Publications by Tianyi Liu | EPFL Graph Search

High-yield, wafer-scale fabrication of ultralow-loss, dispersion-engineered silicon nitride photonic circuits

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Nils Johan Engelsen, Guanhao Huang, Jijun He, Tianyi Liu

Low-loss photonic integrated circuits and microresonators have enabled a wide range of applications, such as narrow-linewidth lasers and chip-scale frequency combs. To translate these into a widespread technology, attaining ultralow optical losses with est ...

Nature Research2021

Monolithic piezoelectric control of soliton microcombs

Rui Ning Wang, Tobias Kippenberg, Erwan Guillaume Albert Lucas, Junqiu Liu, Miles Henry Anderson, Arslan Sajid Raja, Wenle Weng, Jijun He, Tianyi Liu

High-speed actuation of laser frequency(1)is critical in applications using lasers and frequency combs(2,3), and is a prerequisite for phase locking, frequency stabilization and stability transfer among optical carriers. For example, high-bandwidth feedbac ...

NATURE PUBLISHING GROUP2020

Integrated turnkey soliton microcombs

Rui Ning Wang, Tobias Kippenberg, Chao Xiang, Junqiu Liu, Jijun He, Tianyi Liu

Optical frequency combs have a wide range of applications in science and technology(1). An important development for miniature and integrated comb systems is the formation of dissipative Kerr solitons in coherently pumped high-quality-factor optical micror ...

NATURE RESEARCH2020

Integrated turnkey soliton microcombs operated at CMOS frequencies

Rui Ning Wang, Tobias Kippenberg, Chao Xiang, Junqiu Liu, Jijun He, Tianyi Liu

We experimentally discovered and theoretically explain a novel turnkey regime for operation of soliton microcombs, wherein a new operating point enables the direct access of the soliton state by simple turn-on of the pump laser. (C) 2020 The Author(s) ...

IEEE2020

Hybrid Si3N4-LiNbO3 integrated platform for electro-optic conversion

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Mikhail Churaev, Tianyi Liu

We demonstrate the integration of a Si3N4 Damascene photonic platform with thin-film lithium niobate on insulator (LNOI) via direct wafer bonding. This process enables fabrication of hybrid chi((2))-chi((3)) microresonators with Q similar to 10(6), as well ...

IEEE2020

Monolithic piezoelectric control of integrated soliton microcombs

Rui Ning Wang, Tobias Kippenberg, Erwan Guillaume Albert Lucas, Junqiu Liu, Miles Henry Anderson, Arslan Sajid Raja, Wenle Weng, Jijun He, Tianyi Liu

We demonstrate piezoelectric actuators monolithically integrated on ultralow-loss Si3N4 waveguides. Varying the voltage applied on the actuator allows tuning the microresonator, and is used to initiate, switch, stabilize and tightly phase lock the single s ...

IEEE2020

Optically Probed Time Dynamics of χ(2) Grating Inscription in SiN Waveguides

Tobias Kippenberg, Camille Sophie Brès, Davide Grassani, Edgars Nitiss, Tianyi Liu

Silicon Nitride (S13N4) waveguide platforms have seen significant interest in the recent years, motivated by several advantageous properties such as compatibility with CMOS fabrication standards, low propagation loss, high refractive index and optical nonl ...

2019

Formation Rules and Dynamics of Photoinduced χ(2) Gratings in Silicon Nitride Waveguides

Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Camille Sophie Brès, Davide Grassani, Edgars Nitiss, Tianyi Liu

Silicon nitride has emerged as a prominent platform for building photonics integrated circuits. While its nonlinear properties based on third-order effects have been successfully exploited, an efficient second harmonic generation in standard stoichiometric ...

2020