PFI:AIR - TT: BaTiO3 Photonic Crystal Electro-optic Devices for 50 GHz Applications

该PFI加速创新技术项目的重点是开发用于超高带宽光学系统的光子晶体（PhC）电光调制器原型。这一点很重要，因为在未来，由于数据中心、住宅系统、移动智能手机和智能网络通信的连接要求，通信和网络系统将需要具有超高传输速率的光学子系统。光调制器是光学系统的关键部件，目前是限制数据传输速率的器件。该项目的重点是开发一种基于钛酸钡（BaTiO3）铁电氧化物薄膜的可工作的封装原型光学调制器，带宽为50 GHz，比目前基于铌酸锂（LiNbO3）的先进技术高25%。铌酸锂（LiNbO3）由于其较高的电光（EO）系数，已被确立为光学调制器的首选电光材料。然而，它在微波频率下具有很高的介电常数，这限制了传统调制器的带宽为40千兆赫（GHz）或更少。基于硅、磷化铟和聚合物材料的方法已经被广泛研究，以解决这一重大挑战，尽管取得了进展，但在速度和功率方面仍然存在许多重大挑战。该项目采用了另一种方法，使用实验证明电光（EO）系数比LiNbO3高出一个数量级的BaTiO3铁电氧化物薄膜。本课题将开发具有光子晶体波导结构的封装EO调制器。器件将使用气相外延沉积、传统光刻和聚焦离子束铣削制造。与其他光调制器应用平台相比，BaTiO3薄膜平台具有许多竞争优势，例如：(1)大的EO系数，比主导光调制器市场的LiNbO3器件高十倍；(2)驱动电压低，功耗低；(3)显示了超过50 GHz的超高带宽，潜在达到亚太赫兹区域；(4)与硅电子集成的潜力，可实现超低成本的超高紧凑光电元件。通过使用具有非线性光子晶体的BaTiO3薄膜平台，与传统器件相比，有望在带宽，工作电压和尺寸方面取得显着改善。将演示一个工作封装的原型50 GHz带宽调制器，长1毫米。该项目将包括培训光子晶体设计方面的研究生和博士后学者，并通过原型的开发和演示提供技术转移的经验。

This PFI Accelerating Innovation Technology Project focuses on the development of a prototype Photonic crystal (PhC) electro-optic modulator for ultra-high bandwidth optical systems. This is important because in the future, communication and cyber systems will require optical subsystems with ultra-high transmission rates due to the connectivity requirements of data centers, residential systems, mobile smartphones, and smart network communications. The optical modulator is a key piece of optical systems and at present is the component that limits the data transmission rates. This project focuses on developing a working, packaged prototype optical modulator based on barium titanate (BaTiO3) ferroelectric oxide thin films with a bandwidth of 50 GHz, which is 25% higher than the current state of the art technology based on Lithium niobate (LiNbO3). Lithium niobate (LiNbO3) has been established as the electro-optic material of choice for optical modulators due to its relatively high electro-optic (EO) coefficient. However, it has a high dielectric constant at microwave frequencies, which limits the bandwidth of conventional modulators to 40 gigahertz (GHz) or less. Approaches based on silicon, indium phosphide and polymeric materials have been widely investigated to solve this major challenge and although progress has been made, a number of significant challenges in speed and power required remain. This project takes an alternative approach by using BaTiO3 ferroelectric oxide thin films with experimentally demonstrated electro-optic (EO) coefficients more than an order of magnitude higher than that of LiNbO3. In this project, packaged EO modulators with photonic crystal waveguide structure will be developed. Devices will be fabricated using vapor phase epitaxial deposition, and both conventional photolithography and focused ion beam milling. The BaTiO3 thin film platform has numerous competitive advantages over other platforms for optical modulator applications such as (1) Large EO coefficient, ten times higher compared to those of LiNbO3 devices dominating optical modulator markets; (2) Low driving voltage thus low power consumption; (3) Ultrahigh bandwidth higher than 50 GHz demonstrated with potential reaching sub-THz regime; (4) potential for integration with Si electronics leading to ultrahigh compact electro-optical components at low cost. By using a BaTiO3 thin film platform with non-linear photonic crystals, significant improvements in bandwidth, operating voltage, and size are expected compared to conventional devices. A working packaged, prototype 50 GHz bandwidth modulator, 1mm long, will be demonstrated. The project will involve training of graduate students and postdoctoral scholars in photonic crystal design as well as offering experiences with technology transfer through the development and demonstration of the prototype.