AI 中文总结
本研究采用低温光纤探针台，探究薄膜铌酸锂（TFLN）器件从室温到5 K低温下的特性，明确温度降低带来的谐振、半波电压及相位匹配偏移等变化，为相关量子器件开发提供支撑。
AI 中文摘要
工作在低温下的光子集成电路是量子转换、集成单光子发射体与探测器、深空通信及传感等众多量子技术的必要组成部分。薄膜铌酸锂（TFLN）是一种新兴平台，具备低损耗、快速电光可重构性、非线性量子光源，以及承载量子发射体和单光子探测器的能力，是全集成量子光子学的有力候选。为将TFLN与超导单光子探测器、微波-光转换器、固态量子发射体等需低温运行的技术对接，研究其从室温到低温的光学与电学特性十分重要。本研究采用可实现低至5 K全温度控制的低温光纤探针台，对TFLN中的跑道谐振器、马赫-曾德尔调制器、周期极化波导等线性与非线性光子器件展开研究，量化得出：随样品温度降低，谐振峰发生偏移，电光调制器半波电压提升22%，0型相位匹配发生18 nm蓝移，II型相位匹配发生64 nm红移。本对低温环境下非线性过程的研究，将助力开发用于平台间量子信息处理、安全通信及增强传感的新型器件。
英文摘要
Photonic integrated circuits operating at cryogenic temperatures are necessary for many quantum technologies such as quantum transduction, integrated single-photon emitters and detectors, as well as deep-space communication and sensing devices. Thin-film lithium niobate (TFLN) is an emerging platform that is a strong candidate for fully integrated quantum photonics, offering low loss, fast electro-optic reconfigurability, nonlinear quantum light sources, and the ability to host quantum emitters and single-photon detectors. To interface TFLN with technologies that require cryogenic operation, like superconducting single-photon detectors, microwave-to-optical transducers, and solid-state quantum emitters, it is important to study its optical and electrical properties from room temperature down to cryogenic temperatures. Here, we investigate linear and nonlinear photonic devices, including racetrack resonators, Mach-Zehnder modulators and periodically poled waveguides in TFLN using a cryogenic fiber probe station with full temperature control down to 5 K. We quantify a shift in resonances, a 22% increase in electro-optic modulator half-wave voltage, a blue shift of 18 nm for Type-0 phase-matching as well as a red shift of 64 nm for Type-II phase-matching as the sample temperature decreases. Our study of nonlinear processes in a cryogenic environment will contribute towards developing novel devices for inter-platform quantum information processing, secure communication, and enhanced sensing.
