Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas Cell
The generation of high-order harmonics in a semi-infinite cell by femtosecond laser pulses is a common practice for reliable coherent and low divergence XUV source beams for applications. Despite the relative simplicity of the experimental method, several phenomena coexist that affect the generated...
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2022-05-01
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| author | Stylianos Petrakis Makis Bakarezos Michael Tatarakis Emmanouil P. Benis Nektarios A. Papadogiannis |
| author_facet | Stylianos Petrakis Makis Bakarezos Michael Tatarakis Emmanouil P. Benis Nektarios A. Papadogiannis |
| author_sort | Stylianos Petrakis |
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| description | The generation of high-order harmonics in a semi-infinite cell by femtosecond laser pulses is a common practice for reliable coherent and low divergence XUV source beams for applications. Despite the relative simplicity of the experimental method, several phenomena coexist that affect the generated spectral and divergence characteristics of the high harmonic XUV frequency comb. The ionisation degree of the medium and the consequent plasma formation length imposes a spatiotemporal evolution of the fundamental EM field and XUV absorption. Varying the laser pulse chirp and the focusing conditions, as well as the gas density, we measured intense harmonic spectral and divergence variations attributed mainly to self-phase modulations of the laser EM field in the partially ionised medium. Additionally, low-divergence high harmonics are observed for certain laser chirp values attributed to the strong phase matching of only the short electron quantum path. Thus, a tunable, low divergent, and coherent XUV source can be realised for spatiotemporal imaging applications in the nanoscale. |
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| issn | 2218-2004 |
| language | English |
| last_indexed | 2024-03-10T00:25:27Z |
| publishDate | 2022-05-01 |
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| spelling | doaj.art-27190c59dc97486b8ee7c159bb1fb5502023-11-23T15:34:18ZengMDPI AGAtoms2218-20042022-05-011025310.3390/atoms10020053Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas CellStylianos Petrakis0Makis Bakarezos1Michael Tatarakis2Emmanouil P. Benis3Nektarios A. Papadogiannis4Department of Physics, University of Ioannina, 45110 Ioannina, GreeceInstitute of Plasma Physics and Lasers, Hellenic Mediterranean University Research Centre, 74100 Rethymno, GreeceInstitute of Plasma Physics and Lasers, Hellenic Mediterranean University Research Centre, 74100 Rethymno, GreeceDepartment of Physics, University of Ioannina, 45110 Ioannina, GreeceInstitute of Plasma Physics and Lasers, Hellenic Mediterranean University Research Centre, 74100 Rethymno, GreeceThe generation of high-order harmonics in a semi-infinite cell by femtosecond laser pulses is a common practice for reliable coherent and low divergence XUV source beams for applications. Despite the relative simplicity of the experimental method, several phenomena coexist that affect the generated spectral and divergence characteristics of the high harmonic XUV frequency comb. The ionisation degree of the medium and the consequent plasma formation length imposes a spatiotemporal evolution of the fundamental EM field and XUV absorption. Varying the laser pulse chirp and the focusing conditions, as well as the gas density, we measured intense harmonic spectral and divergence variations attributed mainly to self-phase modulations of the laser EM field in the partially ionised medium. Additionally, low-divergence high harmonics are observed for certain laser chirp values attributed to the strong phase matching of only the short electron quantum path. Thus, a tunable, low divergent, and coherent XUV source can be realised for spatiotemporal imaging applications in the nanoscale.https://www.mdpi.com/2218-2004/10/2/53high-order harmonic generationself-phase modulationsemi-infinite cellchirped laser pulses |
| spellingShingle | Stylianos Petrakis Makis Bakarezos Michael Tatarakis Emmanouil P. Benis Nektarios A. Papadogiannis Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas Cell Atoms high-order harmonic generation self-phase modulation semi-infinite cell chirped laser pulses |
| title | Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas Cell |
| title_full | Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas Cell |
| title_fullStr | Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas Cell |
| title_full_unstemmed | Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas Cell |
| title_short | Spectral and Divergence Characteristics of Plateau High-Order Harmonics Generated by Femtosecond Chirped Laser Pulses in a Semi-Infinite Gas Cell |
| title_sort | spectral and divergence characteristics of plateau high order harmonics generated by femtosecond chirped laser pulses in a semi infinite gas cell |
| topic | high-order harmonic generation self-phase modulation semi-infinite cell chirped laser pulses |
| url | https://www.mdpi.com/2218-2004/10/2/53 |
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