Lithium Niobate Nanophotonics

Photonic integrated circuit (PIC) technology holds great potential for breaking through the bottlenecks in current photonic and optoelectronic networks. Recently, a revolution has been witnessed in the field of lithium niobate (LN) photonics. Over the past decade, nanoscale LN waveguides with a propagation loss of ~0.01 dB and a radius of curvature on the level of ~100 µm have been demonstrated. The revolution mainly benefits from two technological advancements, the maturity of lithium-niobate-on-insulator (LNOI) technology and the innovation of nanofabrication approaches of high-quality LNOI photonic structures. Using low-loss waveguides and high-quality-factor (high-Q) microresonators produced on the LNOI platform as building blocks, various integrated photonic devices have been demonstrated with unprecedented performances. The breakthroughs have reshaped the landscape of the LN industry. This is the first monograph on LN nanophotonics enabled by the LNOI platform. It comprehensively reviews the development of fabrication technology, investigations on nonlinear optical processes, and demonstrations of electro-optical devices, as well as applications in quantum light sources, spectroscopy, sensing, and microwave-to-optical wave conversion. The bookbegins with an overview of the technological evolution of PICs, justifying the motivation for developing LNOI photonics. The next four chapters focus on LNOI photonics. The book concludes with a summary of the milestone achievements discussed in these chapters and provides a future perspective of this area of research.

1 Introduction 2 Fabrication Technology of Photonic Structures on Lithium-Niobate-on-Insulator 3 Nonlinear Optics in Nanostructures Fabricated on Lithium-Niobate-on-Insulator 4 Integrated Electro-Optic Devices on Lithium-Niobate-on-Insulator 5 Integrated Photonics on Lithium-Niobate-on-Insulator: Toward Real-World Applications 6 Summary and Future Perspectives

Ya Cheng is Professor and Dean of the School of Physics and Electronic Science, East China Normal University, and Professor at the Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences. He obtained his BS from Fudan University, Shanghai, in 1993 and PhD from the SIOM in 1998. He developed slit-beam and spatiotemporal shaping techniques of femtosecond laser pulses for improving the spatial resolution in 3D micromachining, as well as photolithography-assisted chemomechanical etching for fabricating densePICs on LN. Professor Cheng has co-authored more than 200 peer-reviewed articles and co-authored/co-edited 5 books. He has given ~150 invited talks at international conferences and served as the chair or committee member of numerous international conferences. He is also a fellow of the Institute of Physics, UK.