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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Spectroscopic and acoustic study of controlled superfilamentsтезисы доклада Тезисы
- Авторы: Dmitry Pushkarev, Darya Uryupina, Danila Shipilo, Nikolai Panov, Anton Bychkov, Alexei Lar’kin, Ekaterina Mitina, Alexander Ushakov, Sergei Degtyarev, Svetlana Khonina, Elena Cherepenina, Alexander Shkurinov, Alexander Karabutov, Olga Kosareva, Andrei Savel’ev
- Сборник: The 6th International Symposium on Filamentation (COFIL2016)
- Тезисы
- Год издания: 2016
- Первая страница: 110
- Последняя страница: 110
- Аннотация: We present results of experimental and numerical study of controlled superfilament formation in the air by loosely focused femtosecond IR laser pulses. Radiation from TW Ti:Sa laser (50 mJ, 50 fs, 10 Hz, 7 mm FWHM beam) was focused by the lens with a focal length of 3 m. Pulse energy, autocorrelation trace and spectrum were detected in each laser shot. The transverse energy density of the beam was also measured in each laser shot by placing silica wedge 7-10 cm apart from the point of measurement along the filament and imaging the wedge surface on the 14 bit 1024x1024 CCD. Angularly resolved spectra of radiation inside a filament were measured by slicing a small part of radiation reflected from the first wedge by the other silica wedge. This radiation was focused to the input slit of the home made imaging spectrometer or ACTON SP- 500i spectrometer. The home-made spectrometer possessed less spectral band in a single shot, but higher dynamic range. ���� To trace a spatial structure of a filament and its formation we developed new diagnostics based on wideband (MHz) acoustic transducers. Transverse spatial resolution of in vivo measurements of a filament structure was better than 100 ����m [1]. This transducer was moved together with the first wedge along the filament. ���� We made comparative measurements within four different regimes of a filament formation: (i) a single filament, (ii) stochastic superfilamentation, (iii) amplitude or (iv) phase controlled superfilamentation. In the latter case amplitude or phase (diffractive optical element [2]) was introduced into the beam just before the main focusing lens. ���� In simulations we apply the Forward Maxwell equation with a carrier wave resolved. Our model includes the diffraction, dispersion, Kerr nonlinearity, self-consistent ionization and transient photocurrent of free electrons. Such the model can describe adequately the spectral transformation and energy absorption.
- Добавил в систему: Савельев-Трофимов Андрей Борисович