GOALI: OP: Incongruent Growth of Single Crystal 3D Architecture for New Optical Functionalities in Glass

非技术描述：光子集成电路（PICs）是微电子电路的光学模拟，是通信、传感、信息、显示和其他技术下一个重大进步的关键。与离散系统相比，它们具有几个优势，包括更小的尺寸，更低的功耗，通过简化组件耦合和封装工艺获得更好的性能和可靠性，以及通过批量制造降低成本。目前用于制造PICs的方法适用于平面几何形状，而实现高密度器件元件需要制造3D系统，这对于光学计算，光通信和新型高密度光存储器尤为重要。实现这一目标的一个主要障碍是制造和集成透明、多功能微光学元件的困难，这些元件必须是低对称的晶体，而不是固有被动的玻璃。由里海大学的研究人员领导的一个跨国团队最近展示了使用飞秒（fs）激光制造3D玻璃单晶结构（SCAG）的原理验证。本研究将此方法进一步扩展，以具体实现康宁公司最近引入的“主状态传输”概念。它有望将光纤的传输带宽提高一个数量级，从而促进光通信的下一个突破。与此同时，该项目通过与康宁公司的合作，培训两名研究生进行应用驱动型研究，吸引一些本科生，并向K-12学生介绍激光制造新结构和器件的新兴领域。技术细节：激光辐射的非线性吸收允许加热玻璃内部深处，在其他发射光束的焦点处。这一特点和光束的控制平移已经被利用在一种可行的方法中，在一致结晶的硼锗酸镧模型组成中制造铁电SCAG。然而，由于两相的成分不同，玻璃到晶体的转变变得越来越复杂。因此，里海大学和康宁公司之间的GOALI合作重点是在不断变化的成分中对激光诱导晶体生长过程的基本理解，并应用这些知识来制造形状和尺寸适合原型器件的SCAG。通过团队之间的持续反馈和互动，正在开发制造工艺参数，SCAG结构和光学性能之间的相关性。这些结果有助于开发一种预测模型，该模型将为在适合于设备的复杂组合物中制造低光学损耗scag提供指导。

NON-TECHNICAL DESCRIPTION: Photonic integrated circuits (PICs), the optical analog of microelectronic circuits, are key to the next major advancement in communication, sensing, information, display, and other technologies. They offer several advantages compared to discrete systems including smaller size, lower power consumption, better performance and reliability through simplification of component coupling and packaging processes, and lower cost through batch fabrication. The methods currently employed for fabricating PICs are suitable for planar geometries, whereas achieving a high density of device elements requires fabrication of 3D systems that are particularly important for optical computing, optical communication and new forms of high density optical memory. A major hurdle toward this goal is the difficulty of fabrication and integration of transparent, multifunctional micro-optical elements, which must be crystals of low symmetry rather than glass that is inherently passive. A multinational team led by researchers at Lehigh University recently demonstrated the proof-of-principle for fabricating 3D single crystal architecture in glass (SCAG) using a femtosecond (fs) laser. The present research is extending this method further for specifically realizing the concept of "principal state transmission" recently introduced by Corning, Inc. It promises to increase the transmission bandwidth of an optical fiber by an order of magnitude, thereby facilitating the next breakthrough in optical communication. In parallel, the project is training two graduate students in application-driven research through collaboration with Corning, Inc., engaging a few undergraduate students and introducing K-12 students to the emerging field of laser fabrication of new structures and devices. TECHNICAL DETAILS: Nonlinear absorption of fs laser radiation allows heating a glass deep inside, at the focal point of the otherwise transmitting beam. This feature and controlled translation of the beam have been exploited in a viable method for fabricating ferroelectric SCAG in a congruently crystallizing lanthanum borogermanate model composition. However, the glass to crystal transformation becomes increasingly complex for compositions of practical interest, where the two phases have different compositions. Therefore, this GOALI collaboration between Lehigh University and Corning, Inc. is focusing on the fundamental understanding of fs laser-induced crystal growth process in continuously evolving composition, and applying this knowledge to fabricate SCAG of shape and size suitable for prototypic devices. Through continuous feedback and interactions between the teams, a correlation is being developed between the fabrication process parameters, structure of SCAG and optical performance. These results are helping to develop a predictive model that will provide guidelines for making lower optical loss SCAGs in complex compositions suitable for use in devices.