A5035719598- Terahertz technology and applications
- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Solid State Laser Technologies
- Gyrotron and Vacuum Electronics Research
- Particle Accelerators and Free-Electron Lasers
- Photonic and Optical Devices
- Spectroscopy and Laser Applications
- Laser Design and Applications
- Photorefractive and Nonlinear Optics
- Photonic Crystal and Fiber Optics
- Laser-Plasma Interactions and Diagnostics
- Superconducting and THz Device Technology
- Advanced X-ray Imaging Techniques
- Pulsed Power Technology Applications
- Advanced Electron Microscopy Techniques and Applications
- Magnetic properties of thin films
- Topological Materials and Phenomena
- Particle accelerators and beam dynamics
- Optical Network Technologies
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Crystallography and Radiation Phenomena
- Photonic Crystals and Applications
- Laser-induced spectroscopy and plasma
Deutsches Elektronen-Synchrotron DESY
2013-2023
Universität Hamburg
2013-2022
Center for Free-Electron Laser Science
2013-2022
Max Planck Institute for the Structure and Dynamics of Matter
2013-2021
Hamburg Centre for Ultrafast Imaging
2015-2021
Massachusetts Institute of Technology
2017-2018
Max Planck Society
2013-2014
Kaiser-Franz-Josef-Spital
2009
Highly-efficient optical generation of narrowband terahertz radiation enables unexplored technologies and sciences from compact electron acceleration to charge manipulation in solids. State-of-the-art conversion efficiencies are currently achieved using difference-frequency driven by temporal beating chirped pulses but remain, however, far lower than desired or predicted. Here we show that high-order spectral phase fundamentally limits the efficiency chirped-pulse resolve this limitation...
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...
Ultrashort electron beams with narrow energy spread, high charge, and low jitter are essential for resolving phase transitions in metals, semiconductors, molecular crystals. These semirelativistic beams, produced by phototriggered guns, also injected into accelerators x-ray light sources. The achievable resolution of these time-resolved diffraction or experiments has been hindered surface field timing limitations conventional RF which thus far <200 MV/m >96 fs, respectively. A gun driven...
A cryogenic composite-thin-disk amplifier with amplified spontaneous emission (ASE) rejection is implemented that overcomes traditional laser system problems in high-energy pulsed drivers of high average power. small signal gain 8 dB was compared to a 1.5 for an uncapped thin-disk without ASE mitigation under identical pumping conditions. strict image relayed 12-pass architecture using off-axis vacuum telescope and polarization switching extracted 100 mJ at 250 Hz beam quality stretched 700...
Terahertz (THz)-based electron acceleration and manipulation has recently been shown to be feasible hold tremendous promise as a technology for the development of next-generation, compact sources. Previous work concentrated on structures powered transversely by short, single-cycle THz pulses, with mm-scale, segmented interaction regions that are ideal electrons in sub- few-MeV range where velocities vary significantly. However, order extend this multi-MeV range, investigation approaches...
Terahertz-based electron acceleration has recently emerged as a promising candidate for driving next-generation high-brightness sources. Although initial demonstrations have proven the feasibility of this technology accelerating and manipulating phase space electrons, further exquisite timing control are required to make use terahertz demanding applications such light sources ultrafast diffraction. In paper, we two-stage segmented-terahertz-electron-accelerator-and-manipulator (STEAM) setup...
We generate white light supercontinuum from slightly sub-picosecond pulses at 1.03 µm and 515 nm. compare the spectra stability for various crystals, focusing conditions pulse durations, determine best parameters driver duration. Comparing experimental observations with theory of white-light generation Brodeur Chin, it appears that in this particular range pump duration, two mechanisms interact prevent a catastrophic collapse beam: multi-photon excitation (typical ~100-fs-long pulses)...
A highly stable Yb:KYW based dual crystal regenerative amplifier is demonstrated, which generates at 1 kHz 6.5-mJ pulses before and up to 4.7-mJ sub-ps after compression with multilayer-dielectric gratings, respectively. The stretcher compact on chirped-fiber Bragg gratings. In continuous-wave operation, 20 W are extracted a slope efficiency of 40%. experimental data in agreement detailed simulations the laser dynamics.
We demonstrate a Ho:YLF regenerative amplifier (RA) overcoming bifurcation instability and consequently achieving high extraction energies of 6.9 mJ at repetition rate 1 kHz with pulse-to-pulse fluctuations 1.1%. Measurements the output pulse energy, corroborated by numerical simulations, identify an operation point (OP) that allows high-energy minimum noise level. Complete suppression onset was achieved gain saturation after each pumping cycle in crystal via lowering cooling crystal. Even...
We report on a diode-pumped, hybrid Yb-doped chirped-pulse amplification (CPA) laser system with compact pulse stretcher and compressor, consisting of fiber preamplifiers, room-temperature Yb:KYW regenerative amplifier (RGA), cryogenic Yb:YAG multi-pass amplifiers. The RGA provides relatively broad bandwidth thereby long duration to mitigate B-integral in the CPA chain. ~1030-nm pulses are amplified up 70 mJ at 1-kHz repetition rate, currently limited by available optics apertures, then...
We systematically study the efficiency enhancement of high-harmonic generation (HHG) in an Ar gas cell up to soft X-ray (SXR) range using a two-color laser field composed 2.1 μm (ω) and 700 nm (3ω) with parallel linear polarization. Our experiment follows recent theoretical investigations that determined mid-infrared (IR) pulses, mixed their third harmonic (ω + 3ω), be close optimal driving waveforms for enhancing HHG SXR region [Jin et al., Nature Comm. 5, 4003 (2014)]. observed...
Terahertz- (THz-) based electron manipulation has recently been shown to hold tremendous promise as a technology for manipulating and driving the next generation of compact ultrafast sources. Here, we demonstrate an diffractometer with THz-driven pulse compression. The bunches from conventional DC gun are compressed by factor 10 reach duration ~180 fs (FWHM) 10,000 electrons/pulse at 1 kHz repetition rate. resulting source is used in proof-of-principle experiment probe photoinduced dynamics...
We report on a high power diode-pumped laser using multiple bulk Yb:KY(WO(4))(2) (KYW) crystals in resonator optimised for this operation. From dual-crystal we obtain more than 24 W of cw-power TEM(00) mode limited by the available pump power. also present results semiconductor saturable absorber mirror (SESAM) mode-locking soliton as well positive dispersion regime with average output powers 14.6 and 17 respectively.
This paper reports on a high-power dual-crystal Yb:CALGO laser head with greatly reduced sensitivity to thermal lensing in the gain medium. In continuous-wave operation 23 W of power were extracted from 2% doped crystals, and tunablity between 1018 nm 1060 was demonstrated. is highest output reported bulk date, as well demonstration broadest tuning range. 4 mJ pulses at 1040 achieved cavity-dumped quasi-CW pumping 1 kHz repetition rate nearly diffraction-limited beam quality. When seeded...
We demonstrate experimentally for the first time a ~40-µJ two-octave-wide passively carrier-envelope phase (CEP)-stable parametric front-end seeding an ytterbium (Yb)-pump-based, few-optical-cycle, high-energy optical waveform synthesizer. The system includes CEP-stable white-light continuum and two-channel chirped pulse amplifiers (OPCPAs) in near- mid-infrared spectral regions spanning altogether spectrum driven by regenerative amplifier. output pulses are compressed fully characterized to...
We investigate a regime of parametric amplification in which the pump and signal waves are spectrally separated by only few hundreds GHz frequency - therefore resulting sub-THz idler wave. Operating this we find an optical amplifier (OPA) behavior is highly dissimilar to conventional OPAs. In regime, observe multiple three-wave mixing processes occurring simultaneously results spectral cascading around Via numerical simulations, elucidate at work show that cascaded offers pathway toward...
We present results on the development of a cryogenic Yb:YAG multi-pass laser amplifier based composite thin-disk design and demonstrate one-joule, diffraction limited, chirped 234-ps pulses with 50% optical-to-optical efficiency. High beam quality was obtained for repetition rates up to 400 Hz. The hardware disassembled thoroughly inspected after accumulating 80 hours use at from 100 500 Hz exhibited no signs damage. This driver is now commissioned dedicated laboratory where grating...
We report on efficient broadband sum-frequency generation, converting a 140 THz near-infrared bandwidth to the visible regime with photon conversion efficiency greater than 90%. Using 20-mm-long aperiodically adiabatively poled KTP crystal, spectral range 660-990 nm was converted 405-500 using strong pump wave at 1030 nm. The confirmed be 92±0.5% when pumped an intensity of 0.94 GW/cm2. Our experimental results agreed very well analytic predictions and numerical simulations.
We present possible conceptual designs of a laser system for driving table-top free-electron lasers based on terahertz acceleration. After discussing the achievable performances amplifiers with Yb:YAG at cryogenic and room temperature Yb:YLF temperature, we amplification modules available results concepts amplifier chains these media. Their are discussed in light specifications tasks within source. Technical engineering challenges, such as cooling, control, synchronization diagnostics,...
The generation of high-energy narrowband terahertz radiation has gained heightened importance in recent years due to its potentially transformative impact on spectroscopy, high-resolution radar and more recently electron acceleration. Among various applications, such is particularly important for table-top free lasers, which are at the moment a subject extensive research. Second-order nonlinear optical methods among most promising techniques achieve required coherent with energy > 10 mJ,...
We demonstrate multi-cycle terahertz (MC-THz) generation in a 15.5 mm long periodically poled rubidium (Rb)-doped potassium titanyl phosphate (Rb:PPKTP) crystal with poling period of 300 µm. By cryogenically cooling the to 77 K, up 0.72 µJ energy is obtained at frequency 0.5 THz 3 GHz bandwidth. A maximum internal optical-to-terahertz conversion efficiency 0.16% achieved, which comparable results achieved using lithium niobate crystal. Neither photorefractive effects nor damage was observed...
We demonstrate the generation of 100 GHz single-cycle pulses with up to 10 MW peak power using optical rectification and broadband phase matching via tilted pulse front (TPF) technique in lithium niobate. The driver is a cryogenically cooled Yb:YAG amplifier providing tens mJ energy, ~5 ps long laser pulses. obtain high THz energy 65 µJ 31.6 MV/m electric field when focused close its diffraction limit 2.5 mm diameter. A optical-to-THz conversion efficiency 0.3% at 85 K measured agreement...
We describe initial steps in the development of technology for a THz-driven accelerator that will drive compact attosecond X-ray light source. structures represent promising emerging acceleration sub-femtosecond electron bunches. The millimeter scale driving field offers favorable compromise between conventional accelerators which are proven and reliable but large costly, other advanced like plasma-based or laser-driven devices where microscopic make device control difficult limit charge...
We report a high power/high energy dual-crystal Yb:KYW regenerative amplifier using single chirped volume Bragg grating (CVBG) as stretcher/compressor with more than 12W average power at repetition-rates >40kHz and compressed pulsewidths around 500fs.