| 1. |
- Dacasa, Hugo, et al.
(författare)
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Single-shot extreme-ultraviolet wavefront measurements of high-order harmonics
- 2019
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Ingår i: Optics Express. - 1094-4087. ; 27:3, s. 2656-2670
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Tidskriftsartikel (refereegranskat)abstract
- We perform wavefront measurements of high-order harmonics using an extreme-ultraviolet (XUV) Hartmann sensor and study how their spatial properties vary with different generation parameters, such as pressure in the nonlinear medium, fundamental pulse energy and duration as well as beam size. In some conditions, excellent wavefront quality (up to 휆/11) was obtained. The high throughput of the intense XUV beamline at the Lund Laser Centre allows us to perform single-shot measurements of both the full harmonic beam generated in argon and individual harmonics selected by multilayer mirrors. We theoretically analyze the relationship between the spatial properties of the fundamental and those of the generated high-order harmonics, thus gaining insight into the fundamental mechanisms involved in high-order harmonic generation (HHG).
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| 2. |
- Fordell, Thomas, et al.
(författare)
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Carrier-envelope phase stabilization of a multi-millijoule, regenerative-amplifier-based chirped-pulse amplifier system
- 2009
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Ingår i: Optics Express. - 1094-4087. ; 17:23, s. 21091-21097
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Tidskriftsartikel (refereegranskat)abstract
- This article reports on the successful stabilization of the carrier-envelope phase of a 1-kHz laser system that includes a large grating stretcher, a regenerative amplifier, a multipass amplifier and a grating compressor. Phase stability for pulse energies up to 6 mJ is demonstrated using electronic feedback to the oscillator locking electronics as well as feedback via an acousto-optic programmable dispersive filter. (C) 2009 Optical Society of America
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| 3. |
- Fordell, Thomas, et al.
(författare)
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High-speed carrier-envelope phase drift detection of amplified laser pulses
- 2011
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Ingår i: Optics Express. - 1094-4087. ; 19:24, s. 23652-23657
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Tidskriftsartikel (refereegranskat)abstract
- An instrument for measuring carrier-envelope phase (CEP) drift of amplified femtosecond laser pulses at repetition rates up to the 100-kHz regime is presented. The device can be used for real-time pulse labeling and it could also enable single-loop CEP control of future high-repetition rate laser amplifiers. The scheme is demonstrated by measuring the CEP drift of a 1-kHz source. (C) 2011 Optical Society of America
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| 4. |
- Lorek, Eleonora, et al.
(författare)
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Size and shape dependent few-cycle near-field dynamics of bowtie nanoantennas
- 2015
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Ingår i: Optics Express. - 1094-4087. ; 23:24, s. 31460-31471
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Tidskriftsartikel (refereegranskat)abstract
- Metal nanostructures can transfer electromagnetic energy from femtosecond laser pulses to the near-field down to spatial scales well below the optical diffraction limit. By combining few-femtosecond laser pulses with photoemission electron microscopy, we study the dynamics of the induced few-cycle near-field in individual bowtie nanoantennas. We investigate how the dynamics depend on antenna size and exact bowtie shape resulting from fabrication. Different dynamics are, as expected, measured for antennas of different sizes. However, we also detect comparable dynamics differences between individual antennas of similar size. With Finite-difference time-domain simulations we show that these dynamics differences between similarly sized antennas can be due to small lateral shape variations generally induced during the fabrication.
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| 5. |
- Malm, Erik, et al.
(författare)
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Singleshot polychromatic coherent diffractive imaging with a high-order harmonic source
- 2020
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Ingår i: Optics Express. - 1094-4087. ; 28:1, s. 394-404
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Tidskriftsartikel (refereegranskat)abstract
- Singleshot polychromatic coherent diffractive imaging is performed with a high-intensity high-order harmonic generation source. The coherence properties are analyzed and several reconstructions show the shot-to-shot fluctuations of the incident beam wavefront. The method is based on a multi-step approach. First, the spectrum is extracted from double-slit diffraction data. The spectrum is used as input to extract the monochromatic sample diffraction pattern, then phase retrieval is performed on the quasi-monochromatic data to obtain the sample's exit surface wave. Reconstructions based on guided error reduction (ER) and alternating direction method of multipliers (ADMM) are compared. ADMM allows additional penalty terms to be included in the cost functional to promote sparsity within the reconstruction.
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| 6. |
- Matyschok, Jan, et al.
(författare)
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Temporal and spatial effects inside a compact and CEP stabilized, few-cycle OPCPA system at high repetition rates
- 2013
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Ingår i: Optics Express. - 1094-4087. ; 21:24, s. 29656-29665
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Tidskriftsartikel (refereegranskat)abstract
- We present a compact and ultra-stable few-cycle OPCPA system. In two non-collinear parametric amplification stages pulse energies up to 17 mu J at 200 kHz repetition rate are obtained. Recompression of the broadband pulses down to 6.3 fs is performed with chirped mirrors leading to peak powers above 800 MW. The parametric amplification processes were studied in detail employing (2 + 1) dimensional numerical simulations and compared to experimental observations in terms of spectral shapes, pulse energy, spatial effects as well as delay dependent nonlinear mixing products. This gives new insights into the parametric process and design guidelines for high repetition rate OPCPA systems. (C) 2013 Optical Society of America
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| 7. |
- Miranda, Miguel, et al.
(författare)
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Characterization of broadband few-cycle laser pulses with the d-scan technique
- 2012
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Ingår i: Optics Express. - 1094-4087. ; 20:17, s. 18732-18743
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Tidskriftsartikel (refereegranskat)abstract
- We present an analysis and demonstration of few-cycle ultrashort laser pulse characterization using second-harmonic dispersion scans and numerical phase retrieval algorithms. The sensitivity and robustness of this technique with respect to noise, measurement bandwidth and complexity of the measured pulses is discussed through numerical examples and experimental results. Using this technique, we successfully demonstrate the characterization of few-cycle pulses with complex and structured spectra generated from a broadband ultrafast laser oscillator and a high-energy hollow fiber compressor. (C)2012 Optical Society of America
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| 8. |
- Miranda, Miguel, et al.
(författare)
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Simultaneous compression and characterization of ultrashort laser pulses using chirped mirrors and glass wedges
- 2012
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Ingår i: Optics Express. - 1094-4087. ; 20:1, s. 688-697
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Tidskriftsartikel (refereegranskat)abstract
- We present a simple and robust technique to retrieve the phase of ultrashort laser pulses, based on a chirped mirror and glass wedges compressor. It uses the compression system itself as a diagnostic tool, thereby making unnecessary the use of complementary diagnostic tools. We used this technique to compress and characterize 7.1 fs laser pulses from an ultrafast laser oscillator. (C)2011 Optical Society of America
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| 9. |
- Sytcevich, Ivan, et al.
(författare)
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Few-cycle short-wave-infrared light source for strong-field experiments at 200 kHz repetition rate
- 2022
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Ingår i: Optics Express. - 1094-4087. ; 30:15, s. 27858-27867
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Tidskriftsartikel (refereegranskat)abstract
- We present a compact, few-cycle, short-wave infrared light source delivering 13 μJ, carrier-envelope phase (CEP) stable pulses around 2 μm, operating at 200 kHz repetition rate. Starting from an ytterbium fiber amplifier, the seed is produced via white-light generation followed by difference frequency generation, and later amplified in two BiBO nonlinear crystals. A pulse duration of 15.8 fs is measured with the dispersion scan technique, while the CEP stability is assessed via a monolithic spectral interferometry scheme. We demonstrate the potential of the system to drive strong-field experiments by performing high-order harmonic generation in argon gas.
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