optics Letters， 2017， 42（20）： 4219-4222. DOI PMID
[9]	SHI G N， SHURTZ R， PICKRELL G， et al. Point-by-point inscribed sapphire parallel fiber Bragg gratings in a fully multimode system for multiplexed high-temperature sensing［J］. Optics Letters， 2022， 47（18）： 4724-4727. DOI PMID
[10]	GUO Q， ZHANG Z D， ZHENG Z M， et al. Parallel-integrated sapphire fiber Bragg gratings probe sensor for high temperature sensing［J］. IEEE Sensors Journal， 2022， 22（6）： 5703-5708. DOI URL
[11]	XU X Z， HE J， LIAO C R， et al. Multi-layer， offset-coupled sapphire fiber Bragg gratings for high-temperature measurements［J］. Optics Letters， 2019， 44（17）： 4211-4214. DOI URL
[12]	HE J， WU J F， XU X Z， et al. Femtosecond laser plane-by-plane inscription of Bragg gratings in sapphire fiber［J］. Journal of Lightwave Technology， 2023， 41（22）： 7014-7020. DOI URL
[13]	GUO Q， LIU S R， PAN X P， et al. Femtosecond laser inscribed helical sapphire fiber Bragg gratings［J］. Optics Letters， 2021， 46（19）： 4836-4839. DOI PMID
[14]	WANG M H， SALTER P S， PAYNE F P， et al. Optimization of single-mode sapphire waveguide Bragg gratings［J］. Journal of Lightwave Technology， 2024， 42（16）： 5629-5638. DOI URL
[15]	XU X Z， HE J， WU J F， et al. Single-mode helical sapphire Bragg grating for high-temperature sensing［J］. Journal of Lightwave Technology， 2025， 43（6）： 2982-2987. DOI URL
[16]	WU J F， XU X Z， HE J， et al. Single-mode sapphire fiber Bragg grating high-temperature sensor［J］. Photonics Research， 2025， 13（12）： 3374-3382. DOI URL
[17]	AKILBEKOV A， KIRYAKOV A， BAUBEKOVA G， et al. Optical characteristics of MgAl₂O₄ single crystals irradiated by 220 MeV Xe ions［J］. Materials， 2023， 16（19）： 6414. DOI URL
[18]	WANG T， WANG H Y， ZHANG J， et al. Design and directional growth of （Mg_1-_x Zn_x）（Al_1-_y Cr_y）₂O₄ single-crystal fibers for high-sensitivity and high-temperature sensing based on lattice doping engineering and acoustic anisotropy［J］. Advanced Functional Materials， 2021， 31（42）： 2103224. DOI URL
[19]	LI Q H， WANG T， LI J S， et al. MgAl₂O₄ single-crystal fiber Bragg gratings for ultra-high temperature sensing［J］. Optics Letters， 2026， 51（7）： 1704-1707. DOI URL
[20]	MIHAILOV S J， GROBNIC D， SMELSER C W. High-temperature multiparameter sensor based on sapphire fiber Bragg gratings［J］. Optics Letters， 2010， 35（16）： 2810-2812. DOI PMID
[21]	CHEN C， ZHANG X Y， YU Y S， et al. Femtosecond laser-inscribed high-order Bragg gratings in large-diameter sapphire fibers for high-temperature and strain sensing［J］. Journal of Lightwave Technology， 2018， 36（16）： 3302-3308. DOI URL

Fabrication and Ultra-High Temperature Sensing Characteristics of MgAl₂O₄ Single-Crystal Fiber Bragg Gratings

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