Tapered optical fiber addresses challenge posed by Brillouin scattering

澳门威尼斯人网上赌场澳门威尼斯人网上赌场人员实现了与长寿命声波的强光声相互作用.

When optical beams, consisting of photons, travel through fibers, they cause vibrations that generate acoustic waves, consisting of phonons. The phenomenon, called Brillouin scattering, 已经被澳门威尼斯人网上赌场人员利用光机械“耦合”声波和光波. This coupling allows information carried by photons to be transduced, or converted, to the phonons, which travel nearly a million times more slowly than light waves.

光声耦合使澳门威尼斯人网上赌场人员能够更容易地读取和处理转导信息. To date, however, 澳门威尼斯人网上赌场人员使用的许多布里渊散射技术依赖于使声波迅速消失的标准光纤几何形状, limiting the efficacy of the coupling.

Now, using an optical fiber with a micron-sized waist, University of Rochester 澳门威尼斯人网上赌场人员已经演示了如何耦合传播光波和长寿命声波, with strong optical-acoustic interactions.

“这是一个独特而理想的组合，以前从未实现过,” says Wendao Xu, a PhD candidate in the research group of William Renninger, assistant professor at Rochester’s Institute of Optics. Xu is the lead author of a paper in Optica describing the breakthrough.

这一突破使光脉冲携带的信息能够暂时存储在缓慢传播的声波中，足够长的时间让第二个光脉冲“读取”信息. The achievement could have applications for light storage, radio-frequency photonics filtering, and optical delay lines.

该澳门威尼斯人网上赌场在WOMBAT 2022光力学和布里渊散射研讨会上获得了最佳演讲奖 Max Planck Institute for the Science of Light, where it was presented by coauthor Arjun Iyer, also a PhD candidate in Renninger’s lab.

“Wendao, Arjun, 我们在东京大学的合作伙伴在展示这个新平台的前景方面做得很好，我们都很兴奋，因为我们开始专注于下一代设备和现实世界的应用,” Renninger says.

Brillouin scattering in optical fibers: overcoming challenges

“声波的振幅在传播过程中不断减小，”徐解释说. “Basically, 人们现在正在处理的所有高冲击布里渊散射都会产生强相互作用, but the acoustic waves are high in frequency, in the gigahertz range. 频率越高，电波在消失之前传播的时间就越短.”

徐的锥形光纤器件实现了强相互作用和更长的声学寿命. 它由去除包层(涂层)的多模玻璃纤维组成. 通过加热纤维的中心，同时施加机械张力拉伸纤维的两端, Xu and his collaborators produced a tightly confined, symmetrical “waist” in the fiber.

这种腰提供了理想的光机械重叠，产生迄今为止从纤维锥度观察到的最强布里渊耦合强度, 并可与任何系统的最大光机耦合强度相媲美,” the paper notes.

Moreover, 该装置产生的声子的寿命约为2微秒，足够长，光脉冲携带的信息可以暂时存储在这种缓慢传播的声波中，并保持相对较长的时间, before a second pulse of light reads the information.

A tapered optical fiber device

According to Iyer, Xu’s achievement is twofold. “One is the system, the tapered fiber device, 它支持一种人们以前没有太多关注的声波族,” he says. “The other is the process itself, 利用两种不同的光学空间模式之间的相互作用来得到我们想要的.”

这一过程——包括实现与长声子寿命强相互作用所涉及的物理学——可以立即加以调整和应用，以改进现有技术, he says. For example, detecting and filtering out unwanted radio frequencies in photonic filters, 或产生光纤传输延迟以补偿光纤系统中的延迟差异.

The tapered fiber system, on the other hand, while useful for research, is likely too fragile for real world applications outside the lab, Iyer says. “这些是微米大小的玻璃细丝，就挂在那里，”他说.

However, 澳门威尼斯人网上赌场人员已经在探索将该系统打包用于现实世界应用的方法, Iyer says.

Other collaborators include Lei Jin and Sze Y. 位于东京大学先进科学技术澳门威尼斯人网上赌场中心. 这项澳门威尼斯人网上赌场得到了澳门威尼斯人网上赌场和美国国家科学基金会的资助. 罗彻斯特大学集成纳米系统中心为锥形装置的扫描电子显微镜表征提供了专业知识和帮助.

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