# FS-LA

 2017-04-1210:21 [PUBDB-2017-01661] Journal Article et al Jitter-correction for IR/UV-XUV pump-probe experiments at the FLASH free-electron laser New journal of physics 19(4), 043009 (2017) [10.1088/1367-2630/aa652d]   In pump-probe experiments employing a free-electron laser (FEL) in combination with a synchronized optical femtosecond laser, the arrival-time jitter between the FEL pulse and the optical laser pulse often severely limits the temporal resolution that can be achieved. Here, we present a pump-probe experiment on the UV-induced dissociation of 2,6-difluoroiodobenzene $(C_{6}H_{3}F_{2}I)$ molecules performed at the FLASH FEL that takes advantage of recent upgrades of the FLASH timing and synchronization system to obtain high-quality data that are not limited by the FEL arrival-time jitter. [...] OpenAccess: PDF; 2017-04-0608:33 [PUBDB-2017-01527] Journal Article et al Study on laser characteristics of Ho:YLF regenerative ampliers: Operation regimes, gain dynamics, and highly stable operation points Applied physics / B 123(4), 126 (2017) [10.1007/s00340-017-6704-0]   We present a comprehensive study of laser pulse amplification of Ho:YLF regenerative amplifiers (RAs) with respect to operation regimes, gain dynamics, and output pulse stability. The findings are expected to be more generic than for this specific gain material. [...] OpenAccess: PDF; 2017-02-2113:22 [PUBDB-2017-01061] Poster et al Ultrafast fragmentation dynamics of Phenanthrene and Pyrene after photoionization at 30.3 nm wavelength DESY User Meeting 2017, Meeting locationHamburg, Germany, 26 Jan 2017 - 27 Jan 2017 2017-01-1611:23 [PUBDB-2017-00571] Journal Article/Contribution to a conference proceedings/Contribution to a book et al High energetic and highly stable pulses from a Ho:YLF regenerative amplifier Solid State Lasers XXV: Technology and DevicesSolid State Lasers XXV: Technology and Devices, SPIE LASE, Meeting locationSan Francisco, California, 15 Jul 2016 - 20 Jul 2016 Proceedings of SPIE 9726, 97260S (2016) [10.1117/12.2212236]   We present results from our Ho:YLF regenerative amplifier (RA) producing up to 6.9 mJ at a repetition rate of 1 kHz and up to 12.9 mJ at a repetition rate of 10 Hz. At 1 kHz, we observe strongly bifurcating pulses, starting with certain round trip number, but the measurements identify a highly stable operation point that lies “hidden” beyond the instability region. [...] OpenAccess: PDF; 2017-01-1008:01 [PUBDB-2017-00371] Journal Article et al Low noise, tunable Ho:fiber soliton oscillator for Ho:YLF amplifier seeding Laser physics letters 13(6), 065104 (2016) [10.1088/1612-2011/13/6/065104]   We present a passively mode-locked, tunable soliton Ho:fiber ring oscillator, optimized for seeding of holmium-doped yttrium lithium flouride (Ho:YLF) amplifiers. The oscillator is independently tunable in central wavelength and spectral width from 2040 to 2070 nm and from 5 to 10 nm, respectively. [...] Restricted: PDF; 2017-01-1007:49 [PUBDB-2017-00366] Journal Article et al Out of the blue : semiconductor laser pumped visible rare-earth doped lasers Laser & photonics reviews 10(4), 548 - 568 (2016) [10.1002/lpor.201500290]   The rise of semiconductor-based pump sources such as In$_x$Ga$_{1-x}$N-laser diodes or frequency-doubled optically pumped semiconductor lasers with emission wavelengths in the blue encourages a revisitation of the rare-earth ions Pr$^{3+}$, Sm$^{3+}$, Tb$^{3+}$, Dy$^{3+}$, Ho$^{3+}$ and Er$^{3+}$ with respect to their properties as active ions in crystalline solid-state laser materials with direct emission in the visible spectral range. Nowadays, some of these blue-pumped visible lasers compete with Nd$^{3+}$-lasers in terms of efficiency and direct lasing at various colors from the cyan-blue to the deep red can be addressed in very simple and compact laser setups. [...] Published on 2016-04-24. Available in OpenAccess from 2017-04-24.: PDF; Restricted: PDF; 2017-01-1007:47 [PUBDB-2017-00365] Journal Article et al Transverse and longitudinal characterization of electron beams using interaction with optical near-fields Optics letters 41(15), 3435 - 3438 (2016) [10.1364/OL.41.003435]   We demonstrate an experimental technique for both transverse and longitudinal characterization of bunched femtosecond free electron beams. The operation principle is based on monitoring of the current of electrons that obtained an energy gain during the interaction with the synchronized optical near-field wave excited by femtosecond laser pulses. [...] Published on 2016-06-30. Available in OpenAccess from 2017-06-30.: PDF; Restricted: PDF; 2016-12-0710:20 [PUBDB-2016-05971] Report/Conference Presentation (Plenary/Keynote) team, X. c. Commissioning of the European XFEL Injector [TUOCA03] 7th International Particle Accelerator Conference, IPAC16, Meeting locationBusan, Korea, 8 May 2016 - 13 May 2016   The European XFEL Injector consists of an L-Band RF photoinjector, a TESLA type 1.3 GHz module, a 3rd har-monic RF section, a laser heater and an extensive diag-nostic section to determine projected and slice properties of the beam. The commissioning of the complete system has been started in December 2015 after several years of construction. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2016-11-2910:11 [PUBDB-2016-05694] Journal Article/Contribution to a conference proceedings et al Electron-Beam Manipulation Techniques in the SINBAD Linac for External Injection in Plasma Wake-Field Acceleration 2nd European Advanced Accelerator Concepts Workshop, EAAC2015, Meeting locationLa Biodola, Isola d'Elba, Italy, 13 Sep 2015 - 19 Sep 2015   The SINBAD facility(Short and INnovative Bunches and Accelerators at Desy)is foreseen to host various experiments in the field of production of ultra-short electron bunches and novel high gradient acceleration techniques. Besides studying novel acceleration techniques aiming to produce high brightness short electron bunches, the ARD group at DESY is working on the design of a conventional RF accelerator that will allow the production of low charge (0.5pC – fewpC) ultra-short electron bunches (having full width half maximum, FWHM, length r 1 fs – fewfs). [...] OpenAccess: PDF; Published on 2016-03-12. Available in OpenAccess from 2017-03-12.: PDF PDF (PDFA); 2016-11-2814:44 [PUBDB-2016-05682] Journal Article et al Time-resolved x-ray imaging of a laser-induced nanoplasma and its neutral residuals New journal of physics 18(4), 043017 (2016) [10.1088/1367-2630/18/4/043017]   The evolution of individual, large gas-phase xenon clusters, turned into a nanoplasma by a high power infrared laser pulse, is tracked from femtoseconds up to nanoseconds after laser excitation via coherent diffractive imaging, using ultra-short soft x-ray free electron laser pulses. A decline of scattering signal at high detection angles with increasing time delay indicates a softening of the cluster surface. [...] OpenAccess: PDF PDF (PDFA);