Creating dynamic poling of ferroelectric thin films for chip-scale reconfigurable optical systems

集成光子学概念是将薄膜技术应用于光学电路和器件，以实现高效，高性能和经济的光学系统。 人们可以将该领域视为集成电路的微电子学的光学等效物。 对集成光子学的兴趣是由对微型、便携式和高效的光通信、计算和感测平台的需求驱动的，这些平台不受大规模块体光学器件、分立元件和长距离光纤的限制。 应用包括产生不同颜色的光用于精密测量，控制短光脉冲用于高速信号处理，以及修改光颜色用于低噪声安全通信。 为了在薄膜中产生功能性光学器件，需要千伏范围内的电压用于被称为极化的过程。 因此，一旦通过外部高压电源制造，器件就是静态的。 该研究计划旨在将所需电压降低到仅几伏。 由于低电压要求，静态器件可以变为动态器件。 光学系统曾经被认为是固定的和不灵活的，现在变得可重新配置和可编程。 动态功能使得能够实现利用光的特性来克服电子所施加的物理限制的系统，从而影响信息技术、电信、医疗保健、生命科学和国防。 综合教育计划回应了将科学和工程与公共利益问题联系起来的挑战，通过开发经典和现代光学研讨会系列，为集成光学课程创建新的课堂模块，产生综合研究思维，并让研究生和本科生，代表性不足的群体和少数民族参与研究计划。建模、制造和测试，首次为芯片上的可重构光学系统创建铁电薄膜的动态极化。 目标是在具有光学透明的极化电极和低矫顽场的氧化镁掺杂的锂的晶片级薄膜中创建微尺度平面光波导，允许片上极化和自发极化波形的编程。 的设计和建模方法是基于数值解的非线性耦合振幅方程的基础上麦克斯韦方程。 该芯片将在俄亥俄州州立大学使用纳米级制造技术制造。 一系列具有可调中心频率和可调带宽的非线性光学现象将被演示。 新的宽带和紧凑的光学系统架构涉及光子学与集成电路中的电子学的融合。 该研究解决了硅中二阶极化率的缺乏，这是实现芯片级非线性光学的主要障碍。 该计划利用氧化镁掺杂的锂离子酸盐的亚微米薄膜的低矫顽场、具有微米尺度模场直径的带负载光波导、透明光学电极和片上加热器，以将极化所需的电压降低到小于5伏。 当直接在芯片上开发铁电畴的动态极化能力时，新的视野立即变得明显。 极化周期不再是静态的，而是可调的，并且极化电极现在可以被认为是可编程的。 极化周期的调节导致相位匹配频率的动态变化。 将极化编程为线性啁啾产生相位匹配带宽的动态控制。 这些概念提供了一种新的攻击方法，以实现动态可调的非线性光学系统在芯片上。这个奖项反映了NSF的法定使命，并已被认为是值得支持的评估使用基金会的智力价值和更广泛的影响审查标准。

The integrated photonics concept is the application of thin-film technology to optical circuits and devices for the purpose of achieving efficient, high-performance, and economical optical systems. One can view the field as the optical equivalent of microelectronics for integrated circuits. The interest in integrated photonics is driven by the need for miniature, portable, and efficient optical communications, computing, and sensing platforms that are not limited by large scale bulk optics, discrete components, and long distance optical fiber. Applications include the generation of light of different colors for precision measurements, the control of short optical pulses for high speed signal processing, and the modification of light color for low noise secure communications. To create functional optical devices in thin films, voltages in the kilovolt range are required for a process referred to as poling. Consequently, devices are static once fabricated by an external high voltage power supply. The research program aims to reduce the required voltage to only a few volts. Due to the low voltage requirements, static devices can become dynamic. Optical systems once thought of as fixed and inflexible become reconfigurable and programmable. Dynamic functionalities enable the realization of systems that utilize the properties of light to overcome the physical limitations imposed by electrons, impacting information technology, telecommunications, health care, the life sciences, and national defense. The integrated educational plan responds to the challenge of linking science and engineering to problems of public interest by developing a classical and modern optics seminar series, creating new classroom modules for integrated optics curriculum that engenders integrative research thinking, and involving graduate and undergraduate students, underrepresented groups, and minorities in the research program.A comprehensive research program is proposed involving theory, design, modeling, fabrication, and test to create dynamic poling of ferroelectric thin films for reconfigurable optical systems on a chip for the first time. The objectives are to create microscale planar optical waveguides in wafer scale thin films of magnesium oxide doped lithium niobate with optically transparent poling electrodes and low coercive field, allowing for on-chip poling and programming of the spontaneous polarization waveform. The design and modeling approach is based on numerical solutions to nonlinear coupled amplitude equations based on Maxwell's equations. The chip will be fabricated at Ohio State University using nanoscale fabrication techniques. A host of nonlinear optical phenomena with tunable center frequency and tunable bandwidth will be demonstrated. New broadband and compact optical system architectures involving the convergence of photonics with electronics in integrated circuits are envisioned. The research addresses the lack of second order susceptibility in silicon which is a major obstacle to achieving chip-scale nonlinear optics. The program exploits the low coercive field of sub-micrometer thin films of magnesium oxide doped lithium niobate, strip loaded optical waveguides with micrometer scale mode field diameter, transparent optical electrodes, and on-chip heaters to reduce the voltage required for poling to less than five volts. New horizons immediately become apparent when exploiting the capability of dynamic poling of the ferroelectric domains directly on-chip. Instead of being static, the poling period becomes tunable and poling electrodes can now be considered as programmable. Tuning the poling period results in the dynamic variation of the phase matching frequency. Programming the poling into a linear chirp produces dynamic control of the phase matching bandwidth. These concepts provide a new method of attack to achieve dynamically tunable nonlinear optical systems on a chip.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.