School of Information Engineering · Sanming University

Making different colors
of light beat in step. Passive synchronization of ultrafast fiber lasers

We establish femtosecond-level timing lock across 1 μm, 1.55 μm and 1.9 μm — and study how solitons pull, capture and lose each other inside coupled cavities.

The Ultrafast Photonics Lab belongs to the School of Information Engineering at Sanming University and is affiliated with the Fujian Key Laboratory of Agricultural IoT Application. Our work runs the full chain from devices (saturable absorbers) to mechanisms (nonlinear dynamics) to sources (mid-infrared femtosecond lasers).

All three share one carbon-nanotube saturable absorber Timing offset < ±2–3 ps
13+
Selected SCI papers
first / corresponding author
3λ
1 / 1.55 / 1.9 μm
synchronized mode-locking
±2–3ps
timing capture window
experimental tolerance
fs-level
integrated timing jitter
in the locked state
01 Research

Four threads, one chain From materials → nonlinear mechanisms → laser systems → intelligent control

The performance ceiling of an ultrafast fiber laser is set by the bandwidth of its saturable absorber, the balance of intracavity nonlinearity and dispersion, and the timing coupling between multiple pulse trains. We work along that chain — moving from "getting light out" to "getting light out controllably".

R1 / Multicolor synchronization

Passive synchronization of multicolor ultrafast fiber lasers Passive synchronization

A single double-walled carbon nanotube (DWCNT) saturable absorber mode-locks three cavities at 1 μm, 1.55 μm and 1.9 μm over a bandwidth exceeding 900 nm — and locks them to each other in time. We map how the capture range depends on common-arm length and pump ratio; experiments show the in-phase capture window peaks at a common arm of about 6 m.

DWCNT Three-color cavity XPM ±2–3 ps capture
R2 / Nonlinear dynamics

Synchronization dynamics and soliton molecules Nonlinear dynamics

Pulse timings reduce to a circle map with two competing coupling channels: an attractive force from total-intensity bleaching of the shared absorber, and a repulsive force from cross-phase-modulation-induced frequency shifts. The full phase diagram in the pump-ratio–cavity-mismatch plane is classified by largest Lyapunov exponent and winding number into phase locking, quasi-periodic slipping, chaotic timing dynamics and free-running unlocking.

Circle map Lyapunov exponent Arnold tongues Soliton molecules
R3 / Materials & devices

Novel saturable absorbers Saturable absorbers

Conventional SESAMs are narrowband and degrade irreversibly above roughly 1–2 W of intracavity average power. We study the nonlinear optical response and fabrication of DWCNTs, MoS₂ and related low-dimensional materials, balancing modulation depth, response time, damage threshold and long-term stability.

DWCNT MoS₂ SESAM Broadband ML
R4 / Sources & applications

Mid-IR high-energy pulses and intelligent lasers Mid-IR & intelligent lasers

Self-mode-locking combined with dispersion management delivers high-energy pulses from a 2 μm Tm-doped fiber laser, while a CNT-NALM hybrid structure improves robustness against pump fluctuation and loss perturbation. In parallel, we combine deep learning with physical models to control the polarization state of a mode-locked laser — letting the laser find its own stable operating point.

Tm-doped NALM Mamyshev Intelligent control
02 Publications

Selected publications 2021 – 2026

More than ten SCI papers as first or corresponding author, in journals including Nanophotonics, Optics Letters, Chaos, Solitons & Fractals, and Journal of Lightwave Technology.

13 papers
2026

Competing couplings drive four synchronization regimes in a three-color all-fiber soliton laser

Chaos, Solitons & Fractals · Sanming University as first affiliation First author

Featured
2026

Recent Advances in MoS₂-Based Saturable Absorbers for Mode-Locked Fiber Lasers

Nanomaterials 16(15) 911 · undergraduate Jiahao Huang as first author Corresponding

Review
2026

Numerical Investigation of Transient Mode-Locking Dynamics in a SESAM-Based Yb-Doped Picosecond Fiber Laser

Photonics 13(7) 651 Co-author

2025

Coherent Phonon Dynamics in 2D van der Waals Semiconductors

Low-Dimensional Materials 1(1) 2 · review Co-corresponding

2024

Generation of high-energy self-mode-locked pulses in a Tm-doped fiber laser

Applied Physics Letters First author

2024

Influence of anisotropic factor fluctuations on the scintillation index in optical turbulence

Journal of the Optical Society of America A Co-author

2023

Synchronized triple-wavelength fiber lasers at 1, 1.55, and 1.9 μm

Optics Letters First author

Highlight
2022

72-fs Er-doped Mamyshev Oscillator

Journal of Lightwave Technology 40(7) 2123 · 50+ citations First author

Most cited
2022

Low mode-locking threshold and sub-90 fs Er-doped Mamyshev oscillator

Optics Communications 508 127711 First author

03 People

Our team Principal investigator & group

Jiancheng Zheng

Jiancheng Zheng 郑建城

PhD · Associate Professor · Master's supervisor · Head, Department of IoT Engineering

Dr. Zheng received his B.Eng. in Electrical Engineering and Automation from Wuhan University in 2015, and his PhD from the College of Electronic and Information Engineering at Nanjing University of Aeronautics and Astronautics. He was a CSC-funded visiting PhD student at Aalto University, Finland (Prof. Zhipei Sun's group, QTF Centre of Excellence). His research covers laser technology, ultrafast photonics and intelligent lasers.

Email jczheng@fjsmu.edu.cn ORCID 0000-0001-9680-8183 Address Sanming, Fujian 365004, China

Group composition

Jiancheng Zheng PI · Associate Professor
Master's students Electronic Information · Optoelectronic Engineering
Undergraduate researchers Optoelectronics / IoT Engineering
Collaborating faculty Prof. Chibiao Liu et al.
Active grants NSFC 62605243 / 62505160 · Fujian 2024J08081

The group is affiliated with the Fujian Key Laboratory of Agricultural IoT Application and maintains long-term collaborations with the QTF Centre of Excellence at Aalto University, Tel Aviv University, Zhejiang University and Zhejiang Normal University.

Collaborating faculty

Cross-group collaboration in laser propagation, optical information devices, intelligent algorithms and materials

Chibiao Liu
Chibiao Liu 刘持标
Professor · Dean, School of Information Engineering

Holds PhDs in computer science and physical chemistry; Fujian Class-C senior talent. Works on IoT, blockchain and AI, with 9 national/provincial projects, 16 patents and 15 software copyrights.

Jinyu Xie
Jinyu Xie 谢锦宇
PhD · Head, Department of Computer Science

Studies laser propagation through turbulent media and multimode optical field interpretation; awarded a 2025 NSFC Young Scientists Fund grant.

Xianmiao Xu
Xianmiao Xu 徐贤淼
PhD · Director, Experimental Teaching Centre

PhD in optical engineering from Fujian Normal University. Works on polarization holography, optical data storage and imaging metrology; 10+ SCI papers and five national key R&D sub-projects.

Heming Jia
Heming Jia 贾鹤鸣
Professor · Associate Dean

Listed among the world's top 2% scientists and China's top 1% highly cited researchers (2025); supports the group in intelligent optimisation and laser state prediction.

Yufeng Chi
Yufeng Chi 池毓锋
Associate Professor

Works at the interface of atmospheric environment governance and AI, with a 2026 single-institution paper in Journal of Cleaner Production and a first-author paper in Ecological Indicators.

External network Partners
Long-term collaborations

QTF Centre of Excellence (Aalto University, Finland), Tel Aviv University, Zhejiang University and Zhejiang Normal University — covering device fabrication, field-level simulation and experimental validation.

Dr. Jiancheng Zheng presenting on passively synchronized ultrafast fiber lasers
Nov 2025 Dr. Zheng speaking at the Frontiers in AI and Optoelectronic Technology symposium on "Passively Synchronized Ultrafast Fiber Lasers". Photo: School of Information Engineering, Sanming University.
04 News

News & highlights Recent activity

2026.11.13
Paper

Three-color soliton synchronization study published in Chaos, Solitons & Fractals

With Sanming University as the first affiliation, the paper introduces a "competing couplings" picture of four synchronization regimes and provides design rules for multimodal nonlinear imaging sources.

First page of the paper: Competing couplings drive four synchronization regimes in a three-color all-fiber soliton laser
Chaos, Solitons & Fractals 213 (2026) 119329 · first author Jiancheng Zheng
2026.09.16
Platform

Sanming University approved for a professional master's programme in Electronic Information

The new degree programme covers computer technology, artificial intelligence and optoelectronic information engineering. The group now admits master's students in the last of these.

2026.07.24
Paper

Undergraduate-first-author review on MoS₂ saturable absorbers published in Nanomaterials

Jiahao Huang is first author; the review surveys nonlinear optical properties, fabrication strategies and mode-locking applications of two-dimensional MoS₂.

2026.04.15
Teaching

Department workshop on curriculum-based ideological education and digital teaching

Dr. Zheng shared strategies for integrating explicit and implicit threads of ideological education into IoT engineering courses.

2025.11.07
Talk

Frontier seminar on artificial intelligence and optoelectronic technology

Dr. Zheng presented "Passive synchronization of ultrafast fiber lasers: mechanisms, implementation and applications", covering multicolor passive synchronization via cross-phase modulation and DWCNT saturable absorbers.

05 Facilities

Facilities and methods Platform & technical route

The lab supports the full cycle of fiber laser work — cavity design, fiber splicing, loss measurement, pulse characterization and numerical modelling.

Experimental capability Experiment

  • All-fiber cavity design and construction (ring / figure-8 / NALM / Mamyshev)
  • Fiber splicing and intracavity loss measurement
  • Dispersion management: DCF, grating pairs, chirped FBGs
  • Pulse characterization: spectrum, autocorrelation, RF spectrum, real-time trace
  • Multi-channel timing synchronization and jitter measurement

Materials & devices Materials

  • Carbon-nanotube (SWCNT / DWCNT) saturable absorbers
  • 2D materials (MoS₂ and related transition-metal dichalcogenides)
  • SESAM semiconductor saturable absorber mirrors
  • Nonlinear amplifying loop mirror as artificial SA
  • Film transfer, Raman and absorption spectroscopy

Numerical modelling Simulation

  • Field-level coupled generalized NLSE (CGNLSE) models
  • Coupled cavities with group-velocity walk-off and a shared absorber
  • Circle-map reduction, Lyapunov exponent and winding number analysis
  • Wavelet analysis of slip velocity for regime discrimination
  • Deep-learning-assisted laser state prediction and control
06 Join Us

Join us Open positions & collaboration

We welcome students and collaborators interested in ultrafast optics, nonlinear dynamics and intelligent lasers. You do not need to know how to build a laser on day one — but you should be willing to get your hands dirty and to chase a phenomenon to the end.

Master's students Open

We admit professional master's students through the Electronic Information programme (optoelectronic information engineering track) at Sanming University.

  • Topics: ultrafast fiber lasers, nonlinear dynamics, intelligent lasers
  • Background: optics, electronics, physics or computer science; programming or hands-on lab skills preferred
  • Support: open access to lab equipment, guidance toward SCI publications and patents

Undergraduate research

The group regularly supervises national and provincial undergraduate innovation projects and student competitions. Several undergraduates have published as first authors.

  • Possible work: fiber laser construction, numerical simulation, material fabrication and characterization
  • Opportunities: innovation training programmes, Challenge Cup, China International Innovation Competition
  • Rhythm: group meetings several times a month, progressing from literature to hands-on work

Collaboration

We are open to joint research, joint proposals and sample testing in ultrafast sources, nonlinear optics, fiber devices and intelligent control.

  • Academic: co-authored papers, joint grant applications
  • Industrial: ultrafast laser prototyping, technical consulting
  • Training: joint student supervision with domestic and overseas groups

Visiting

The lab is located at Sanming University, Sanming, Fujian. Please contact us by email before visiting.

  • Address: School of Information Engineering, Sanming University, Sanming 365004, China
  • Affiliation: Fujian Key Laboratory of Agricultural IoT Application
  • Please confirm time and discussion topic one week in advance

Send your CV and a short statement of research interests to

jczheng@fjsmu.edu.cn