基于双光子聚合的片上光学互连(特邀)  

On-chip Optical Interconnection Based on Two-photon Polymerization(Invited)

作　　者：赵曜 林琳涵 孙洪波[1] ZHAO Yao;LIN Linhan;SUN Hongbo(State Key Laboratory of Precision Measurement Technology and Instruments,Department of Precision Instrument,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学精密仪器系,精密测试技术及仪器国家重点实验室,北京100084

出　　处：《光子学报》2022年第8期213-223,共11页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.62075111,61960206003);国家重点研发计划(No.2020YFA0715000);佛山-清华产学研合作协同创新专项资金(No.2021THFS0206);精密测试技术及仪器国家重点实验室自主课题。

摘　　要：集成光子芯片是将激光光源、低损耗波导、调制器、探测器等多类光电器件结合在一起,实现功能化集成,在高速光通讯、量子信息处理、光学传感等领域有具有重要的应用。然而由于不同的光电器件基于不同材料体系,实现多材料体系的光电器件集成极其困难。传统的异质集成和单片集成方法难以同时解决定位精度不足、低拓展性、高损耗、低带宽等一系列问题。基于飞秒激光的双光子聚合技术具有高精度和高穿透的优势,可以实现多材料体系的片上微纳光学元件增材制造,具有极高的加工自由度。本文对片上光学元件的激光增材制造这一领域进行综述,探讨了光子引线键合和微空间光路元件两种技术路径,总结了现有技术的发展现状,并对未来的发展前景进行了展望。Integrated photonic chip is a combination of optoelectronic devices such as laser light sources,low-loss waveguides,modulators,detectors,etc.,to achieving specific functionality. Integrated photonic chip provides important applications in high-speed optical communication, quantum information processing,optical sensing,optical manipulation,and so on. However,the fabrication of optoelectronic devices relies on different materials,it is extremely difficult to achieve photonic integration. The traditional heterogeneous integration and monolithic integration methods cannot simultaneously solve the problems such as low positioning accuracy,low scalability,high loss,and low bandwidth. Inspired by the direct wire bonding of three-dimensional electrodeposition of metals and conductive polymer,a Direct Optical Wire(DOW)technique has been recently proposed. This technology utilizes the rapid volatilization of solvents in extruded polymer liquids to create arched polymer pathways for conducting light between single-mode fiber and gratings. However,the cross-section and path are not completely controllable and the accuracy is low,limiting the implementation of small interface and low transmission loss. Femtosecond laser has extremely high pulse power,which triggers the two-photon absorption at the focal point and cause crosslinking of the photoresist material. The two-photon absorption efficiency is proportional to the square of the light intensity,and the absorbed light intensity will rapidly decay with the distance from the focal point,so the resolution of Two-Photon Polymerization(TPP)can break the diffraction limit,with the lateral resolution below 100 nm. In addition,two-photon polymerization enables true three-dimensional,mask-free,and custom machining with high degrees of freedom,becoming an indispensable tool in the field of micro-nano additive manufacturing. In this paper, we review the field of laser additive manufacturing of on-chip optical components for photonic chip integration including Photonic Wire Bonding(PW

关 键 词：集成光学 增材制造 飞秒激光 双光子聚合 混合集成 光子引线键合 微空间光路元件 

分 类 号：TN256[电子电信—物理电子学]