EVacuAted OptiCal Fibres for Ultimate UV-to-Infrared Light TransMission (VACUUM)

用于终极紫外到红外光传输（真空）的真空光纤

• 批准号: EP/W037440/1
• 负责人: Radan Slavik
• 金额: $ 109.6万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW037440%2F1
• 关键词: EVacuAted; OptiCal; Fibres; Ultimate; UV

Over the last four decades, optical fibres have revolutionised telecommunications and enabled Internet as we know it today. Sensing is another area where optical fibres are used, for example for monitoring engineering structures (e.g., strain and vibration along bridges, tunnels, etc.), or to deliver light for advanced instruments such as next-generation microscopes that can see material/tissue properties that are invisible with traditional instruments. Optical fibres are also leading a revolution in manufacturing by generating and delivering intense laser light capable of welding and cutting.However, conventional fibres, where light propagates through glass, cannot cope with such high powers due to the onset of nonlinear effects and material damage caused by the high light intensities. Glass absorption also limits the exploitation of fibre technologies in the visible and near/mid-infrared. These shortcomings are being addressed by the next generation of optical fibres, so-called hollow-core fibres that guide light through a central hole, thus avoiding significant light-glass interaction. Light in these fibres is guided thanks to a specially engineered glass microstructure built around a central hole. Recently, the design and manufacturing of this microstructure has been improved significantly and hollow-core fibres are now emerging with properties that surpass those of traditional fibres in almost every regard. In these novel fibres, light propagates through the core; in most cases the core contains air which enters the fibre during fabrication or onward handling. Although light interacts with air significantly less than with glass, this interaction nevertheless still imposes appreciable limitations. One example is absorption at wavelengths such as 1300 nm (due to water vapour) or in the mid-infrared (absorption of atmospheric gases). Another example relates to the transmission of high-power pulses (e.g., as needed for laser based welding) where nonlinear optical interactions with the air result in significant beam distortions. The ultimate solution would be to evacuate the fibre core, thereby eliminating the air-light interaction. Preliminary calculations show that evacuating a long length of hollow-core fibre (kilometres) would take impractically long (years) due to the small core diameter (typically ~0.03 mm). Techniques to characterize the gas pressure or content along the fibre length have also not been developed yet. Without such measurements, it is difficult to monitor the evacuation process, or to validate models that describe the evacuation process. This project is dedicated to investigating, theoretically and experimentally, techniques to accurately characterize the (residual) air pressure along a length of hollow-core fibre. Subsequently, we will research several solutions to reliably evacuate them over long lengths and to seal them while enabling low loss coupling of light in and out. Finally, we will demonstrate how these improved hollow-core fibres will enable next-generation applications, targeting three selected areas:1) telecommunications, where evacuation will enable communication over a large wavelength range, increasing several times how much data can be transmitted over a given time. 2) high-power laser pulses for welding/drilling/mining, but also bio-medical imaging, where we expect up to 100-1000 times larger powers to be deliverable through the evacuated hollow-core fibres as compared to air-filled ones and up to one million times more than with today's glass-core fibres. 3) transmission of mid-infrared light ("molecular fingerprint region") and demonstration of applications in remote hydrocarbon analysis, of interest, e.g., in oil wells. Evacuated hollow-core fibres will offer superior performance to any other fibre technology, ranging from guiding in the UV all the way to mid-infrared, opening new opportunities in science, technology, and applications.

在过去的四十年中，光纤彻底改变了电信，并启用了我们今天所知道的互联网。传感是使用光纤的另一个领域，例如用于监视工程结构（例如，沿桥梁，隧道等）的工程结构（例如，应变和振动），或为高级仪器（例如下一代显微镜）提供光线，这些仪器可以看到传统仪器不可见的材料/组织性能。光纤还通过产生和传递能够焊接和切割的强烈激光灯来引发制造业的一场革命。但是，由于传统纤维在玻璃中传播的传统纤维无法应付由于高光强度引起的非线性效应和材料损害而导致的高功率。玻璃吸收还限制了可见的和接近/中红外的纤维技术的开发。这些缺点是通过下一代光纤，即所谓的空心核纤维来解决的，这些纤维引导光线穿过中央孔，从而避免了明显的浅玻璃相互作用。这些纤维中的光得益于围绕中央孔建造的特殊设计的玻璃微观结构。最近，该微观结构的设计和制造已得到显着改进，而空心核纤维现在已经出现了几乎所有方面都超过传统纤维的属性。在这些新颖的纤维中，光通过核心传播。在大多数情况下，核心包含在制造或继续处理过程中进入纤维的空气。尽管光与玻璃的相互作用明显少于玻璃，但这种相互作用仍然会引起明显的局限性。一个例子是在1300 nm（由于水蒸气）或中红外（大气气体的吸收）等波长处的吸收。另一个示例涉及高功率脉冲的传播（例如，基于激光的焊接需要），其中非线性光学相互作用与空气导致显着的光束失真。最终解决方案是撤离纤维芯，从而消除空气相互作用。初步计算表明，由于核心直径较小（通常〜0.03 mm），撤离长长的空心纤维（公里）将需要不切实际（年）。尚未开发出表征沿纤维长度的气压或含量的技术。没有这样的测量，很难监视疏散过程或验证描述疏散过程的模型。该项目致力于在理论上和实验上进行研究，以准确表征沿空心核纤维的（残留）气压。随后，我们将研究多种解决方案，以可靠地撤离它们，并密封它们，同时使光偶联下来降低损失耦合。最后，我们将展示这些改进的空心核纤维将如何实现下一代应用，以三个选定的领域为目标：1）电信，疏散将使在较大的波长范围内进行通信，并增加了几倍在给定时间内传输多少数据。 2）用于焊接/钻孔/采矿的高功率激光脉冲，但也是生物医学成像，与当今的玻璃核纤维相比，通过撤离空心核心纤维的撤离空心芯纤维相比，通过疏散的空心核纤维可传递高达100-1000倍的功率。 3）中红外光（“分子指纹区域”）和在远程烃分析中的应用，例如在油井中的应用。疏散的空心核纤维将为任何其他纤维技术提供卓越的性能，从一路引导到中志，开放科学，技术和应用方面的新机会。

项目成果

Support-Free Thermally Insensitive Hollow Core Fiber Coil

• DOI: 10.1109/jlt.2023.3241255
• 发表时间: 2023-05
• 期刊: Journal of Lightwave Technology
• 影响因子: 4.7
• 作者: Xuhao Wei;A. Taranta;Bo Shi;Meng Ding;Zitong Feng;D. Richardson;F. Poletti;R. Slavík

Direct and low-loss connection between a hollow-core optical fiber and a dispersion compensating fiber for dispersion-free delivery of short optical pulses in hollow-core fiber

空心光纤和色散补偿光纤之间的直接低损耗连接，用于在空心光纤中无色散传输短光脉冲

• DOI: 10.1117/12.2648720
• 发表时间: 2023
• 作者: Zhong A

Interconnectivity between effectively single-moded antiresonant hollow core fibres and conventional single-mode fibres

• DOI: 10.1016/j.yofte.2023.103541
• 发表时间: 2023-12
• 期刊: Optical Fiber Technology
• 影响因子: 2.7
• 作者: Radan Slavík;M. Komanec;E. N. Numkam Fokoua

All-fiber hollow-core fiber gas cell

• DOI: 10.1016/j.yofte.2023.103513
• 发表时间: 2023-12
• 期刊: Optical Fiber Technology
• 影响因子: 2.7
• 作者: D. Suslov;M. Komanec;T. Kelly;Ailing Zhong;Stanislav Zvánovec;Francesco Poletti;N. Wheeler;Radan Slavík

Distributed Characterization of Low-loss Hollow Core Fibers using EDFA-assisted Low-cost OTDR instrument

使用 EDFA 辅助的低成本 OTDR 仪器对低损耗空心光纤进行分布式表征

• DOI: 10.23919/ofc49934.2023.10117143
• 发表时间: 2023
• 作者: Wei X