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

这项PFI加速创新技术项目专注于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纤子系统。光调制器是光学系统中的关键部件，目前是限制数据传输速率的元器件。该项目致力于开发一种工作的、封装的基于钛酸钡铁电氧化物薄膜的光调制器原型，带宽为50 GHz，比目前基于铌酸锂(LiNbO_3)的技术水平高25%。由于其较高的电光系数(EO)，LiNbO_3已被确定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，这将传统调制器的带宽限制在40千兆赫(GHz)或更低。基于硅、磷化铟和聚合物材料的方法已被广泛研究以解决这一重大挑战，尽管已取得进展，但在速度和所需功率方面仍存在许多重大挑战。该项目采用了另一种方法，使用BaTiO3铁电氧化物薄膜，实验证明其电光系数比LiNbO3高一个数量级以上。在本项目中，将开发具有光子晶体波导结构的封装电光调制器。器件的制造将使用气相外延沉积，以及传统的光刻和聚焦离子束球磨。在光调制器应用方面，BaTiO3薄膜平台相对于其他平台具有众多竞争优势，如：(1)大的电光系数，比那些主导光调制器市场的LiNbO_3器件高出10倍；(2)低驱动电压，因此低功耗；(3)高于50 GHz的超高带宽显示出潜在的亚太赫兹效应；(4)可与硅电子器件集成，以低成本生产超高紧凑型电光元件。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有显著改善。将演示一个工作封装的、50 GHz带宽调制器的原型，长度为1 mm。该项目将对研究生和博士后学者进行光子晶体设计方面的培训，并通过原型的开发和演示提供技术转让的经验。

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.