News
[2024/10/11] Dr. Zhao was awarded as an Excellent Mentor in the 2024 National Undergraduate Training Program for Innovation and Entrepreneurship
Mr. Zhaoting Geng was the implementor of the project under the supervision of Dr. Zhao. His project is "Study of the Gallium Phosphide Integrated Nonlinear Photonic Devices for Kerr Optical Frequency Comb Generation".
This project was awarded as one of the 15 best projects in the School of Engineering at SUSTech in 2024.
[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.
[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.
[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!
[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!
[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.
[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.
[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
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.
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.
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
Qiancheng Zhao
赵前程
PI
zhaoqc@sustech.edu.cn
Weiren Cheng
程炜仁
PhD
12231169@mail.sustech.edu.cn
Zhenyu Liu
刘振宇
PhD
12331328@mail.sustech.edu.cn
Jiaxin Hou
侯甲欣
PhD
jiaxin_hou@163.com
Ning Ding
丁宁
Master
12333314@mail.sustech.edu.cn
Xingyu Tang
汤星宇
Master
12333287@mail.sustech.edu.cn
Mingjian You
游铭坚
Master
12333354@mail.sustech.edu.cn
Junke Zhou
周峻珂
Master
12011712@mail.sustech.edu.cn
Xiaolun Yu
余晓伦
Bachelor
12111824@mail.sustech.edu.cn
Yihan Liu
刘逸涵
Bachelor
12111914@mail.sustech.edu.cn
Jiazhao He
何家兆
Bachelor
12211729@mail.sustech.edu.cn
Naiqin Bu
布乃勤
Bachelor
12211204@mail.sustech.edu.cn
Yiming Zhou
周一鸣
Bachelor
12211740@mail.sustech.edu.cn
Ke Zhu
朱柯
Bachelor
12212931@mail.sustech.edu.cn
Rui Qiu
邱瑞
Secretary
qiur@mail.sustech.edu.cn
ALUMNI
Houling Ji
姬厚领
Graduated in 2023 with a master's degree
After graduation: Joint PhD of SUSTech and Pengcheng Lab
Zhuoyu Yu
余卓宇
Graduated in 2024 with a bachelor's degree
After graduation: Research Assistant
Zhaoting Geng
耿兆珽
Graduated in 2024 with a bachelor's degree
After graduation: PhD in Hong Kong University
Pengzhuo Wu
吴鹏焯
Graduated in 2024 with a master's degree
After graduation: BYD Company
