A5050706950- Advanced Fiber Laser Technologies
- Laser-Matter Interactions and Applications
- Photonic Crystal and Fiber Optics
- Photonic and Optical Devices
- Advanced Fluorescence Microscopy Techniques
- Solid State Laser Technologies
- Advanced Fiber Optic Sensors
- Optical Coherence Tomography Applications
- Topological Materials and Phenomena
- Optical Network Technologies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Spectroscopy and Laser Applications
- Terahertz technology and applications
- Magnetic properties of thin films
- Advanced Frequency and Time Standards
- Nonlinear Photonic Systems
- Graphene research and applications
- Photorefractive and Nonlinear Optics
- Advanced Photonic Communication Systems
- Quantum and electron transport phenomena
- 2D Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Orbital Angular Momentum in Optics
- Advanced X-ray Imaging Techniques
Chinese Academy of Sciences
2018-2024
Shenyang Institute of Computing Technology (China)
2024
Czech Academy of Sciences, Institute of Physics
2020-2024
Center for Free-Electron Laser Science
2013-2024
Nanyang Technological University
2023-2024
Institute of Physics
2018-2023
University of Chinese Academy of Sciences
2019-2023
Songshan Lake Materials Laboratory
2021-2023
National Laboratory for Superconductivity
2018-2023
Universität Hamburg
2013-2020
X-ray crystallography is one of the main methods to determine atomic-resolution 3D images whole spectrum molecules ranging from small inorganic clusters large protein complexes consisting hundred-thousands atoms that constitute macromolecular machinery life. Life not static, and unravelling structure dynamics most important reactions in chemistry biology essential uncover their mechanism. Many these reactions, including photosynthesis which drives our biosphere, are light induced occur on...
We propose and demonstrate a new approach to implement wavelength-tunable ultrafast fiber laser source suitable for multiphoton microscopy. employ fiber-optic nonlinearities broaden narrowband optical spectrum generated by an Yb-fiber system then use bandpass filters select the leftmost or rightmost spectral lobes from broadened spectrum. Detailed numerical modeling shows that self-phase modulation dominates broadening, self-steepening tends blue shift spectrum, stimulated Raman scattering...
We investigate the dependence of Cherenkov radiation (CR) on pump pulse parameters and its evolution along propagation distance. Using a Ti:sapphire laser emitting 10fs pulses as source, we demonstrate highly efficient (>40%), broadband (>50nm) CR in visible-wavelength range with threshold energy less than 100pJ tuning over 100nm.
A new type of interaction between optical waves occurs in chirally-coupled-core (CCC) fibers. Instead linear-translational symmetry conventional cylindrical fibers, CCC fibers are helical-translation symmetric, and, consequently, fiber modes involves both spin and orbital angular momentum the waves. Experimentally this has been verified by observing a multitude phase-matching resonances transmitted super-continuum spectrum, theoretically explained through modal theory developed helical...
We demonstrate a fundamentally mode-locked Yb-fiber laser with 3 GHz repetition rate and ∼206 fs pulse duration. The incorporates two enabling technologies: 1 cm heavily Yb-doped phosphate glass fiber as the gain medium high-dispersion (-1300 fs2) output coupler to manage cavity dispersion. oscillator self-starts generates up 53 mW average power.
We demonstrate a pre-chirp managed Yb-doped fiber laser system that outputs 75 MHz, 130 W spectrally broadened pulses, which are compressed by diffraction-grating pair to 60 fs with average powers as high 100 W. Fine tuning the pulse chirp prior amplification leads high-quality pulses. Detailed experiments and numerical simulation reveal optimum group-delay dispersion increases from negative positive increasing output power for rod-type high-power amplifiers. The resulting parameters...
We deployed two wavelength calibrators based on laser frequency combs ("astro-combs") at an astronomical telescope.One astrocomb operated over a 100 nm band in the deep red (∼ 800 nm) and second 20 blue 400 nm).We used these astro-combs to calibrate high-resolution astrophysical spectrograph integrated with 1.5 m telescope, demonstrated calibration precision stability sufficient enable detection of changes stellar radial velocity < 1 m/s.
We demonstrate an energy scalable approach to implement ultrafast fiber laser sources suitable for deep tissue multi-photon microscopy imaging. Enabled by fiber-optic nonlinearities (dominated self-phase modulation), these unique produce nearly transform-limited pulses of 50-90 fs in duration with the center wavelength tunable range 1030-1215 nm. The resulting pulse can be scaled up 20 nJ optimizing dispersion, shortening length, and using large-mode-area fibers. applied such energetic...
We demonstrate that energetic femtosecond pulses tunable from 1.3 to 1.7 µm can be achieved using self-phase modulation enabled spectral broadening followed by lobe filtering. Based on a home-built 5-W Er-fiber laser system operating at 31-MHz repetition rate, we obtain continuously tuned with >4.5 nJ pulse energy. further optimize the process fiber larger mode area and scale up energy >10 nJ; resulting duration is as short ~50 fs. Such widely tunable, source well suited for driving scanning...
We demonstrate a self-starting 700 MHz repetition rate Yb:fiber laser incorporated with phase biased nonlinear amplifying loop mirror as an artificial saturable absorber.The delivers maximum power of 150 mW and pulse width 215 fs at pump 710 mW.The integration relative intensity noise (RIN) between 10 Hz results in minimum integrated RIN 0.015%.The the fundamental was also characterized different net-cavity dispersion.Although is made nonpolarization maintaining fiber, mode locking sustains...
Wavelength widely tunable femtosecond sources can be implemented by optically filtering the leftmost/rightmost spectral lobes of a broadened spectrum due to self-phase modulation (SPM) dominated fiber-optic nonlinearities. We numerically and experimentally investigate feasibility implementing such source inside optical fibers with negative group-velocity dispersion (GVD). show that broadening prior soliton fission is SPM generates well-isolated lobes; results in energetic pulses wavelength...
We demonstrate highly stable mode-locked Yb-doped fiber oscillators using a nonlinear amplifying loop mirror, delivering linearly polarized laser pulses with high energy at low repetition rate of several MHz. These lasers are composed polarization-maintaining fibers and fiber-based components without intra-cavity dispersion compensation. The spectral temporal characteristics systematically investigated different rates. Spectral bandwidth 31 nm is realized in the case 6 MHz rate, pulse...
A power-scalable approach for THz generation is demonstrated using optical rectification in GaP pumped by a high power ultrafast Yb-doped fiber amplifier operating at 1.055 mum. 120-MHz-repetition-rate pulse train of single-cycle radiation with 6.5 muW average generated 10 W from parabolic amplifier. Analysis the scalability indicates that due to unique advantages offered and lasers, this has potential generate trains powers up several mW.
We both theoretically and experimentally investigate the optimization of femtosecond Yb-doped fiber amplifiers (YDFAs) to achieve high-quality, high-power, compressed pulses. Ultrashort pulses amplified inside YDFAs are modeled by generalized nonlinear Schrödinger equation coupled steady-state propagation-rate equations. use this model study dependence compressed-pulse quality on YDFA parameters, such as gain fiber's doping concentration length, input pulse pre-chirp, duration, power. The...
Searches for Earth-like exoplanets using the periodic Doppler shift of stellar absorption lines require 10 cm/s precision in measurement radial velocity (RV) over timescales years. Current techniques have led to discovery short-period that induce RV wobbles as small ≈1 m/s on their parent stars. It has been suggested order-of-magnitude improved may be achievable an astro-comb, a laser frequency comb optimized astrophysical spectrograph wavelength calibration. Here we report development...
Transition metal dichalcogenides (TMDCs) with different thickness can greatly influence the performance of photonic devices. However, how to accurately control layers TMDCs and realize application in ultrafast photonics remains challenging. Here, we study dependence SnS2, which is one newly emerging TMDCs. The SnS2 crystals are synthesized by chemical vapor transport technique confirmed as n-type material first-principles calculations. As a potential application, samples three successfully...
We demonstrate high-power longwave mid-IR ultrafast sources based on a Er-fiber laser system at 1.55 µm with 32-MHz repetition rate. Compared previous 1.03-µm-driven difference frequency generation (DFG), our current configuration allows tighter focusing in the GaSe crystal thanks to an increased damage threshold µm. Consequently, 1.55-µm-driven DFG can operate regime of optical parametric amplification (OPA), which power grows exponentially respect square root pumping power. experimentally...
We demonstrate Chirally-Coupled-Core (CCC) fiber with 35-µm diameter and 0.07 NA core which is effectively single-mode. This a new type of fibers whose modal properties are defined both by their longitudinal transverse structure.
We demonstrate the generation of broadband THz pulses by optical rectification in GaP waveguides pumped high power Yb-doped fiber amplifiers. The dispersion emitter can be controlled via geometry waveguide; peak frequency emitted radiation is tuned varying waveguide cross-section. Most importantly, use a for emission increases coherent buildup length and offers scalability to higher power; this was investigated pumping with laser system. A 25-MHz-repetition-rate pulse train 120 muW average...
We demonstrate a tunable laser frequency comb operating near 420 nm with mode spacing of 20-50 GHz, usable bandwidth 15 and output power per line ~20 nW.Using the TRES spectrograph at Fred Lawrence Whipple Observatory, we characterize this system to an accuracy below 1m/s, suitable for calibrating high-resolution astrophysical spectrographs used, e.g., in exoplanet studies.
Fiber-optic Cherenkov radiation has emerged as a wavelength conversion technique to achieve isolated spectrum in the visible range.Most published results have reinforced impression that CR forms narrowband with poor efficiency.We both theoretically and experimentally investigate fiber-optic excited by fewcycle pulses.We introduce coherence length quantify Cherenkovradiation bandwidth its dependence on propagation distance.Detailed numerical simulations verified experimental reveal three...
We demonstrate a compact ultrafast source centered at 850 nm with >200 bandwidth (full width half-maximum) based on 3 GHz Yb-fiber master-oscillator-power-amplifier system. The output pulses (with up to 13 W average power) from the laser system are coupled into short (<50 mm) pieces of photonic crystal fibers excite broadband fiber-optic Cherenkov radiation; resulting broad phase-matching due fiber length produces an upconverted spectrum spanning in wavelength range 750-950 power 94, 184,...
A theoretical study of super generation in photonic crystal fiber and its application to pulse compression is presented. The evolution the spectrum can be divided into three stages: initial broadening below a certain threshold propagation distance, dramatic supercontinuum at and, finally, saturation spectral width on propagation. It found that group delay group-delay dispersion supercontinum are sensitive input peak power after further third stage. Fluctuations from amplified translated...