58 research outputs found

    Singleshot polychromatic coherent diffractive imaging with a high-order harmonic source

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    © 2020 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.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

    Characterizing ultrashort laser pulses with second harmonic dispersion scans

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    [EN]The dispersion scan (d-scan) technique has emerged as a simple-to-implement characterization method for ultrashort laser pulses. D-scan traces are intuitive to interpret and retrieval algorithms that are both fast and robust have been developed to obtain the spectral phase and the temporal pulse profile. Here, we shortly review the second harmonic generation d-scan technique, focusing predominantly on results obtained at the Lund Laser Centre. We describe and compare recent implementations for the characterization of few- and multi-cycle pulses as well as two different approaches for recording d-scan traces in a single shot, thus showing the versatility of the technique.Vetenskapsrådet (2013-8185, 2016-04907, 2019-06275); European Research Council (654148 Laserlab-Europe, proof of concept grant SISCAN-789992); Knut och Alice Wallenbergs Stiftelse; Junta de Castilla y León (SA136P20, SA287P18); Ministerio de Economía y Competitividad (EQC2018-004117-P, FIS2017-87970-R); Agência Nacional de Inovação (045932, 04/SI/2019, Projetos ID industrial à escala, PT2020); Fundação para a Ciência e a Tecnologia (‘Ultragraf’ M-ERA -NET4/0004/2016, PTDC/FIS-OTI/32213/2017, UIDB/04968/2020); Programa Operacional Temático Factores de Competitividade (NORTE-01-0145-FEDER-022096)

    Simultaneous compression and characterization of ultrashort laser pulses using chirped mirrors and glass wedges

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    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.Comment: 10 pages, 5 figure
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