• Light Interconnects Laboratory
    School of Microelectronics
    Southern University of Science and Technology
  • About LICONLAB

    LICONLAB (Light Interconnects Laboratory) is an academic research laboratory founded by Dr. Qiancheng Zhao in the School of Microelectronics at Southern University of Science and Technology (SUSTech). The Lab specializes in integrated photonics research in high-tech areas such as next-generation optical communications, integrated lasers, nonlinear photonics, and quantum photonics applications.

     

    Dr. Qiancheng Zhao is currently an assistant professor in the School of Microelectronics at the Southern University of Science and Technology (SUSTech). Prior to joining SUSTech, he worked at the University of California, Santa Barbara as a postdoctoral researcher, and at Apple Inc. as a signal integrity engineer. He obtained his Ph.D. degree from the University of California, Irvine, and bachelor's degree from Zhejiang University.

  • News

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    [2024/09/12] Our paper was awarded as a Best Paper in the IEEE OGC Conference

    Dr. Zhao represented the authors to accept the award. The first and second authors are Zhenyu Liu and Xiaolun Yu. The award presenter is Rene-Jean Essiambre. He is a Bell Labs Fellow and was the former president of the IEEE Photonics Society.

    This paper will be indexed in IEEE Xplore.

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    [2024/08/30] Our paper was published in Optics Express

    We extend the range of coupling strengths to a full description and propose a new approach to delineate the spectral response of the interactions between the χ(2) and χ(3) nonlinearities. Critically, the underpinned physics is enabled by avoided mode crossing (AMX) in concentric double-ring microresonators. We demonstrate that the evolution of the anti-symmetric mode at fundamental wavelengths disrupts spectral symmetry, leading to asymmetric χ(2)-translated optical frequency combs at second-harmonic wavelengths. Simultaneous generation of skewed two-color optical frequency combs is numerically realized in an exemplary gallium phosphide-on-insulator platform with a coupling constant from 133.3 m-1W-1/2 to 7.4 m-1W-1/2, showing reasonable agreement with our theoretical model. Our findings provide a novel approach to shaping the optical frequency comb, which may facilitate potential applications in self-referencing and frequency metrology with desired comb spectral shapes.

    The paper can be accessed on Optics Express website.

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    [2024/06/02] Zhaoting Geng successfully had his Bachelor's degree defense.

    His thesis title is "Low-loss Tantalum Pentoxide Photonic Platform". His journal paper has been published already.

    Congratulations to Zhaoting!

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    [2024/05/10] Pengzhuo Wu successfully had his M.S. thesis defense.

    His thesis title is "Investigation of Gallium Phosphide-on-Insulator Microcomb Resonators based on Cascaded Second-Order and Third-Order Nonlinearity".

    Congratulations to Pengzhuo!

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    [2024/03/20] Our paper was published in Optics Express

    We report a Ta2O5 photonic platform with a propagation loss of 0.49 dB/cm at 1550 nm, of 0.86 dB/cm at 780 nm, and of 3.76 dB/cm at 2000 nm. The thermal bistability measurement is conducted in the entire C-band for the first time to reveal the absorption loss of Ta2O5 waveguides, offering guidelines for further reduction of the waveguide loss. We also characterize the Ta2O5 waveguide temperature response, which shows favorable thermal stability. The fabrication process temperature is below 350°C, which is friendly to integration with active optoelectronic components.

    The paper can be accessed on Optics Express website.

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    [2024/02/13] Our paper was published in IEEE Photonics Journal

    We describe a synergistic optimization approach that enables highly efficient frequency translation of a Kerr optical frequency comb (OFC) from 1550 nm to 775 nm in a gallium phosphide-on-insulator (GaP-OI) microresonator. Key distinctions from previous GaP-OI works which focused on individual optical nonlinearity are that this work not only emphasizes the interaction between the second- and third-order nonlinearity, but also explores the tunability of the χ(2)-translated OFC through geometric and temperature tuning. The sum-frequency (SF) comb at 775 nm has a geometric tuning sensitivity of 354 GHz/nm, and a thermal tuning sensitivity of 24.8 GHz/K, paving the way for post-fabrication trimming and in-situ spectral shaping, with a broader potential to realize highly efficient, wide-spectrum, and tunable on-chip nonlinear sources.

    The paper can be accessed on IEEE Photonics Journal website.

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    [2022/06/30] Call for Papers! The "Integrated Waveguide-Based Photonic Devices" special issue is now open for submission!

    This Special Issue focuses on the state-of-the-art achievements in integrated waveguide-based photonic devices, with a broader aim to present novel material, design methodology, and fabrication techniques as well as cutting-edge applications.

    The submission deadline is June 30, 2023. More submission information can be found here.

  • RESEARCH

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    Tantalum pentoxide photonic devices

    Tantalum pentoxide is a versatile photonic material that is compatible with silicon photonics. It has a moderate refractive index, low propagation loss, a non-negligible third-order nonlinearity, a small thermo-optic coefficient, and a low Raman background. Thus it is widely used in passive photonic devices for optical interconnecting, nonlinearity, and bio-photonic applications. Integrating functional components empowers tantalum pentoxide passive devices with unprecedented functionalities that could only be realized in active photonic devices, such as modulators, detectors, etc., opening new possibilities for a whole new class of integrated devices and systems.

     

    Our group has rich experience in fabricating low-loss tantalum pentoxide waveguides, high-Q resonators, and athermal photonic devices.

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    Nonlinear integrated photonic devices

    Nonlinear integrated photonics plays important roles in optical communications, sensing, spectroscopy, etc. Numerous nonlinear devices such as light sources, modulators, and sensors have been demonstrated thanks to the rich optical nonlinear mechanisms. Miniaturization of the photonic devices not only reduces the cost but also makes complex systems suitable for portable and field deployed applications. On-chip photonic integration is an enabling factor to miniaturize nonlinear optical devices. With the development of highly nonlinear photonic integration platform, novel on-chip nonlinear devices will emerge with unprecedent performance, and will find useful in quantum photonics, machine learning, optical neuron computing and other leading-edge applications.

     

    Our group focuses on the frequency comb generation, second harmonic generation, supercontinuum generation and related nonlinear phenomena in the emerging gallium phosphide-on-insulator platform.

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    On-chip optical reference cavities

    Optical reference cavities are essential components in laser linewidth narrowing and frequency stabilization. Once tightly locked to a frequency reference, the frequency stability of the laser is determined by the stability of the cavity. Traditional benchtop Fabry-Perot reference cavities occupy a large operation space. It is desirable to miniaturize these cavities harnessing the photonic integrated waveguide-based technologies, which may foster a blossom of integrated narrow linewidth lasers.

     

    Our group study the frequency stability of on-chip microresonators and their applications in laser frequency locking. The research topics cover the athermal waveguides, high-Q resonators, frequency locking systems, temperature sensing techniques, and related areas.

  • TEAM

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    Qiancheng Zhao

    赵前程

    PI

    zhaoqc@sustech.edu.cn

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    Weiren Cheng

    程炜仁

    PhD

    12231169@mail.sustech.edu.cn

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    Zhenyu Liu

    刘振宇

    PhD

    12331328@mail.sustech.edu.cn

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    Jiaxin Hou

    侯甲欣

    PhD

    jiaxin_hou@163.com

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    Ning Ding

    丁宁

    Master

    12333314@mail.sustech.edu.cn

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    Xingyu Tang

    汤星宇

    Master

    12333287@mail.sustech.edu.cn

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    Mingjian You

    游铭坚

    Master

    12333354@mail.sustech.edu.cn

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    Junke Zhou

    周峻珂

    Master

    12011712@mail.sustech.edu.cn

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    Xiaolun Yu

    余晓伦

    Bachelor

    12111824@mail.sustech.edu.cn

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    Yihan Liu

    刘逸涵

    Bachelor

    12111914@mail.sustech.edu.cn

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    Jiazhao He

    何家兆

    Bachelor

    12211729@mail.sustech.edu.cn

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    Naiqin Bu

    布乃勤

    Bachelor

    12211204@mail.sustech.edu.cn

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    Yiming Zhou

    周一鸣

    Bachelor

    12211740@mail.sustech.edu.cn

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    Ke Zhu

    朱柯

    Bachelor

    12212931@mail.sustech.edu.cn

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    Rui Qiu

    邱瑞

    Secretary

    qiur@mail.sustech.edu.cn

  • PUBLICATIONS

    Invited Talks

    • Qiancheng Zhao, “Integrated Gallium Phosphide-on-Insulator Devices for Nonlinear Photonics”, Forum on Photonic Integrated Circuits, Xiamen, 2023 (Invited)
    • Qiancheng Zhao, “On-chip Optical Reference Cavities”, IEEE the 7th Optoelectronics Global Conference (OGC 2022), Shenzhen, 2022 (Invited)
    • Qiancheng Zhao, “Waveguide-based Optical Reference Cavities”,  2022 Asia Communications and Photonics Conference (ACP 2022), Shenzhen, 2022 (Invited)
    • Qiancheng Zhao, "Photonic Integrated Optical Reference Cavity", Zhuoyue Quantum Salon,  Institute for Quantum Science and Engineering, Shenzhen, 2022 (Invited)
    • Qiancheng Zhao, “Integrated optical reference cavity for laser frequency stabilization”, IEEE the 6th Optoelectronics Global Conference (OGC 2021), Shenzhen, 2021 (Invited)

    Books/Chapters

    Edited by Ozdal Boyraz and Qiancheng Zhao, Silicon Photonics Bloom, ISBN 978-3-03936-908-9, MDPI AG, 2020

    Recent Journal Publications

    Recent Conference Publications

  • CONTACT

    Openings

    We are looking for self-motivated PhD, master, and undergraduate students to join our team. Postdocs and visiting scholars are also welcome. Candidates will work in integrated photonic devices and systems, including device design and simulation, cleanroom fabrication, lab automation and characterization. Specific research topics will be determined based on the common interests of the candidate and the advisor.

    Preferred applicant profile:

    - Self-motivated and can-do attitude.

    - Has optics, physics, electrical engineering, or related education background.

    - Proficiency in MATLAB/Python programming.

    - Knowledge of Lumerical/COMSOL or equivalent software is a plus.

    Contact Information

    Email: zhaoqc AT sustech DOT edu DOT cn

    Location: Building 3, Nanshan iPark Chongwen, Nanshan District, Shenzhen, Guangdong, China, 518055

     

  • ALUMNI

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    Houling Ji

    姬厚领

    Graduated in 2023 with a master's degree

    After graduation: Joint PhD of SUSTech and Pengcheng Lab

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    Zhuoyu Yu

    余卓宇

    Graduated in 2024 with a bachelor's degree

    After graduation: Research Assistant

     

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    Zhaoting Geng

    耿兆珽

    Graduated in 2024 with a bachelor's degree

    After graduation: PhD in Hong Kong University

     

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    Pengzhuo Wu

    吴鹏焯

    Graduated in 2024 with a master's degree

    After graduation: BYD Company