News
[2026/3/17] Our paper was published in ACS Photonics (Supplementary Cover)
We demonstrate the first backward SBS in tantalum pentoxide (Ta2O5) waveguides, revealing a Brillouin gain of 4.9 m^–1 W^–1 at Brillouin frequency shift of 11.23 GHz. The strong nonlinear refractive index of 7.8×10^–19 m^2/W supports efficient supercontinuum generation (SCG) and four-wave mixing (FWM) in dispersion-engineered strip and rib waveguides across both anomalous and normal dispersion regimes. In the anomalous dispersion regime, SCG exceeding 300 nm is realized and theoretically extendable to over 1100 nm. FWM experiments exhibit a conversion efficiency of −48.1 dB and a potential bandwidth of 120 nm. In the normal dispersion regime, a flat supercontinuum spanning over 180 nm with power fluctuations below 15 dB is generated, serving as a broadband source for acetylene gas spectroscopy. These results highlight its exceptional versatility for multifunctional integrated nonlinear photonics.
The paper can be accessed on the ACS Photonics website.
[2026/3/6] Our paper was published in Advanced Photonics Research (Cover Feature)
The four-wave mixing conversion efficiencies of both the waveguides and the microresonators exhibit a well-correlated relation versus their effective lengths, confirming the unified theoretical framework. These experimentally validated findings offer a fresh perspective on Kerr nonlinearity and pave the way toward advancing the development of highly efficient nonlinear photonic devices and products. In this work, we propose a different perspective that FE can be interpreted as an elongation of effective length. Moreover, we establish a unified framework that bridges nonresonant waveguides and resonant cavities through this generalized effective length concept. We validate the model experimentally using direct-bonded gallium phosphide-on-insulator waveguides and microresonators.
This paper can be accessed on the Advanced Photonics Research website.
[2026/01/06] Dr. Zhao received Excellence Teaching Award
Dr. Zhao won the Excellence Teaching Award in the 2025 SUSTech teaching competition.
This news can be found here.
[2025/11/19] Our paper was published in Nature Communications
Here, we explore gallium phosphide (GaP) for supercontinuum generation, leveraging its strong second-order and Kerr nonlinearities, broad optical transparency, and low two-photon absorption at telecom C-band. We report the octave-spanning supercontinuum generation in a sub-millimeter GaP waveguide. The generated supercontinuum, when excited with transversely magnetically polarized light, features a gap-free spectrum and high coherence. Furthermore, our GaP waveguide demonstrates a figure of merit of 43.56 THz/mm/kW, which is the highest reported figure of merit among various integrated photonic platforms operating in the normal dispersion regime. We also observe and analyze the rich underlying physical mechanisms of multiple second harmonics. These results highlight the exceptional versatility of the GaP-on-isolator platform for broadband nonlinear photonics.
The paper can be accessed on the Nature Communications website.
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.
Integrated Lasers
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
12441004@mail.sustech.edu.cn
Mingjian You
游铭坚
PhD
12333354@mail.sustech.edu.cn
Ning Ding
丁宁
PhD
12333314@mail.sustech.edu.cn
Xingyu Tang
汤星宇
Master
12333287@mail.sustech.edu.cn
Junke Zhou
周峻珂
Master
12011712@mail.sustech.edu.cn
Qiwei Zheng
郑淇玮
Master
12532766@mail.sustech.edu.cn
Shengjie Liu
刘圣捷
Master
12532815@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
Shangyu Wang
王尚宇
Bachelor
12312621@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: Master of Philosophy in the Hong Kong Polytechnic University
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
Yihan Liu
刘逸涵
Graduated in 2025 with a bachelor's degree
After graduation: Master in SUSTech
Xiaolun Yu
余晓伦
Graduated in 2025 with a bachelor's degree
After graduation: Master in SUSTech
