Thomas Nubbemeyer,
Martin Kaumanns,
Moritz Ueffing,
Martin Gorjan,
Ayman Alismail,
Hanieh Fattahi,
Jonathan Brons,
Oleg Pronin,
Helena G. Barros, et al.
Optics Letters
42
(7)
1381-1384
(2017)
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Near-PHz-bandwidth, phase-stable continua generated from a Yb:YAG thin-disk amplifier
Hanieh Fattahi,
Haochuan Wang,
Ayman Alismail,
Gunnar Arisholm,
Vladimir Pervak,
Abdallah M. Azzeer,
Ferenc Krausz
We report on the generation of a multi-octave, phase-stable continuum from the output of a Yb:YAG regenerative amplifier delivering 1-ps pulses with randomly varying carrier-envelope phase (CEP). The intrinsically CEP-stable spectral continuum spans from 450 nm to beyond 2500 nm, covering a spectral range of about 0.6 PHz. The generated coherent broadband light carries an energy of 4 mu J, which can be scaled to higher values if required. The system has been designed and is ideally suited for seeding broadband parametric amplifiers and multi-channel synthesizers pumped by picosecond Yb: YAG amplifiers, obviating the need for active timing synchronization required in previous approaches. The presented concept paves the way to cost-effective, reliable all-Yb:YAG single-cycle sources with terawatt peak-power and tens-of-Watts average power.
Sub-cycle light transients for attosecond, X-ray, four-dimensional imaging
Hanieh Fattahi
Contemporary Physics
57
(4)
580-595
(2016)
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Sub-cycle light transients for attosecond, X-ray, four-dimensional imaging
This paper reviews the revolutionary development of ultra-short, multi-TW laser pulse generation made possible by current laser technology. The design of the unified laser architecture discussed in this paper, based on the synthesis of ultrabroadband optical parametric chirped-pulse amplifiers, promises to provide powerful light transients with electromagnetic forces engineerable on the electron time scale. By coherent combination of multiple amplifiers operating in different wavelength ranges, pulses with wavelength spectra extending from less than 1 μm to more than 10 μm, with sub-cycle duration at unprecedented peak and average power levels can be generated. It is shown theoretically that these light transients enable the efficient generation of attosecond X-ray pulses with photon flux sufficient to image, for the first time, picometre-attosecond trajectories of electrons, by means of X-ray diffraction and record the electron dynamics by attosecond spectroscopy. The proposed system leads to a tool with sub-atomic spatio-temporal resolution for studying different processes deep inside matter.
High Energy and Short Pulse Lasers
(2016)
| Journal
In this chapter, the principle, design, and characteristics of high-efficiency, short-pulse-pumped, few-cycle optical parametric chirped-pulse amplification (OPCPA) systems are reviewed. To this end, the feasibility of two techniques to increase the conversion efficiency of few-cycle OPCPA systems is demonstrated and discussed. The techniques result in 2.5 mJ, 7.5 W pulses and correspond to a pump-to-signal conversion efficiency of 30%. The broadband amplified spectrum supports 5.7 fs. Finally, the feasibility of extending the amplified spectrum to a near-single-cycle regime by using the combination of different crystals and phase matching is shown.
Broadband beamsplitter for high intensity laser applications in the infra-red spectral range
Tatiana Amotchkina,
Hanieh Fattahi,
Yurij. A. Pervak,
Michael Trubetskov,
Vladimir Pervak
We report on design, production and characterization of an extremely broadband multilayer beamsplitter, covering wavelength range from 0.67 - 2.6 mu m. The group delay dispersion has small oscillations in the above mentioned working range. We used a new algorithm with floating constants allowing us to obtain a smooth and near constant GDD. The optical element based on the beamsplitter is used for dividing a low-energy super-octave spectrum into several sub-spectral regions which are later amplified and coherently combined.
Attosecond nonlinear polarization and light-matter energy transfer in solids
Annkatrin Sommer,
Elisabeth Bothschafter,
S. A. Sato,
Clemens Jakubeit,
Tobias Latka,
Olga Razskazovskaya,
Hanieh Fattahi,
Michael Jobst,
Hans Wolfgang Schweinberger, et al.
Electric-field-induced charge separation (polarization) is the most fundamental manifestation of the interaction of light with matter and a phenomenon of great technological relevance. Nonlinear optical polarization produces coherent radiation in spectral ranges inaccessible by lasers and constitutes the key to ultimate-speed signal manipulation. Terahertz techniques have provided experimental access to this important observable up to frequencies of several terahertz. Here we demonstrate that attosecond metrology extends the resolution to petahertz frequencies of visible light. Attosecond polarization spectroscopy allows measurement of the response of the electronic system of silica to strong (more than one volt per ångström) few-cycle optical (about 750 nanometres) fields. Our proof-of-concept study provides time-resolved insight into the attosecond nonlinear polarization and the light–matter energy transfer dynamics behind the optical Kerr effect and multi-photon absorption. Timing the nonlinear polarization relative to the driving laser electric field with sub-30-attosecond accuracy yields direct quantitative access to both the reversible and irreversible energy exchange between visible–infrared light and electrons. Quantitative determination of dissipation within a signal manipulation cycle of only a few femtoseconds duration (by measurement and ab initio calculation) reveals the feasibility of dielectric optical switching at clock rates above 100 terahertz. The observed sub-femtosecond rise of energy transfer from the field to the material (for a peak electric field strength exceeding 2.5 volts per ångström) in turn indicates the viability of petahertz-bandwidth metrology with a solid-state device.
Attosecond nonlinear polarization and light-matter energy transfer in solids
Annkatrin Sommer,
Elisabeth Bothschafter,
S. A. Sato,
Clemens Jakubeit,
Tobias Latka,
Olga Razskazovskaya,
Hanieh Fattahi,
Michael Jobst,
Hans Wolfgang Schweinberger, et al.
We demonstrate pulse shortening of 1-ps Yb:YAG thin-disk regenerative amplifier to 500 fs by cross-polarized wave generation (XPW) in a 6 mm BaF2 crystal. The process is self-compressed and has 8.5% conversion efficiency corresponding to 18 µJ energy. Our theoretical and experimental investigation shows that the factor of 3−−√ spectral broadening and pulse shortening in ps-XPW-generation only happens in unsaturated regime. We demonstrate that the initial spectral chirp affects the spectral broadening and pulse shortening of XPW pulses.
Self-compressed, spectral broadening of a Yb:YAG thin-disk amplifier
Theresa Buberl,
Ayman Alismail,
Haochuang Wang,
Nicholas Karpowicz,
Hanieh Fattahi
We report a 100 W, 20 mJ, 1-ps, all-Yb:YAG thin-disk regenerative amplifier seeded by a microjoule-level Yb:YAG thin-disk Kerr-lens mode-locked oscillator. The regenerative amplifier is implemented in a chirped pulse amplification system and operates at an ambient temperature in air, delivering ultrastable output pulses at a 5 kHz repetition rate and with a root mean square power noise value of less than 0.5%. Second harmonic generation of the amplifier’s output in a 1.5 mm-thick BBO crystal results in more than 70 W at 515 nm, making the system an attractive source for pumping optical parametric chirped pulse amplifiers in the visible and near-infrared spectral ranges.
