A5041695316- Advanced Fiber Laser Technologies
- Photonic Crystal and Fiber Optics
- Laser-Matter Interactions and Applications
- Photonic and Optical Devices
- Advanced Fiber Optic Sensors
- Diamond and Carbon-based Materials Research
- Optical Network Technologies
- 2D Materials and Applications
- Terahertz technology and applications
- Solid State Laser Technologies
- Mechanical and Optical Resonators
- Spectroscopy and Laser Applications
- Plasmonic and Surface Plasmon Research
- Photonic Crystals and Applications
- Nonlinear Photonic Systems
- Photorefractive and Nonlinear Optics
- Nonlinear Waves and Solitons
- Acoustic Wave Resonator Technologies
- Near-Field Optical Microscopy
- Advanced Chemical Physics Studies
- Advanced Mathematical Physics Problems
- Superconducting and THz Device Technology
- Semiconductor Lasers and Optical Devices
- Perovskite Materials and Applications
- Nonlinear Optical Materials Studies
Technical University of Denmark
2019-2025
Ørsted (Denmark)
2020-2023
ZHAW Zurich University of Applied Sciences
2020
Imperial College London
2010-2020
University of British Columbia
2017-2020
University of Brescia
2017
University of Konstanz
2016
Imperial Valley College
2010
Abstract Black phosphorus is a two-dimensional material of great interest, in part because its high carrier mobility and thickness dependent direct bandgap. However, instability under ambient conditions limits deposition options for device fabrication. Here we show black ink that can be reliably inkjet printed, enabling scalable development optoelectronic photonic devices. Our binder-free suppresses coffee ring formation through induced recirculating Marangoni flow, supports excellent...
We report an ultrafast laser mode-locked with a graphene saturable absorber. The linear dispersions of the Dirac electrons in enable wideband tunability. get ∼1 ps pulses, tunable between 1525 and 1559 nm, stable mode-locking, insensitive to environmental perturbations.
We fabricate a few-layer molybdenum disulfide (MoS₂) polymer composite saturable absorber by liquid-phase exfoliation, and use this to passively Q-switch an ytterbium-doped fiber laser, tunable from 1030 1070 nm. Self-starting Q-switching generates 2.88 μs pulses at 74 kHz repetition rate, with over 100 nJ pulse energy. propose mechanism, based on edge states within the bandgap, responsible for wideband nonlinear optical absorption exhibited our MoS₂ sample, despite operating photon energies...
We demonstrate mode-locking of a thulium-doped fiber laser operating at 1.94µm, using graphene-based saturable absorber.The outputs 3.6ps pulses, with∼0.4nJenergy and an amplitude fluctuation∼ 0.5%, 6.46MHz.This is simple, low-cost, stable convenient oscillator for applications where eye-safe low-photon-energy light sources are required, such as sensing biomedical diagnostics.
Abstract We fabricate a free-standing few-layer molybdenum disulfide (MoS 2 )-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1,535 nm 1,565 nm, are generated, corresponding photon energies below the MoS material bandgap. These results contribute growing body work studying nonlinear optical properties transition metal dichalcogenides that...
We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm 1924 respectively. Such operating wavelengths correspond sub-bandgap absorption in MoSe2, which explained the...
Two-dimensional (2D) nanomaterials are an emergent and promising platform for future photonic optoelectronic applications. Here, we review recent progress demonstrating the application of 2D as versatile, wideband saturable absorbers Q-switching mode-locking fibre lasers. We focus specifically on family few-layer transition metal dichalcogenides, including MoS2, MoSe2 WS2.
Few-layer molybdenum disulfide (MoS2) is emerging as a promising quasi-two-dimensional material for photonics and optoelectronics, further extending the library of suitable layered nanomaterials with exceptional optical properties use in saturable absorber devices that enable short-pulse generation laser systems. In this work, we catalog review nonlinear few-layer MoS2, summarize recent progress processing integration into devices, comment on current status future perspectives MoS2-based...
We report second- and third-harmonic generation in monolayer MoS2 as a tool for imaging accurately characterizing the material's nonlinear optical properties under 1560 nm excitation. Using surface optics treatment, we derive expressions relating experimental measurements to third-order sheet susceptibility magnitudes, obtaining values of m2 V−1 and, first time MoS2, m3 V−2. These susceptibilities correspond effective bulk m V−2, accounting thickness. Experimental comparisons between...
We demonstrate that mode-locking of ytterbium fiber lasers with a carbon nanotube saturable absorber can produce pulses ranging from 20 ps to 2 ns at repetition rates between 21 MHz and 177 kHz, respectively, depending on cavity length. Nonlinear polarization evolution is not responsible for mode-locking. Even in the nanosecond regime, clean single are observed pulse train exhibits low jitter. Combined extremely large chirp, these properties suited chirped-pulse amplification systems.
Abstract Instabilities are common phenomena frequently observed in nature, sometimes leading to unexpected catastrophes and disasters seemingly normal conditions. One prominent form of instability a distributed system is its response harmonic modulation. Such has special names various branches physics generally known as modulation (MI). The MI leads growth-decay cycle unstable waves therefore related Fermi-Pasta-Ulam (FPU) recurrence since breather solutions the nonlinear Schrödinger...
A binary solvent ink exploiting solutal Marangoni flows to suppress the coffee-ring effect for uniform printing of 2D crystals.
Abstract Short-pulse fibre lasers are a complex dynamical system possessing broad space of operating states that can be accessed through control cavity parameters. Determination target regimes is multi-parameter global optimisation problem. Here, we report the implementation genetic algorithm to intelligently locate optimum parameters for stable single-pulse mode- locking in Figure-8 laser, and fully automate turn-on procedure. Stable ultrashort pulses repeatably achieved by employing...
Increasing the average power of broadband, few-cycle terahertz (THz) sources is currently a topic intense investigation, fueled by recent immense progress in high femtosecond laser driving at 1030 nm. However, many crucial applications would benefit not only from an increase power, but also ultra-broad bandwidth, while maintaining dynamic range these frequencies. This calls for challenging combination repetition rates and simultaneously. Here, we discuss promising approach enabled organic...
We evaluate the shape and chirp of nanosecond pulses from a fiber laser passively mode locked with nanotube-based saturable absorber by using synchronously scanning streak camera monochromator to directly measure pulse spectrogram. show that stable sech2 output possesses predominantly linear chirp, residual quartic phase low noise. Comparison analytical mode-locking theory shows good quantitative agreement master equation model.
We demonstrate a mid-infrared Raman-soliton continuum extending from 1.9 to 3 µm in highly germanium-doped silica-clad fiber, pumped by nanotube mode-locked thulium-doped fiber system, delivering 12 kW sub-picosecond pulses at 1.95 µm.This simple and robust source of light covers portion the atmospheric transmission window.
We demonstrate wide-band ultrafast optical pulse generation at 1, 1.5, and 2 μm using a single-polymer composite saturable absorber based on double-wall carbon nanotubes (DWNTs). The freestanding quality polymer is prepared from dispersed in water with poly(vinyl alcohol) as the host matrix. then integrated into ytterbium-, erbium-, thulium-doped fiber laser cavities. Using this single DWNT-polymer composite, we achieve 4.85 ps, 532 fs, 1.6 ps mode-locked pulses 1066, 1559, 1883 nm,...
We demonstrate passive mode-locking of a Bi-doped fiber laser using nanotube-based saturable absorber. achieve stable in both the all-normal and net anomalous dispersion regimes. Near transform-limited 4.7 ps soliton pulses are generated average-soliton regime, with chirped Bragg grating used for compensation to retain an all-fiber format.
We characterize the saturable absorption of second (E22) electronic transition a sample single-walled carbon nanotubes and use it to mode-lock an ytterbium fiber ring laser. The modulation depth ∼ 15% was found be similar corresponding E11 (∼ 13%), but saturation intensity 220 MW cm-2) about order magnitude larger 10 cm-2). achieved 15 MHz mode-locked pulse train with output duration 6.5 ps. For comparison we also demonstrate stable mode-locking on transition, same nanotubes, erbium laser,...
We present the synchronization of two all-fiber mode-locked lasers, operating at 1.0 μm and 1.54 μm, coupled through use a shared single-wall carbon nanotube absorber. Both lasers operate in soliton-regime, achieving synchronized repetition rate 13.08 MHz. The broadband absorption range nanotubes allows stable mode-locking behavior 1 1.5 μm. nonlinear coupling effects between energy states absorber result pulses for hours operation, with large cavity mismatch 1400
Unlocking the true potential of optical spectroscopy on nanoscale requires development stable and low-noise laser sources. Here, we have developed a supercontinuum (SC) source based an all-normal dispersion fiber pumped by femtosecond demonstrate high resolution, spectrally resolved near-field measurements in near-infrared (NIR) region. Specifically, explore reduced-noise requirements for aperture-less scattering-type scanning microscopy (s-SNOM), including inherent pulse-to-pulse...
We demonstrate passive mode-locking of a Raman fiber laser using nanotube-based saturable absorber coupled to net normal dispersion cavity. This generates highly chirped 500 ps pulses. These are then compressed down 2 ps, with 1.4 kW peak power, making it simple wavelength-versatile source for various applications.
Ultrafast terahertz (THz) spectroscopy is a potent tool for studying the fundamental properties of matter. Limitations current THz sources, however, preclude technique being applied in certain advanced configurations or measurement of, e.g., strongly absorbing samples. In response to this problem, here we demonstrate generation 1.38 mW broadband radiation at 10 MHz repetition rate by combining highly efficient nonlinear organic crystal HMQ-TMS with ultrafast pump pulses generated using...
We develop an analytical model to describe sub-bandgap optical absorption in two-dimensional semiconducting transition metal dichalcogenide (s-TMD) nanoflakes. The material system represents array of few-layer molybdenum disulfide crystals, randomly orientated a polymer matrix. propose that involves direct transitions between electronic edge-states and bulk-bands, depends strongly on the carrier population, is saturable with sufficient fluence. For excitation energies above half bandgap,...
We report the experimental observation of scalar and cross-phase modulation instabilities by pumping a highly birefringent photonic crystal fiber in normal dispersion regime at 45° to its principal polarization axes. Five sideband pairs (two three vector ones) are observed simultaneously spontaneous regime, four which have large frequency shift from pump, range 79-93 THz. These results excellent agreement with phase-matching arguments numerical simulations.