Publications de Jijun He | EPFL Graph Search

Cascaded all-optical quantization employing step-size MMI and shape-optimized power splitter

Jijun He, Xiaowei Zhang, Jian Wu, Ye Tian

As a key unit of future high-throughput communications, optical analog to digital converter (OADC) with all-optical quantizer element that simultaneously possesses high resolution, large bandwidth and compact size is highly promising. A pending issue of co ...

ELSEVIER SCI LTD2023

Photo-induced cascaded harmonic and comb generation in silicon nitride microresonators

Tobias Kippenberg, Camille Sophie Brès, Jianqi Hu, Ozan Yakar, Junqiu Liu, Wenle Weng, Jijun He, Edgars Nitiss

Silicon nitride (Si3N4) is an ever-maturing integrated platform for nonlinear optics but mostly considered for third-order [chi(3)] nonlinear interactions. Recently, second-order [chi(2)] nonlinearity was introduced into Si3N4 via the photogalvanic effect, ...

2022

Low-noise frequency-agile photonic integrated lasers for coherent ranging

Tobias Kippenberg, Rui Ning Wang, Anat Siddharth, Viacheslav Snigirev, Junqiu Liu, Wenle Weng, Jijun He, Andrey Voloshin, Vladimir Shadymov

Stable and tunable integrated lasers are fundamental building blocks for applications from spectroscopy to imaging and communication. Here the authors present a narrow linewidth hybrid photonic integrated laser with low frequency noise and fast linear wave ...

Nature Portfolio2022

Microresonator Dissipative Kerr Solitons Synchronized to an Optoelectronic Oscillator

Tobias Kippenberg, Wenle Weng, Jijun He

Using phase-modulation-induced potential gradient whose period is synchronized to a microwave opto-electronic oscillator, dissipative Kerr solitons generated in a crystalline optical microresonator are trapped by the soliton tweezing effect, exhibiting a s ...

American Physical Society (APS)2022

Time-continuous Travelling-Wave Optical Parametric Amplification in a Photonic Circuit

Tobias Kippenberg, Rui Ning Wang, Nikolai Kuznetsov, Junqiu Liu, Jijun He

We demonstrate a traveling wave parametric amplifier in a photonic Si3N4 integrated spiral waveguide of 2.0 m length with footprint 3x5 mm. We achieve net gain of 7 dB on-chip and 2 dB fiberto-fiber in the optical C-band. (C) 2022 The Author(s) ...

IEEE2022

A Photonic Integrated Circuit-Based Erbium-doped Waveguide Amplifier

Tobias Kippenberg, Rui Ning Wang, Xinru Ji, Zheru Qiu, Junqiu Liu, Jijun He, Yang Liu

We demonstrate an erbium-doped waveguide amplifier by erbium ion implantation in Si3N4 photonic integrated circuits, achieving 145 mW on-chip output power and more than 30 dB small-signal gain, which is on par with commercial fiber amplifiers and beyond st ...

IEEE2022

A photonic integrated continuous-travelling-wave parametric amplifier

Tobias Kippenberg, Rui Ning Wang, Nikolai Kuznetsov, Junqiu Liu, Jijun He

The ability to amplify optical signals is of pivotal importance across science and technology typically using rare-earth-doped fibres or gain media based on III-V semiconductors. A different physical process to amplify optical signals is to use the Kerr no ...

NATURE PORTFOLIO2022

A photonic integrated circuit-based erbium-doped amplifier

Tobias Kippenberg, Rui Ning Wang, Xinru Ji, Zheru Qiu, Junqiu Liu, Jijun He, Yang Liu, Anton Lukashchuk

Erbium-doped fiber amplifiers revolutionized long-haul optical communications and laser technology. Erbium ions could provide a basis for efficient optical amplification in photonic integrated circuits but their use remains impractical as a result of insuf ...

American Association for the Advancement of Science2022

Compact, Spatial-mode-interaction-free, Ultralow-loss, Nonlinear photonic integrated circuits

Tobias Kippenberg, Rui Ning Wang, Xinru Ji, Zheru Qiu, Junqiu Liu, Jijun He

We implement Euler bends to build compact high-Q Si3N4 racetrack microresonators, featuring a small footprint of only 0.21 mm(2) for 19.8 GHz FSR. We demonstrate that these multi-mode microresonators can be operated in the single-mode regime and generate a ...

IEEE2022

Platicon microcomb generation using laser self-injection locking

Tobias Kippenberg, Rui Ning Wang, Junqiu Liu, Wenle Weng, Jijun He, Yang Liu, Miles Henry Anderson

The past decade has witnessed major advances in the development and system-level applications of photonic integrated microcombs, that are coherent, broadband optical frequency combs with repetition rates in the millimeter-wave to terahertz domain. Most of ...

Nature Portfolio2022