Recently, at the 2025 Conference on Lasers and Electro-Optics (CLEO) held in Long Beach, USA, the research on a micro-transfer-printed lithium tantalate/silicon nitride heterogeneously integrated low-loss high-speed modulator by Professor Jianping Chen and Professor Linjie Zhou's group from the National Key Laboratory of Photonic Transmission and Communication was accepted as a Postdeadline Paper (PDP) and presented with an on-site oral presentation. Collaborators on this work include Professor Jinsong Xia's team from Huazhong University of Science and Technology and Professor Nan Chi's team from Fudan University.
The paper author delivering the presentation at the conference
Research Background
High-performance photonic chips are required to meet the demand for massive data transmission. However, a single integrated photonic platform—be it silicon, silicon nitride, III-V semiconductors, or thin-film lithium niobate/tantalate—cannot achieve fully functional and high-performance photonic chips. Existing solutions like hybrid integration, direct growth, and wafer bonding struggle to achieve low-cost, low-loss, multi-material heterogeneous integration. In recent years, micro-transfer printing has emerged as a significant heterogeneous integration solution due to its high flexibility.
Innovative Achievement
The research group proposed a comprehensive solution supporting the construction of fully functional and high-performance heterogeneously integrated photonic chips. Using micro-transfer printing technology, they integrated light sources, high-speed modulators, and photodetectors onto an ultra-low-loss silicon nitride platform. This work integrated a thin-film lithium tantalate device onto a commercially fabricated silicon nitride Mach-Zehnder Modulator (MZM) via micro-transfer printing, demonstrating for the first time a C-band lithium tantalate high-speed modulator on silicon nitride. Test results show an average MZM loss of approximately 0.82 dB, a coupling loss between the silicon nitride and the lithium tantalate/silicon nitride hybrid waveguide below 0.3 dB, and a transfer yield exceeding 94%. The modulator exhibits an electro-optic bandwidth exceeding 67 GHz and supports data rates up to 250 Gbit/s.
Development Prospects
Structure and test results of the heterogeneously integrated modulator
This research successfully achieved high-precision multi-material heterogeneous integration on a low-loss silicon nitride platform through micro-transfer printing technology. This progress not only breaks through the technical bottlenecks of traditional integration schemes but also opens a new path for the design and process preparation of future photonic chips. This work is significant for the development of intelligent computing centers and 6G communications, potentially significantly enhancing the optical communication capabilities of data centers and supporting optical interconnect systems with higher bandwidth and lower power consumption. By continuously optimizing the micro-transfer printing process, improving yield, and reducing costs, this technology is expected to achieve partial commercial application in fields such as high-speed optical communication and optical computing within the next 3-5 years, promoting the rapid development of optical communication and computing technologies.
Paper Information
Contributors to this work: Jinwei Su (Ph.D. candidate, SJTU Photonics NKLC), Yiqi Dai (Ph.D. candidate, HUST), Aolong Sun (Ph.D. candidate, Fudan University), Shihuan Ran (Ph.D. candidate, SJTU Photonics NKLC), Yuqin Yuan (Ph.D. candidate, Fudan University), Associate Professor Yu Li (Fixed Member, SJTU Photonics NKLC), Professor Jinsong Xia (HUST), Professor Nan Chi (Fudan University), Professor Jianping Chen (Fixed Member, SJTU Photonics NKLC), Professor Linjie Zhou (Fixed Member, SJTU Photonics NKLC). The corresponding authors are Associate Professor Liangjun Lu (Fixed Member, SJTU Photonics NKLC), Associate Researcher Cheng Zeng (HUST), and Professor Junwen Zhang (Fudan University).
Conference Information
CLEO is one of the most influential top-tier international conferences in the fields of optical communication and integrated photonics. The conference accepted over 1000 papers, including 37 PDP papers. PDP papers aim to publish the latest achievements with breakthrough technological progress in the field. This conference featured 3 PDP papers from domestic Chinese institutions.
Source: School of Integrated Circuits (School of Electronic Information and Electrical Engineering)
