Brillouin-based fiber-optic sensing has been regarded as a powerful distributed measurement tool for monitoring the conditions of modern large civil and geotechnical structures, since it provides continuous environmental information (e.g., temperature and strain) along the whole fiber used for sensing applications. In the past few decades, great research efforts were devoted to improve its performance in terms of measurement range, spatial resolution, measurement speed, sensitivity, and cost-effectiveness, of which the slope-assisted measurement scheme, achieved by exploiting the linear slope of the Brillouin gain spectrum (BGS), have paved the way for dynamic distributed fiber-optic sensing. In this article, slope-assisted Brillouin-based distributed fiber-optic sensing techniques demonstrated in the past few years will be reviewed, including the slope-assisted Brillouin optical time-domain analysis/reflectometry (SA-BOTDA/SA-BOTDR), the slope-assisted Brillouin dynamic grating (BDG) sensor, and the slope-assisted Brillouin optical correlation domain analysis/reflectometry (SA-BOCDA/SA-BOCDR). Avenues for future research and development of slope-assisted Brillouin-based fiber-optic sensors are also prospected.

Xinyu Fan

Bin Wang

Guangyao Yang

Zuyuan He

Slope-Assisted Brillouin-Based Distributed Fiber-Optic Sensing Techniques

Thermally drawn multimaterial fibers have experienced rapid development in the past two decades owing to the high scalability, uniformity, and material and structure compatibility of the thermal drawing technique. This article reviews various multimaterial fibers based on different functional structures and their applications in disparate fields. We start from the functional structures achieved in optical fibers developed in the early stage of thermally drawn fibers. Subsequently, we introduce both typical functional structures and unique structures created in multimaterial fibers for varying applications. Next, we present the early attempts in breaking the axial symmetric structures of thermally drawn fibers for extended functionalities. Additionally, we summarize the current progress on creating surface structures on thermally drawn fibers. Finally, we provide an outlook for this trending topic towards wearable devices and smart textiles.

Zhe Wang

Mengxiao Chen

Yu Zheng

Jing Zhang

Zhixun Wang

Jiao Yang

Qichong Zhang

Bing He

Miao Qi

Haozhe Zhang

Kaiwei Li

Lei Wei

Advanced Thermally Drawn Multimaterial Fibers: Structure-Enabled Functionalities

Recently, Rayleigh scattering-based distributed fiber sensors have been widely used for measurement of static and dynamic phenomena such as temperature change, dynamic strain, and sound waves. In this review paper, several sensing systems including traditional Rayleigh optical time domain reflectometry (OTDR), <svg xmlns="http://www.w3.org/2000/svg" id="M1" style="vertical-align:-0.04981995pt" height="8.3338pt" version="1.1" viewBox="-0.0498162 -8.28398 9.6623 8.3338" width="9.6623pt">


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</svg>-OTDR, and optical frequency domain reflectometry (OFDR) are introduced for their working principles and recent progress with different instrumentations for various applications. Beyond the sensing technology and instrumentation, we also discuss new types of fiber sensors, such as ultraweak fiber Bragg gratings and random fiber gratings for distributed sensing and their interrogators. Ultimately, the limitations of Rayleigh-based distributed sensing systems are discussed.

Xiaoyi Bao

Yuan Wang

Recent Advancements in Rayleigh Scattering-Based Distributed Fiber Sensors

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<p>The open access journal <em>Advanced Devices &amp; Instrumentation</em>, published in association with BIACD, is a forum to promote breakthroughs and application advances at all levels of electronics and photonics.</p>


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<p><em>Advanced Devices &amp; Instrumentation’s</em>&nbsp;editorial board is led by Wei Wang (China Aerospace Science and Technology Corporation) and&nbsp;Daping Chu (University of Cambridge) and is comprised of experts who have made significant and well recognized contributions to the field.</p>


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<p><em>Advanced Devices &amp; Instrumentation</em> is now accepting submissions for its first special issue: <a href="https://spj.sciencemag.org/adi-special-issues/metasurfaces/">Metasurface-Based Devices</a></p>
