A5016179719- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Particle Accelerators and Free-Electron Lasers
- Advanced X-ray Imaging Techniques
- Solid State Laser Technologies
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Laser Design and Applications
- Mass Spectrometry Techniques and Applications
- Photocathodes and Microchannel Plates
- Gyrotron and Vacuum Electronics Research
- Photorefractive and Nonlinear Optics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Laser Material Processing Techniques
- Crystallography and Radiation Phenomena
- Advanced Electron Microscopy Techniques and Applications
- Terahertz technology and applications
- Spectroscopy and Laser Applications
- Spectroscopy and Quantum Chemical Studies
- Semiconductor Quantum Structures and Devices
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Photonic Crystal and Fiber Optics
- Advanced Frequency and Time Standards
- Advancements in Photolithography Techniques
Paul Scherrer Institute
2014-2024
École Nationale Supérieure de Techniques Avancées
2006-2009
École Polytechnique
2006-2009
Centre National de la Recherche Scientifique
2006-2009
ParisTech
2009
Laboratoire d'Optique Appliquée
2006-2009
Amplitude Systèmes (France)
2009
École Normale Supérieure - PSL
2008
Université Jean Monnet
2005
The SwissFEL soft X-ray free-electron laser (FEL) beamline Athos will be ready for user operation in 2021. Its design includes a novel layout of alternating magnetic chicanes and short undulator segments. Together with the APPLE X architecture undulators, branch can operated different modes producing FEL beams unique characteristics ranging from attosecond pulse length to high-power modes. Further space has been reserved upgrades including modulators an external seeding better timing...
X-ray free-electron lasers (FELs) are state-of-the-art scientific tools capable to study matter on the scale of atomic processes. Since initial operation FELs more than a decade ago, several facilities with upgraded performance have been put in operation. Here we present first lasing results Athos, soft FEL beamline SwissFEL at Paul Scherrer Institute Switzerland. Athos features an undulator layout based short APPLE-X modules providing full polarisation control, interleaved small magnetic...
We report the generation of 4.3 fs, 1 mJ pulses at kHz using a hollow-core fiber compressor seeded with circularly polarized laser pulses. observe up to 30% more energy throughput compared case linearly input, together significantly improved output spectral stability. Seeding proves be an effective approach for high-energy operation hollow-fiber compression technique.
The SwissFEL Injector Test Facility operated at the Paul Scherrer Institute between 2010 and 2014, serving as a pilot plant testbed for development realization of SwissFEL, X-ray Free-Electron Laser facility under construction same institute. test consisted laser-driven rf electron gun followed by an S-band booster linac, magnetic bunch compression chicane diagnostic section including transverse deflecting cavity. It delivered bunches up to 200 pC charge 250 MeV beam energy repetition rate...
Electron beams in modern linear accelerators are now becoming limited brightness by the intrinsic emittance of photocathode electron source. Therefore it becomes important for large scale facilities such as free lasers to reduce this fundamental limit. In Letter we present measurements different laser wavelength (from 261 282 nm) and materials Mo, Nb, Al, Cu. Values low $0.41\ifmmode\pm\else\textpm\fi{}0.03\text{ }\text{...
We generate frequency-tunable narrow-band intense fields in the terahertz (THz) range by optical rectification of a temporally modulated near-infrared laser pumping nonlinear organic crystal. Carrier-frequency tunability between 0.5 and 6.5 THz is achieved changing modulation period pump. This tunable source allows selective coherent excitation adjacent vibrational modes, which are demonstrated for two phonons with frequency offset 0.8 single-crystal SrCu2(BO3)2. Our compact scalable enables...
We demonstrate a versatile tunable and highly stable ultrabroadband Ti:sapphire chirped pulse amplification system with compressed energy of 20 mJ at 100 Hz repetition rate.High power Ti:Sa systems in principle do not offer wavelength tunability due to gain narrowing.Here we transform limited generation from 15 fs 94 central (λ c 755 nm 845 nm) bandwidth (130nm<∆λ<16 as well multi-color, time synchronized, sub-100 pulses user defined separation.The unique capabilities have been expanded into...
Carrier-envelope phase (CEP) stabilization of a femtosecond chirped-pulse amplification system featuring compact transmission grating compressor is demonstrated. The includes two stages and routinely generates phase-stable (~250 mrad rms) 2 mJ, 25 fs pulses at 1 kHz. Minimizing the optical pathway in enables without feedback control separation or beam pointing. We also demonstrate for first time to best our knowledge, out-of-loop CEP using an acousto-optic programmable dispersive filter...
We demonstrate for the first time (to our knowledge) characterization of ultrashort IR pulses by self-referenced spectral interferometry. Both sub-55-fs from 1.4 μm to 2 and broadband 2.5-cycle at 1.65 (13 fs FWHM) are characterized.
With the improvement of acceleration techniques, intrinsic emittance cathode has a strong impact on final brightness free electron laser. The systematic studies presented in this paper demonstrate for first time radiofrequency photocathode gun reduction when tuning laser photon energies close to effective work function copper. was determined by measuring core slice as beam size at wavelengths between 260 and 275 nm. results are consistent with measured cathode. Slice values normalized...
The authors present a simple add on for multicycle, multimJ Ti:sapphire-based amplifier systems to efficiently generate 9.5fs pulses with 1.8mJ. Filamentary propagation yields spectrally broadened carrying an unexpected large group-delay dispersion of −500fs2 which allows linear the few-cycle towards target areas without need any sophisticated control. Pulse compression could easily be achieved by transmission through combination different glass substrates. pulse wave front, low energy...
We provide what is believed to be the first experimental evidence of spatial control on multiple filamentation (MF) using circularly polarized femtosecond laser pulses. The exceptional shot-to-shot reproducibility MF pattern allowed complete characterization two copropagating high-energy filaments, revealing for time temporal (self-) compression filamenting pulses a fifth initial 57fs pulse duration without any sophisticated chirp control. Compared with LP MF, an enhancement in stability and...
Coherent manipulation of molecular wavepackets in biomolecules might contribute to the quest towards label-free cellular imaging and protein identification. We report use optimally tailored UV laser pulses pump–probe depletion experiments that selectively enhance or decrease fluorescence between two aromatic amino acids: tryptophan (Trp) tyrosine (Tyr). Selective modulation is achieved with a contrast ∼35%. A neat modification time-dependent signal Trp observed, while Tyr transient trace...
SwissFEL has a unique capability, among the normal conducting linac-based light sources, to simultaneously serve two separate undulator lines (Aramis and Athos) up machine repetition rate of 100 Hz using double bunch operation mode. It increases twice experiments throughput facility with modest additional investment. Two electron bunches spaced 28 ns apart are extracted from cathode by laser pulses individually controlled rates. The accelerated about 3 GeV in main linac same rf macropulse....
The determinist behavior of the femtosecond ablation process allows morphing features well under diffraction limit by utilizing thresholding effect, down to nanometer scale. Because there are a vast range applications where scaling size is major concern, we investigate use superresolving pupil plane filters. As known, these filters redistribute focused optical intensity for narrower bright spot and, as trade-off, increase sidelobes. However, this drawback can be rendered insignificant if all...
Experimental and simulation results of an electron gun test facility, based on pulsed diode acceleration followed by a two-cell rf cavity at 1.5 GHz, are presented here. The main features this diode-rf combination are: high peak gradient in the (up to $100\text{ }\text{ }\mathrm{MV}/\mathrm{m}$) obtained without breakdown conditioning, cathode shape providing electrostatic focusing, in-vacuum solenoid focus beam between cavity. Although stand was initially developed for testing field emitter...
Picosecond, flat-top, deep-UV pulses are needed to generate high-brightness electron beams efficiently drive x-ray free lasers. Current metal photocathodes have low efficiency and therefore require high-energy pulses, the generation of high-energy, flat-top in deep UV is still challenging. The efficiencies both harmonic pulse shapers restrict accessible energy. Moreover, acceptance bandwidth limits minimum rise time profile. We present few-hundred microjoule, picosecond, using chirp-matched...
Multispectral x-ray pump-probe experiments call for synchronized two-color free-electron lasers (FEL). This mode often implies a laborious setup or an inefficient use of the undulator. We report on simple and noninvasive approach tested at SwissFEL delivering almost 60% pulse energy compared with single color. In this new method, ps UV is overlapped to photocathode drive laser increasing beam emittance, which locally inhibits FEL process. scheme permits high-stability in spectrum control...
We present a bright and coherent soft x-ray source based on high harmonic generation delivering up to 1010 photons per second centered at 120 eV within an 80 bandwidth. The profits from fully phase-matched in unmodulated hollow waveguide. Under these conditions, the resulting spectrum is shown be flat-top cutoff photon energy line with theoretical single-atom response. characterized view of seeding free-electron laser overcome noise floor for wavelengths as short 8.9 nm. This opens...
Octave-spanning, 12.5 fs, (1.9 cycle) pulses with 115 {\mu}J energy in the short-wavelength mid-infrared spectral range (1-2.5 {\mu}m) have been generated via phase-mismatched cascaded nonlinear frequency conversion using organic DAST crystal. Such ultra-fast cascading effect is ensured by interaction of a pump pulse exceptionally large effective nonlinearity crystal and experiencing non-resonant, strongly phase mismatched, Kerr-like negative nonlinearity.
Several beam manipulation methods have been studied and experimentally demonstrated to generate x-ray multipulses in free-electron-laser (FEL) facilities, advancing the fields of material science, molecular physics, photochemistry by enabling pump/x-ray probe experiments. We a novel method hard using hybrid compression scheme. Compared other methods, this approach minimizes time jitter among FEL subpulses, produces large power is suitable for high repetition rate machines, since it does not...