-
超窄线宽π相移光纤布拉格光栅在光纤传感领域发挥着重要的作用, 但是这种超窄线宽π相移光纤布拉格光栅对输入光强度非常敏感, 输入光在光栅内部产生光热效应会引起频率移动, 降低了光栅的测量精度, 同时激光器自身的频率漂移也会增大测量误差. 本文提出使用超窄线宽π相移光纤布拉格光栅进行高精度应变测量的方法, 采用单光子调制技术锁定激光频率到38 MHz超窄线宽π相移光纤布拉格光栅, 同时消除了光栅内部光热效应和激光频率起伏对应变测量的影响, 对于0—30 με范围的外部应变实现了测量精度为0.05 με的高精度测量, 该方法在航空航天工程、土木工程、交通工程、能源工程、机械与装备制造等领域具有重要应用价值.
-
关键词:
- 应变测量 /
- π相移光纤布拉格光栅 /
- 频率锁定 /
- 光热效应 /
- 单光子调制
The fiber Bragg grating has the characteristics of anti-electromagnetic interference, electrically passive operation, multi-point sensing, corrosion resistance, and compact size. An ultra-narrow linewidth transmission peak can be formed by introducing a π phase shift at the center of uniform fiber Bragg grating. But this PSFBG with an ultra-narrow linewidth is very sensitive to the input optical intensity. The photothermal effect generated by the input light inside the grating will cause the frequency shift, which will degrade the measurement precision of grating. At the same time, the frequency drift of the laser itself will also increase the measurement error. In this paper, a high-precision strain measurement method is proposed by using the PSFBG with an ultra-narrow linewidth based on the frequency-stabilized laser. The incident laser is attenuated to a single-photon level to eliminate the photothermal effect in the PSFBG. The laser frequency is stabilized to the PSFBG with an ultra-narrow linewidth of 38 MHz by using the single-photon modulation technology. The influence of low-frequency flicker noise is eliminated through 9-kHz high-frequency modulation. The filter bandwidth of lock-in amplifier is 312.5 Hz with the integration time and filter slope of 300 μs and 18 dB, respectively. The signal-to-noise ratio of error signal from the lock-in amplifier is 34. By tuning the resonant cavity length of the laser with the error signal, the output laser frequency is stabilized to the Bragg frequency of the PSFBG with an ultra-narrow linewidth of 38 MHz. The laser frequency fluctuation is limited to 4 MHz within 1000 s. The response sensitivity of Bragg wavelength to external strain in a range of 0 to 30 με is 1.2 pm/με, with a standard error of 0.023 pm/με, and the linear fitting correlation coefficient is R2 = 0.997. Due to the random drift of Bragg wavelength, caused by the environment temperature fluctuations, the corresponding strain measurement precision is 0.05 με. The high-precision strain measurement by using the PSFBG with an ultra-narrow linewidth based on the frequency-stabilized laser is achieved, which will play an important role in the field of aerospace engineering, civil engineering, transportation engineering, energy engineering, mechanical and equipment manufacturing, etc.-
Keywords:
- strain measurement /
- π-phase-shifted fiber Bragg grating /
- frequency locking /
- photothermal effect /
- single-photon modulation
-
图 1 基于稳频激光的超窄线宽π相移光纤布拉格光栅应变测量实验装置图(虚线代表光信号, 实线代表电信号). Iso, 隔离器; Att, 衰减器; PSFBG, π相移光纤布拉格光栅; PZT, 压电换能器; SPD, 单光子探测器; TEC, 温控器; +, 加法器; LIA, 锁相放大器; FG, 信号发生器; HVA, 高压放大器
Fig. 1. Experimental setup for strain measurement by using π-phase-shifted fiber Bragg grating with an ultra-narrow linewidth based on frequency-stabilized laser (dashed lines for the light signal, solid lines for the electrical signal). Iso, isolator; Att, attenuator; PSFBG, π-phase-shifted fiber Bragg grating; PZT, piezoelectric transducer; SPD, single-photon detector; TEC, temperature controller; +, adder; LIA, lock-in amplifier; FG, function generator; HVA, high-voltage amplifier.
图 2 (a) π相移光纤布拉格光栅透射光谱; (b) 慢轴透射峰
Fig. 2. (a) The π-phase-shifted fiber Bragg grating transmission spectrum; (b) transmission peak for slow axis.
图 3 激光频率未锁定与锁定的测量结果, 插图为误差信号
Fig. 3. Measurement results when laser frequency is unlocked and locked, and inset is error signal.
图 4 布拉格波长随外部应力变化的测量结果
Fig. 4. Measurement results of Bragg wavelength variation with external strain.
-
[1] Sun Q Q, Zhang M Z, Zhao S S, Ji L T, Su J, Xu J, Yang B, Wu C 2025 Opt. Lasers Eng. 194 109147
Google Scholar
[2] Kok S P, Go Y I, Wang X, Wong M L D 2024 IEEE Sensors J. 24 29485
Google Scholar
[3] Abdulraheem M I, Xiong Y, Zhang W, Chen H, Zhang H, Hu J 2024 Int. J. Precis. Eng. Manuf. 25 1499
Google Scholar
[4] Xu S Y, Li X Z, Wang T Y, Wang X J, Liu H 2023 Opt. Eng. 62 010902
[5] Hu X Y, Xu Y, Zhang H X, Xie J H, Niu D Q, Zhao Z, Qu X 2023 IEEE Sensors J. 23 11374
Google Scholar
[6] Zhai H Z, Wu Q, Xiong K, Wang R 2019 IEEE Photon. Technol. Lett. 31 1335
Google Scholar
[7] Pashaie R, Vahedi M 2022 Opt. Quant. Electron. 54 85
Google Scholar
[8] Xiang R, Chen C X, Kong B, Hong Q S, Lu L 2022 Optics and Photonics J. 12 269
Google Scholar
[9] Liu T, Li Y W, Dai X Y, Gan W B, Wang X S, Dai S X 2023 J. Lightw. Technol. 41 5169
Google Scholar
[10] Cheng H, Wang L, Wang J 2023 Opt. Fiber Technol. 79 103363
Google Scholar
[11] Tian T, Zhou X, Wang S H, Luo Y, Li X G, He N H, Ma Y L, Liu W F, Shi R B, Ma G N 2022 Energies 15 5849
Google Scholar
[12] Zhang F, Buchfellner F, Hu W B, Ao W X, Bian Q, Roths J, Yang M H 2025 Photon. Sens. 15 250204
Google Scholar
[13] Daxini S, Aydin D, Giron A, Barnes J, Gu X J, Loock H P 2025 Opt. Express 33 6039
Google Scholar
[14] Danish Nadeem M, Kumar Raghuwanshi S, Kumar S 2022 IEEE Sensors J. 22 7463
[15] Ji L T, Li G, Zhang C, Su J, Wu C 2021 IEEE Sensors J. 21 27482
Google Scholar
[16] Srivastava D, Das B 2020 Sens. Actuators A Phys. 315 112215
Google Scholar
[17] Miao S J, Zhang W T, Song Y, Huang W Z 2020 Opt. Express 28 12699
Google Scholar
[18] Man W Q, Zhang C Y, Peng J, He Q P 2025 J. Optoelectron. Adv. Mater. 27 107
[19] Chow J H, Sheard B S, Mcclelland D E, Gray M 2005 Opt. Lett. 30 708
Google Scholar
[20] Painchaud Y, AubéM, Broch G, Picard M 2010 Proc. Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, OSA Technical Digest Paper BTuC3
[21] Ding M, Chen D J, Fang Z J, Wang D, Zhang X, Wei F, Yang F, Ying K, Cai H W 2016 Opt. Express 24 25370
Google Scholar
[22] 于波, 景明勇, 胡建勇, 张国峰, 肖连团, 贾锁堂 2016 激光与光电子学进展 53 080604
Google Scholar
Yu B, Jing M Y, Hu J Y, Zhang G F, Xiao L T, Jia S T 2016 Laser Optoelectron. Prog. 53 080604
Google Scholar
下载:
计量
- 文章访问数: 223
- PDF下载量: 6
- 被引次数: 0
