/PRCWT/Guangzhou, April 24, 2023——Modern-day technologies like optical computing, integrated photonics, and digital holography require light signals to be manipulated in three dimensions. To achieve this, it is necessary to be able to shape and guide the flow of light according to its desired application. Given that light flow within a medium is governed by the refractive index, specific tailoring of the refractive index is needed to realize control of the light path within the medium.现代技术，如光学计算、集成光子学和 数字全息术需要在三维中操纵光信号。 要实现这一点，就必须能够塑造和引导光的流动 根据其期望的应用。假设介质中的光流动是 由折射率决定，折射率的具体定制是 实现介质内光路的控制所需要的。
To this end, scientists have developed what are called "aperiodic photonic volume elements" (APVEs), microscopic voxels with specific refractive indices located at predefined positions to direct the flow of light in a controlled manner. However, sculpting these elements requires a high degree of precision, and most light-shaping materials are limited to 2D configurations or end up degrading the output light beam profile.为此，科学家们开发了所谓的“非周期性光子 体积元素”（APVE），具有特定折射率的微观体素 其位于预定义的位置处以在受控的光传输路径中引导光的流动。 举止然而，雕刻这些元件需要高度的精确度， 并且大多数光成形材料限于2D配置或最终 从而降低输出光束轮廓。
In a recent study published in Advanced Photonics Nexus (APNexus), researchers led by Alexander Jesacher from the Medical University of Innsbruck in Austria proposed a simple approach to fabricating highly precise APVEs for a range of applications. The method uses a technique called "direct laser writing" for the 3D arrangement of voxels of specific refractive indices inside borosilicate glass.在最近发表在Advanced Photonics Nexus（APNexus）上的一项研究中 由因斯布鲁克医科大学的亚历山大·杰萨彻领导的研究人员 在奥地利提出了一种简单的方法来制造高精度APVE为 应用范围。该方法使用一种称为“直接激光写入”的技术 对于内部特定折射率的体素的3D布置 硼硅酸盐玻璃
In their study, the researchers designed an algorithm that stimulates the flow of light through a medium to determine the optimum placement of voxels for achieving the necessary precision. Based on this, they were able to generate between 154,000 and 308,000 voxels, each occupying a volume of approximately 1.75 µm × 7.5 µm × 10 µm, within just 20 minutes. Additionally, they used dynamic wavefront control to compensate for any spherical aberration (beam profile distortion) during the focusing of laser on the substrate. This ensured the consistency of each voxel profile at all depths within the medium.在他们的研究中，研究人员设计了一种算法，可以刺激 通过介质的光的流动，以确定体素的最佳放置 达到必要的精度。在此基础上，他们能够生成 在154，000和308，000个体素之间，每个体素占据大约10000个像素的体积。 1.75µm × 7.5 µm × 10 µm，仅需20分钟。此外，他们使用 动态波前控制以补偿任何球面像差（光束 轮廓变形）。这确保了 介质内所有深度处的每个体素轮廓的一致性。
The team developed three types of APVEs to demonstrate the applicability of the method: an intensity shaper for controlling the intensity distribution of the input beam, an RGB multiplexer that manipulated the transmission of the red-green-blue (RGB) spectra of the input beam, and a Hermite–Gaussian (HG) mode sorter to enhance data transfer speeds.该团队开发了三种类型的APVE，以证明 所述方法：强度整形器，用于控制 输入光束，RGB多路复用器操纵的传输 输入光束的红-绿-蓝（RGB）光谱，以及厄米-高斯（HG）模式 分类器，以提高数据传输速度。
The team used the intensity shaper to convert a Gaussian beam into a microscopic smiley-shaped light distribution, followed by the multiplexer to represent different parts of the smiley distribution in different colors, and finally the HG mode sorter to convert multiple Gaussian mode inputs delivered by the optical fibers into HG modes. In all cases, the devices were able to transmit the input signal without significant loss and achieved a record-high diffraction efficiency of up to 80 percent, setting a new benchmark for the standard of APVEs.该团队使用强度整形器将高斯光束转换为 显微笑脸形光分布，然后由多路复用器 用不同的颜色表示笑脸分布的不同部分，以及 最后，HG模式分类器转换由 将光纤转换成HG模式。在所有情况下，这些设备都能够 传输输入信号无明显损失，并实现了创纪录的高 衍射效率高达80%，为 APVE标准。
"The results reported in this paper greatly advance the field of ultrafast laser direct writing. The novel method could open doors to an ideal low-cost platform for a rapid prototyping of highly integrated 3D light shapers," says APNexus Editorial Board Member Paulina Segovia-Olvera of the Center for Scientific Research and Higher Education at Ensenada (CICESE). "The demonstration of a solid method for producing consistent, reproducible, and reliable APVEs not only adds to the current knowledge in the field but also enables new avenues in applied photonics," she adds.and the results show that the technology is more efficient.“ 激光直写这种新方法可以为理想的低成本 高度集成的3D光整形器的快速原型平台，”他说 APNexus编辑委员会成员保利纳Segovia-Olvera，来自 科学研究和高等教育在恩塞纳达（CICESE）。“The 生产一致的、可重现的和可重复的 可靠的APVE不仅增加了该领域的现有知识，而且 为应用光子学开辟了新的途径，”她补充说。
The method, in addition to its simplicity, low cost, and high precision, can probably also be extended to other substrates, including nonlinear materials. "The flexibility of our method could make it viable for designing a wide range of 3D devices for applications in information transport, optical computing, multimode fiber imaging, nonlinear photonics, and quantum optics," concludes Jesacher.该方法除了简单、低成本和高精度之外，还可以 可能也可以扩展到其他基板，包括非线性材料。 which can be used to design a wide range of 用于信息传输，光学计算， 多模光纤成像，非线性光子学和量子光学，”总结道 杰萨彻
