Publications de Zihan Li | EPFL Graph Search

Frequency Conversion in Periodically Poled Thin-Film Lithium Tantalate Photonic Integrated Circuits

Tobias Kippenberg, Nikolai Kuznetsov, Zihan Li

Second-order optical nonlinear processes, such as second harmonic generation, difference-frequency generation, or sum-frequency generation, find numerous applications in laser science, quantum technology, sensing, photonic computing, and many other areas. ...

IEEE2025

High-Energy Mode-Locked Pulses from a Photonic Integrated Mamyshev Oscillator

Tobias Kippenberg, Grigorii Likhachev, Jianqi Hu, Xinru Ji, Zheru Qiu, Zihan Li

Mode-locked lasers (MLLs), capable of generating ultrashort coherent pulses, have been instrumental for numerous applications, including optical frequency metrology, eye surgery, machining, additive manufacturing, imaging and spectroscopy. However, commerc ...

IEEE2025

Observation of Fundamental Charge Noise in Electro-Optic Photonic Integrated Circuits

Tobias Kippenberg, Guanhao Huang, Zihan Li, Junyin Zhang

We observed that Lithium Niobate and Lithium Tantalate photonic integrated microresonators exhibit an unexpected Flicker type (i.e. 1/f1.2) scaling in the intrinsic refractive noise spectrum, significantly deviating from the well-established thermorefracti ...

Springer Science and Business Media Deutschland GmbH2024

Lithium tantalate photonic integrated circuits for high volume manufacturing

Tobias Kippenberg, Mikhail Churaev, Xinru Ji, Zihan Li

We demonstrate the first photonic integrated circuit platform using Lithium Tantalate (LiTaO3), achieving waveguides with low losses (5.6 dB m−1), Mach-Zehnder modulators with a 40 GHz electro-optical bandwidth and a 1.96 V · cm voltage-length product, alo ...

Institute of Electrical and Electronics Engineers Inc.2024

Low-temperature and hydrogen-free silicon dioxide cladding for next-generation integrated photonics

Tobias Kippenberg, Xinru Ji, Anat Siddharth, Zheru Qiu, Zihan Li

We demonstrate a process for hydrogen-free low-loss silicon oxide (SiO2) films deposited using S iCl4 and O 2 as precursors. A wide low-loss window from 1260 nm to 1625 nm is achieved at a deposition temperature of 300 ◦C, essential for next generation pho ...

Optical Society of America2024

Ultrabroadband Integrated Triply Resonant Electro-Optic Frequency Comb in Lithium Tantalate

Tobias Kippenberg, Jianqi Hu, Mikhail Churaev, Nikolai Kuznetsov, Zihan Li, Junyin Zhang

We demonstrated an integrated electro-optic frequency comb generator with 450nm span and 29.6GHz spacing, entirely covering optical telecom E-, S-, C-, L-, and U-bands, via monolithic co-integration of microwave and photonics resonators on thin-film lithiu ...

Optica Publishing Group (formerly OSA)2024

Lithium Tantalate Photonic Integrated Circuits (Student Paper)

Tobias Kippenberg, Mikhail Churaev, Xinru Ji, Zihan Li

We demonstrate a wafer-scale lithium tantalate photonic platform with loss as low as 5.5 dB m(-1). Mach-Zehnder modulators with a 40 GHz electro-optical bandwidth and a 1.96 V center dot cm voltage-length product, along with microresonators supporting diss ...

Springer Nature2024

Observation of Fundamental Charge Noise in Electro-Optic Photonics Integrated Circuits

Tobias Kippenberg, Guanhao Huang, Zihan Li, Junyin Zhang

We observed a novel 1/f-type frequency noise in Lithium Niobate and Lithium Tantalate microresonators, distinct from thermorefractive noise and originating from thermodynamic charge fluctuations, setting the linewidth limits for integrated lasers. A charge ...

Optica Publishing Group (formerly OSA)2024

Duv photolithography electrode fabrication method and electrode produced using the method

Tobias Kippenberg, Zihan Li

DUV photolithography compatible electrode fabrication method comprising providing at least one material surface to which at least one electrode is to be attached; providing at least one undercut non-photoresist material or support between the at least one ...

2024

Lithium tantalate photonic integrated circuits for volume manufacturing

Tobias Kippenberg, Kai Huang, Chen Yang, Mikhail Churaev, Xinru Ji, Yang Chen, Zihan Li, Alisa Davydova, Xi Wang, Junyin Zhang

Electro-optical photonic integrated circuits (PICs) based on lithium niobate (LiNbO3) have demonstrated the vast capabilities of materials with a high Pockels coefficient1,2. They enable linear and high-speed modulators operating at complementary metal–oxi ...

2024

Ultrabroadband thin-film lithium tantalate modulator for high-speed communications

Tobias Kippenberg, Mikhail Churaev, Zihan Li, Junyin Zhang

The continuous growth of global data traffic over the past three decades, along with advances in disaggregated computing architectures, presents significant challenges for optical transceivers in communication networks and high-performance computing system ...

2024

Low temperature optical waveguide device fabrication method

Tobias Kippenberg, Zheru Qiu, Zihan Li

The present invention concerns an optical waveguide device fabrication method comprising providing at least one optical waveguide or optical waveguide core; and depositing at least one silicon dioxide layer or material onto the at least one optical wavegui ...

2024

High-density lithium niobate integrated photonics

Tobias Kippenberg, Mikhail Churaev, Anat Siddharth, Zihan Li

We demonstrate a strip waveguide-based LiNbO3 photonic integrated circuit fabricated with a novel hard mask, diamond-like-carbon (DLC). The steep sidewall configuration exhibits tight optical confinement and dispersion control while preserving ultra-low lo ...

Optical Society of America2023

Low-temperature and hydrogen-free silicon dioxide cladding for integrated photonics

Rui Ning Wang, Tobias Kippenberg, Zheru Qiu, Zihan Li

We demonstrate a hydrogen-free low-loss silicon oxide film deposited with SiCl4 and O2 precursor. A very wide low-loss window of 1300 nm to 1620 nm is achieved at deposition temperature as low as 300 ◦C. ...

Optical Society of America2023

High density lithium niobate photonic integrated circuits

Rui Ning Wang, Tobias Kippenberg, Mikhail Churaev, Anat Siddharth, Zelin Tan, Nikolai Kuznetsov, Zihan Li, Junyin Zhang

Photonic integrated circuits have the potential to pervade into multiple applications traditionally limited to bulk optics. Of particular interest for new applications are ferroelectrics such as Lithium Niobate, which exhibit a large Pockels effect, but ar ...

Nature Portfolio2023

Reduced material loss in thin-film lithium niobate waveguides

Tobias Kippenberg, Di Zhu, Guanhao Huang, Mikhail Churaev, Zihan Li

Thin-film lithium niobate has shown promise for scalable applications ranging from single-photon sources to high-bandwidth data communication systems. Realization of the next generation high-performance classical and quantum devices, however, requires much ...

AIP Publishing2022