Publications de Junqiu Liu | EPFL Graph Search

Search for Scalar Leptoquarks Produced via τ-Lepton-Quark Scattering in pp Collisions at ffiffi s p=13 TeV

Rakesh Chawla, Andrea Rizzi, Matthias Finger, Federica Legger, Matteo Galli, Sun Hee Kim, João Miguel das Neves Duarte, Tagir Aushev, Hua Zhang, Alexis Kalogeropoulos, Yixing Chen, Tian Cheng, Ioannis Papadopoulos, Gabriele Grosso, Valérie Scheurer, Meng Xiao, Qian Wang, Michele Bianco, Varun Sharma, Joao Varela, Marko Stamenkovic, Sourav Sen, Ashish Sharma, Seungkyu Ha, David Vannerom, Csaba Hajdu, Sanjeev Kumar, Sebastiana Gianì, Kun Shi, Abhisek Datta, Siyuan Wang, Junqiu Liu, Anton Petrov, Jian Wang, Yi Zhang, Muhammad Ansar Iqbal, Yong Yang, Xin Sun, Muhammad Ahmad, Donghyun Kim, Matthias Wolf, Anna Mascellani, , , , , , , , , , , , , , , , , , , , , ,

Search for new Higgs bosons via same-sign top quark pair production in association with a jet in proton-proton collisions at √s=13 TeV

Rakesh Chawla, Andrea Rizzi, Matthias Finger, Federica Legger, Matteo Galli, Sun Hee Kim, João Miguel das Neves Duarte, Tagir Aushev, Hua Zhang, Alexis Kalogeropoulos, Yixing Chen, Tian Cheng, Ioannis Papadopoulos, Gabriele Grosso, Valérie Scheurer, Meng Xiao, Qian Wang, Michele Bianco, Varun Sharma, Joao Varela, Marko Stamenkovic, Sourav Sen, Ashish Sharma, Seungkyu Ha, David Vannerom, Csaba Hajdu, Sanjeev Kumar, Sebastiana Gianì, Kun Shi, Abhisek Datta, Siyuan Wang, Junqiu Liu, Anton Petrov, Jian Wang, Yi Zhang, Muhammad Ansar Iqbal, Yong Yang, Xin Sun, Muhammad Ahmad, Donghyun Kim, Matthias Wolf, Anna Mascellani, , , , , , , , , , , , , , , , , , , ,

UV, visible and near-infrared light generation through cascaded nonlinear processes in silicon-nitride microring resonators pumped at telecom wavelength

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Boris Zabelich, Marco Clementi

On-chip coherent light generation has wide-ranging applications in metrology, spectroscopy, quantum optics, etc. In this study, we demonstrate the generation of coherent light from a silicon-nitride microring resonator using cascaded nonlinear processes. T ...

SPIE2024

Coupling Free Electrons and Cavity Photons in a Transmission Electron Microscope

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Guanhao Huang, Zheru Qiu, Yujia Yang

We couple free electrons to the optical modes of a photonic microring resonator. Inelastic electron scattering leads to the generation of cavity photons, correlated to the electrons in time and energy loss. ...

Institute of Electrical and Electronics Engineers Inc.2024

Toward Quantum Networking with Frequency-Bin Qudits

Tobias Kippenberg, Junqiu Liu

Quantum networking holds tremendous promise in transforming computation and communication. Entangled-photon sources are critical for quantum repeaters and networking, while photonic integrated circuits are vital for miniaturization and scalability. In this ...

SPIE2024

Architecture for integrated RF photonic downconversion of electronic signals

Tobias Kippenberg, Junqiu Liu

Electronic analog to digital converters (ADCs) are run-ning up against the well-known bit depth versus bandwidth trade off. Towards this end, radio frequency (RF) photonic-enhanced ADCs have been the subject of interest for some time. Optical frequency com ...

Optica Publishing Group2023

Lithium-niobate-based narrow-linewidth frequency agile integrated lasers with petahertz frequency tuning rate

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Guanhao Huang, Mikhail Churaev, Anat Siddharth, Viacheslav Snigirev

We demonstrate an electro-optically tunable hybrid integrated laser self-injection locked to a mode of a heterogeneously integrated lithium-niobate-on-Damascene-silicon-nitride microresonator. An intrinsic linewidth of 3 kHz and a frequency tuning rate of ...

IEEE2023

Sub-kHz-Linewidth External-Cavity Laser (ECL) With Si3N4 Resonator Used as a Tunable Pump for a Kerr Frequency Comb

Tobias Kippenberg, Junqiu Liu

Combining optical gain in direct-bandgap III-V materials with tunable optical feedback offered by advanced photonic integrated circuits is key to chip-scale external-cavity lasers (ECL), offering wideband tunability along with low optical linewidths. Exter ...

IEEE Institute of Electrical and Electronics Engineers2023

A heterogeneously integrated lithium niobate-on-silicon nitride photonic platform

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Miles Henry Anderson, Mikhail Churaev, Anat Siddharth, Viacheslav Snigirev

The availability of thin-film lithiumniobate on insulator (LNOI) and advances in processing have led to the emergence of fully integrated LiNbO3 electro-optic devices. Yet to date, LiNbO3 photonic integrated circuits have mostly been fabricated using non-s ...

Nature Portfolio2023

A High-Resolution Photonic Integrated High Q Microresonator Based Accelerometer

Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Anat Siddharth

We demonstrated a packaged optomechanical accelerometer with resolution of 850ng. The resonance of a 4 million Q Si3N4 microring resonator is modulated by the stress in springs of a released milligram proof mass upon acceleration. ...

Optical Society of America2023

Time-Resolved Hanbury Brown-Twiss Interferometry of On-Chip Biphoton Frequency Combs Using Vernier Phase Modulation

Tobias Kippenberg, Junqiu Liu

Biphoton frequency combs (BFCs) are promising quantum sources for large-scale and high-dimensional quantum information and networking systems. In this context, the spectral purity of individual frequency bins will be critical for realizing quantum networki ...

American Physical Society (APS)2023

Chaotic microcomb-based parallel ranging

Tobias Kippenberg, Junqiu Liu, Anton Lukashchuk, Aleksandr Tusnin

The intrinsic random amplitude and phase modulation of 40 distinct lines of a microresonator frequency comb operated in the modulation instability regime are used to realize massively parallel random-modulation continuous-wave light detection and ranging, ...

Nature Publishing Group2023

A chip-scale second-harmonic source via self-injection-locked all-optical poling

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Edgars Nitiss, Marco Clementi

Second-harmonic generation allows for coherently bridging distant regions of the optical spectrum, with applications ranging from laser technology to self-referencing of frequency combs. However, accessing the nonlinear response of a medium typically requi ...

2023

Self-injection Locked Second-Harmonic Generation in Optically Poled Silicon Nitride Microresonators

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Edgars Nitiss, Marco Clementi

We present a narrow-linewidth second-harmonic source based on a laser diode injection locked to an optically poled silicon nitride microresonator. The device is a compact, highly-coherent dual-wavelength source, with high conversion efficiency up to 280%/W ...

2023

Photon Fock State Generation in Photonic Microresonators

Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Guanhao Huang, Zheru Qiu, Yujia Yang

We generate correlated pairs of free electrons and cavity photons by sending an electron beam across a photonic microresonator and filtering temporal coincidences. We further characterize the pairs analogue to a heralded single photon source. ...

Optical Society of America2023

Towards efficient broadband parametric conversion in ultra-long Si3N4 waveguides

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Arman Ayan

Broadband continuous-wave parametric gain and efficient wavelength conversion is an important functionality to bring on-chip. Recently, meter-long silicon nitride waveguides have been utilized to obtain continuous-traveling-wave parametric gain, establishi ...

Optica Publishing Group2023

Ultrafast tunable lasers using lithium niobate integrated photonics

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Guanhao Huang, Mikhail Churaev, Anat Siddharth, Viacheslav Snigirev

Early works(1) and recent advances in thin-film lithium niobate (LiNbO3) on insulator have enabled low-loss photonic integrated circuits(2,3), modulators with improved half-wave voltage(4,5), electro-optic frequency combs(6) and on-chip electro-optic devic ...

NATURE PORTFOLIO2023

Search for relativistic fractionally charged particles in space

Songmei Wu, Johan Juul Chang, Zhirui Xu, Jennifer Maria Frieden, Siyuan Wang, Junqiu Liu, Jian Wang, Yi Zhang, Yong Yang, Hao Liu, Ming Gao, Cheng Zhao, Xuan Li, Arshia Ruina, Chiara Perrina, Andrii Kotenko, Wenyu Zhang, Xiao Wang, Yi Wang, Wei Li, Jie Chen, Shuai Liu, Yao Zhang

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles (FCPs) still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Mos ...

American Physical Society2022

Lithium-Niobate-Based Frequency-Agile Integrated Lasers

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Grigorii Likhachev, Guanhao Huang, Mikhail Churaev, Anat Siddharth, Viacheslav Snigirev

We demonstrate narrow- linewidth ultrafast tunable integrated lasers based on heterogeneously integrated thin-film lithium niobate on ultra-low loss silicon nitride integrated photonic circuits. Using self-injection locking of a hybrid microresonator, we a ...

IEEE2022

Continuous-Wave Four-Wave Mixing Efficiency-Bandwidth Tradeoff Study in Meter-Long Silicon Nitride Waveguides

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Arman Ayan

Continuous-wave four-wave mixing conversion efficiency-bandwidth trade-off in silicon nitride waveguides is investigated to reach efficient and broadband wavelength conversion. Additionally, parametric gain and efficient cascaded four-wave mixing is observ ...

2022