摘要
本文提出了一种基于分散红1/聚甲基丙烯酸甲酯聚合物(DR1/PMMA)与微纳锥形双模光纤(TTMF)结构的全光纤电场传感器,相比于传统的电场传感器,采用全光纤的结构最大程度减少了杂散电磁场对外界电磁场测量的电磁干扰问题。其中,经电极化处理之后的有机电光聚合物薄膜,电光系数达到了3.68 pm/V,并且有机电光聚合物薄膜质地柔软,可以更好地与高性能的光纤器件结合。实验证明,可以利用有机电光聚合物实现光纤器件的二阶非线性光学功能。本文使用锥形双模光纤作为基模与高阶模的模态干涉仪,经测试,在折射率为1.55~1.56时,器件的折射率灵敏度达到了8154.76 nm/RIU(灵敏度单位),在外加电场增大时,器件传输的干涉光谱会发生蓝移,在电场下具有相对较高的0.86 dB/V的灵敏度。
Objective With the rapid advancement of science and technology,the demand for precise electric field measurements is increasing across fields such as electric power,communication,industrial automation,and biomedicine.In real-world applications, electric field sensors often face complex and variable environmental conditions, including temperaturefluctuations and electromagnetic interference. Traditional electric field sensors frequently struggle to meet high-precisionmeasurements, but sensors based on micro-nano tapered two-mode fibers (TTMFs) combined with a disperse red1/polymethyl methacrylate polymer (DR1/PMMA) offer a promising solution for achieving high-precision measurements.In this paper, we aim to develop and validate a novel all-fiber electric field sensor, leveraging the combination of TTMF’ssensitivity and the exceptional electro-optic properties of the DR1/PMMA. The primary objective of this research is todesign an electric field sensor with high sensitivity, fast response, low temperature sensitivity, and excellent stability. TheTTMF’s dual-mode interference effect, paired with its unique geometry, provides high sensitivity. The all-fiber structuresimplifies the sensor fabrication process and enables seamless integration with other fiber optic devices, significantlyfacilitating the construction of complex fiber-optic sensing networks while reducing system integration challenges and costs.When combined with DR1/PMMA, the sensor exhibits significant output signal changes even with minor variations in theelectric field, making it highly suitable for high-precision measurement scenarios. In addition, DR1/PMMA’s picosecondlevelresponse speed allows the sensor to rapidly detect dynamic electric field changes, providing robust technical supportfor real-time monitoring and applications with high real-time demands. Unlike traditional liquid crystal (LC)-based electricfield sensors, DR1/PMMA-based sensors are largely insensitive to temperature changes, which enhances their stabilityand reliability in diverse environmental conditions while minimizing measurement errors caused by ambient temperaturefluctuations.Methods For the material selection, we choose DR1/PMMA film as the electro-optic material due to its excellentelectro-optic effect, allowing its refractive index to vary with the applied voltage. Tapered optical fibers are chosen as thesensing elements due to their low loss, strong evanescent field, miniaturized size, and high sensitivity, making them idealfor constructing highly sensitive sensors. We apply electropolarization to the DR1/PMMA film to enhance its electro-opticcoefficient, a critical factor for achieving high electric field sensitivity. The tapered waist region of the TTMF is thenintegrated onto the surface of the electropolarized DR1/PMMA film, ensuring close contact between the fiber and the filmto maximize light-polymer interaction. In the tapered region of the TTMF, modal interference occurs between higher-ordermodes and the fundamental mode. Since the refractive index of the DR1/PMMA film changes with applied voltage, thiscauses a modulation of the transmitted light within the fiber, leading to a shift in the interference pattern or a change in lightintensity at a specific wavelength. To evaluate the sensor’s performance, we construct an experimental setup, integratingthe TTMF with the electropolarized DR1/PMMA film, and apply different voltages to observe the optical fieldmodulation effect. Simulation software is also used to model the sensor structure, verifying its working principles andperformance characteristics.Results and Discussions In this paper, we propose several key innovations. Firstly, the all-fiber structure designsignificantly reduces the interference from external electromagnetic coupling, allowing the sensor to maintain high precisionin complex electromagnetic environments and enhancing system stability and reliability. Secondly, the compact size of thedevice facilitates portability and deployment, enabling its use across a broader range of scenarios. The sensor’s opticalsignal modulation capability ensures high-speed signal transmission, shortening response time and enhancingelectromagnetic interference resistance. This makes it ideal for capturing electric field changes in environments with strongelectromagnetic fields. The sensor’s design exhibits excellent sensitivity and low signal distortion, crucial for high-preciseapplications such as monitoring electric fields in medical equipment or troubleshooting precision electronics. Structurally,the sensor is straightforward and easy to fabricate, reducing production costs and simplifying maintenance. Notably, theuse of DR1/PMMA, an organic electro-optic polymer, provides both ease of processing and molding, along with a highelectro-optic coefficient, forming a solid material foundation for high-sensitivity sensing. In addition, the innovative use ofTTMF as the modal interferometer substrate fully exploits the characteristics of tapered fibers, such as low loss, strongevanescent fields, and compact size. The design also strengthens the fiber’s mechanical resilience, reducing the risk ofdamage from external forces and further enhancing the durability and longevity of the sensor.Conclusions In this paper, we propose an innovative all-fiber electric field sensor architecture by integrating a highlysensitive TTMF with a DR1/PMMA electro-optic film. The core of the design is the DR1/PMMA film, which boasts aremarkable electro-optic coefficient of 3.68 pm/V, providing a strong foundation for the sensor’s performance. By utilizingthe high refractive index sensitivity (8154.76 nm/RIU) of the DR1/PMMA film, we have achieved a sensor design capableof rapid and highly sensitive electric field detection. Experimental validation demonstrates that the sensor’s impressiveelectric field sensitivity of 0.86 dB/V, along with a 3 dB bandwidth of 1.4 kHz, enabling broad signal transmissioncoverage. In addition, the sensor effectively limits harmonic distortion to less than 2.5% in the AC electric field range of 1to 5 kHz, ensuring high-fidelity signal transmission. Looking ahead, applying the proposed structure and fabricationmethods to other polymers with high electro-optic coefficients opens up new possibilities for creating high-performancefiber-optic electric field sensors.
作者
宋奇震
刘锋
杨彦博
张文香
吴梓烨
李卓奇
李志斌
樊鹏鹏
唐洁媛
朱文国
郑华丹
钟永春
陈哲
余健辉
Song Qizhen;Liu Feng;Yang Yanbo;Zhang Wenxiang;Wu Ziye;Li Zhuoqi;Li Zhibin;Fan Pengpeng;Tang Jieyuan;Zhu Wenguo;Zheng Huadan;Zhong Yongchun;Chen Zhe;Yu Jianhui(Department of Optoelectronic Engineering,College of Physics and Optoelectronic Engineering,Jinan University,Guangzhou 510632,Guangdong,China;Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes,Jinan University,Guangzhou 510632,Guangdong,China)
出处
《光学学报》
CSCD
北大核心
2024年第22期27-38,共12页
Acta Optica Sinica
基金
国家重点研发计划(2021YFB2800801)
国家自然科学基金(12174155)
中央高校基本科研业务费专项资金(11624108)。
