| 1. |
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| 2. |
- Balla, Prannay, et al.
(author)
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Post-compression of picosecond pulses to four optical cycles
- 2020
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In: High Intensity Lasers and High Field Phenomena, HILAS 2020. - 9781557528209
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Conference paper (peer-reviewed)abstract
- We report post-compression of 1.2 ps pulses into the few-cycle regime via multi-pass spectral broadening. We achieve compression factors of 40 in single and 93 in a dual stage scheme using a compact setup.
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| 3. |
- Balla, Prannay, et al.
(author)
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Postcompression of picosecond pulses into the few-cycle regime
- 2020
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In: Optics Letters. - 0146-9592. ; 45:9, s. 2572-2575
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Journal article (peer-reviewed)abstract
- In this work,we demonstrate postcompression of 1.2 ps laser pulses to 13 fs via gas-based multipass spectral broadening. Our results yield a single-stage compression factor of about 40 at 200 W in-burst average power and a total compression factor >90 at reduced power. The employed scheme represents a route toward compact few-cycle sources driven by industrial-grade Yb:YAG lasers at high average power.
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| 4. |
- de Oliveira, Vinicius Silva, et al.
(author)
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Intensity noise optimization of a mid-infrared frequency comb difference-frequency generation source
- 2020
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In: Optics Letters. - 0146-9592 .- 1539-4794. ; 45:7, s. 1914-1917
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Journal article (peer-reviewed)abstract
- We experimentally demonstrate in a difference-frequency generation mid-infrared frequency comb source the effect of temporal overlap between pump and signal pulses on the relative intensity noise (RIN) of the idler pulse. When scanning the temporal delay between our 130 fs long signal and pump pulses, we observe a RIN minimum with a 3 dB width of 20 fs delay and a RIN increase of 20 dB in 40 fs delay at the edges of this minimum. We also demonstrate active long-term stabilization of the mid-infrared frequency comb source to the temporal overlap setting corresponding to the lowest RIN operation point by an online RIN detector and active feedback control of the pump-signal pulse delay. This active stabilization setup allows us to dramatically increase the signal-to-noise ratio of mid-infrared absorption spectra. (C) 2020 Optical Society of America
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| 5. |
- Escoto, Esmerando, et al.
(author)
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Role of dispersion and compression ratio on the temporal contrast of SPM-broadened post-compressed pulses
- 2021
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In: 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021. - 9781665418768
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Conference paper (peer-reviewed)abstract
- Nonlinear pulse post-compression, mainly enabled by self-phase modulation (SPM), opens new avenues towards high peak power laser pulses at high average power while bypassing the need for a gain medium with large bandwidth. However, SPM-induced spectral broadening typically introduces spectral amplitude modulations as well as a chirp of third and higher orders, limiting the temporal contrast of the compressed pulse. While some recent works address this issue and discuss mitigation strategies [1] , [2] , not much attention has been devoted to the physical processes and limitations that determine the temporal contrast of post-compressed pulses. As novel compression techniques expand the achievable compression ratio [3] , it is increasingly important to fully understand the underlying pulse quality limitations. Here, we outline the role of two important characteristics - dispersion and compression ratio - on the temporal quality of post-compressed pulses. Using both numerical simulations as well as experimental tests employing a gas-filled multi-pass cell (MPC), we study the temporal contrast of post-compressed pulses over large compression-ratio and dispersion range. Using a 730 fs input pulse we were able to generate a 55 fs post-compressed pulse with up to 78% energy contained in the main compressed pulse (defined via the first local minima near the highest peak) against its picosecond background.
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| 6. |
- Escoto, Esmerando, et al.
(author)
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Temporal quality of post-compressed pulses at large compression factors
- 2022
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In: Journal of the Optical Society of America B: Optical Physics. - 0740-3224. ; 39:7, s. 1694-1702
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Journal article (peer-reviewed)abstract
- Post-compression of ultra-short laser pulses via self-phase modulation is routinely employed for the generation of laser pulses with optical bandwidths reaching far beyond the laser gain limitations. Although high compression factors can be routinely achieved, the compressed pulses typically suffer from temporal quality degradation. We numerically and experimentally analyze the deterioration of different measures of temporal quality with increasing compression factor and show how appropriate dispersion management and cascading of the post-compression process can be employed to limit the impact of this effect. The demonstrated saturation of pulse quality degradation at large compression factors puts novel femtosecond laser architectures based on post-compressed picosecond or even nanosecond laser systems in sight.
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| 7. |
- Heyl, Christoph M., et al.
(author)
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High-energy bow tie multi-pass cells for nonlinear spectral broadening applications
- 2022
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In: JPhys Photonics. - : IOP Publishing. - 2515-7647. ; 4:1
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Journal article (peer-reviewed)abstract
- Multi-pass cells (MPCs) have emerged as very attractive tools for spectral broadening and post-compression applications. We discuss pulse energy limitations of standard MPCs considering basic geometrical scaling principles and introduce a novel energy scaling method using a MPC arranged in a bow tie geometry. Employing nonlinear pulse propagation simulations, we numerically demonstrate the compression of 125 mJ, 1 ps pulses to 50 fs using a compact 2 m long setup and outline routes to extend our approach into the Joule-regime.
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| 8. |
- Heyl, Christoph M., et al.
(author)
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Pulse energy scaling of multi-pass cells for nonlinear spectral broadening applications
- 2022
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In: CLEO : Science and Innovations, S and I 2022 - Science and Innovations, S and I 2022. - 9781557528209
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Conference paper (peer-reviewed)abstract
- We discuss basic pulse energy scaling principles for multi-pass cells (MPCs) and introduce a novel multi-pass cell type which we employ to numerically predictpost-compression of 125 mJ pulses using a 2 m setup.
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| 9. |
- Rajhans, Supriya, et al.
(author)
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Post-compression of multi-millijoule picosecond pulses to few-cycles approaching the terawatt regime
- 2023
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In: Optics Letters. - 0146-9592. ; 48:18, s. 4753-4756
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Journal article (peer-reviewed)abstract
- Advancing ultrafast high-repetition-rate lasers to shortest pulse durations comprising only a few optical cycles while pushing their energy into the multi-millijoule regime opens a route toward terawatt-class peak powers at unprecedented average power. We explore this route via efficient post-compression of high-energy 1.2 ps pulses from an ytterbium InnoSlab laser to 9.6 fs duration using gas-filled multi-pass cells (MPCs) at a repetition rate of 1 kHz. Employing dual-stage compression with a second MPC stage supporting a close-to-octave-spanning bandwidth enabled by dispersion-matched dielectric mirrors, a record compression factor of 125 is reached at 70% overall efficiency, delivering 6.7 mJ pulses with a peak power of ∼0.3 TW. Moreover, we show that post-compression can improve the temporal contrast at multi-picosecond delay by at least one order of magnitude. Our results demonstrate efficient conversion of multi-millijoule picosecond lasers to high-peak-power few-cycle sources, prospectively opening up new parameter regimes for laser plasma physics, high energy physics, biomedicine, and attosecond science.
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| 10. |
- Schönberg, Arthur, et al.
(author)
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Energy-Scaling of Multi-Pass Cell Post-Compression : The Bow Tie MPC Scheme
- 2022
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In: Proceedings of the 2022 Conference on Lasers and Electro-Optics Pacific Rim.
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Conference paper (peer-reviewed)abstract
- We introduce the bow tie multi-pass cell as a new scheme for post-compression of high-energy laser pulses, overcoming current limits of Herriott-type multi-pass cell-based post-compression imposed mainly by mirror damage threshold limitations.
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| 11. |
- Viotti, Anne Lise, et al.
(author)
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60 fs, 1030 nm FEL pump-probe laser based on a multi-pass post-compressed Yb:YAG source
- 2021
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In: Journal of Synchrotron Radiation. - 0909-0495. ; 28, s. 36-43
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Journal article (peer-reviewed)abstract
- This paper reports on nonlinear spectral broadening of 1.1 ps pulses in a gas-filled multi-pass cell to generate sub-100 fs optical pulses at 1030 nm and 515 nm at pulse energies of 0.8 mJ and 225 μJ, respectively, for pump-probe experiments at the free-electron laser FLASH. Combining a 100 kHz Yb:YAG laser with 180 W in-burst average power and a post-compression platform enables reaching simultaneously high average powers and short pulse durations for high-repetition-rate FEL pump-probe experiments.
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| 12. |
- Viotti, Anne Lise, et al.
(author)
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Few-cycle pulse generation by double-stage hybrid multi-pass multi-plate nonlinear pulse compression
- 2023
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In: Optics Letters. - 0146-9592. ; 48:4, s. 984-987
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Journal article (peer-reviewed)abstract
- Few-cycle pulses present an essential tool to track ultrafast dynamics in matter and drive strong field effects. To address photon-hungry applications, high average power lasers are used which, however, cannot directly provide sub-100-fs pulse durations. Post-compression of laser pulses by spectral broadening and dispersion compensation is the most efficient method to overcome this limitation. We present a notably compact setup which turns a 0.1-GW peak power, picosecond burst-mode laser into a 2.9-GW peak power, 8.2-fs source. The 120-fold pulse duration shortening is accomplished in a two-stage hybrid multi-pass, multi-plate compression setup. To our knowledge, neither shorter pulses nor higher peak powers have been reported to-date from bulk multi-pass cells alone, manifesting the power of the hybrid approach. It puts, for instance, compact, cost-efficient, and high repetition rate attosecond sources within reach.
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| 13. |
- Viotti, Anne Lise, et al.
(author)
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Intra-Burst Pulse Characterization of a High-Power Post-Compressed Yb:YAG Laser at 100 kHz Repetition Rate
- 2021
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In: 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021. - 9781665418768
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Conference paper (peer-reviewed)abstract
- High-average power Ytterbium (Yb) laser systems are playing an increasingly important role in ultrafast science e.g. as pump lasers for optical parametric amplifiers or directly as ultrafast sources. The gain bandwidth of Yb limits the pulse duration to a few 100 fs up to about 1 ps. However, many applications, such as attosecond physics or X-ray Free Electron Laser (FEL) science, would greatly benefit from the combination of high average powers with much shorter pulses, achievable via post-compression. Nonlinear pulse post-compression of high-average power Yb lasers employing multi-pass cell (MPC) -based spectral broadening [1], [2] was recently implemented for two burst-mode pump-probe lasers at the FEL facility FLASH in Hamburg [3], [4]. For such lasers, precise characterization and control of intra-burst pulse dynamics is crucial as the post-compression process couples input pulse energy instabilities with important output pulse parameters such as spectrum, pulse length and temporal contrast. Here, we demonstrate 100 kHz intra-burst spectrum, phase and temporal contrast characterization of a Yb:YAG Innoslab burst-mode amplifier post-compressed in a gas-filled MPC. Our measurements reveal a stable broadened spectrum and compressed pulse duration within the flat part of the burst, yielding a relative energy content of about 80% in the main compressed fs pulse (250 fs window versus 4 ps background pedestal).
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| 14. |
- Viotti, Anne Lise, et al.
(author)
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Intra-burst temporal pulse contrast of a high-power post-compressed picosecond Yb:YAG laser
- 2021
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In: Conference on Laser and Electro-Optics : Science and Innovations, CLEO:S and I 2021 - Science and Innovations, CLEO:S and I 2021. - 9781557528209
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Conference paper (peer-reviewed)abstract
- We report on pulse contrast characterization of the output of a gas-filled multi-pass cell employed for 20-fold compression of a high-power Yb:YAG laser. We demonstrate an energy content of 80% in the compressed fs pulse.
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| 15. |
- Viotti, Anne Lise, et al.
(author)
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Multi-pass cells for post-compression of ultrashort laser pulses
- 2022
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In: Optica. - 2334-2536. ; 9:2, s. 197-216
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Journal article (peer-reviewed)abstract
- Ultrafast lasers reaching extremely high powers within short fractions of time enable a plethora of applications. They grant advanced material processing capabilities, are effective drivers for secondary photon and particle sources, and reveal extreme light-matter interactions. They also supply platforms for compact accelerator technologies, with great application prospects for tumor therapy or medical diagnostics. Many of these scientific cases benefit from sources with higher average and peak powers. Following mode-locked dye and titanium-doped sapphire lasers, broadband optical parametric amplifiers have emerged as high peak- and average power ultrashort pulse lasers.Amuch more powerefficient alternative is provided by direct post-compression of high-power diode-pumped ytterbium lasers-a route that advanced to another level with the invention of a novel spectral broadening approach, the multi-pass cell technique. The method has enabled benchmark results yielding sub-50-fs pules at average powers exceeding 1 kW, has facilitated femtosecond post-compression at pulse energies above 100 mJ with large compression ratios, and supports picosecond to few-cycle pulses with compact setups. The striking progress of the technique in the past five years puts light sources with tens to hundreds of TW peak and multiple kW of average power in sight-an entirely new parameter regime for ultrafast lasers. In this review, we introduce the underlying concepts and give brief guidelines for multi-pass cell design and implementation. We then present an overview of the achieved performances with both bulk and gas-filled multipass cells.Moreover, we discuss prospective advances enabled by this method, in particular including opportunities for applications demanding ultrahigh peak-power, high repetition rate lasers such as plasma accelerators and laser-driven extreme ultraviolet sources.
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| 16. |
- Viotti, Anne Lise, et al.
(author)
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Temporal pulse quality of a Yb:YAG burst-mode laser post-compressed in a multi-pass cell
- 2021
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In: Optics Letters. - 0146-9592. ; 46:18, s. 4686-4689
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Journal article (peer-reviewed)abstract
- Nonlinear pulse post-compression represents an efficient method for ultrashort, high-quality laser pulse production. The temporal pulse quality is, however, limited by amplitude and phase modulations intrinsic to post-compression. We here characterize in frequency and time domain with high dynamic range individual post-compressed pulses within laser bursts comprising 100-kHz-rate pulse trains. We spectrally broaden 730 fs, 3.2 mJ pulses from a Yb:YAG laser in a gas-filled multi-pass cell and post-compress them to 56 fs. The pulses exhibit a nearly constant energy content of 78% in the main peak over the burst plateau, which is close to the theoretical limit. Our results demonstrate attractive pulse characteristics, making multi-pass post-compressed lasers very applicable for pump–probe spectroscopy at, e.g., free-electron lasers or as efficient drivers for secondary frequency conversion stages.
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