1. Béla Balázs and the Eye of the MicroscopeEszter Polonyi, 2012, original scientific article Abstract: This study explores the significance of the cinematic close-up to one of the earliest theories of film, produced by Béla Balázs, on the basis of a widespread technique of microscopy in the life sciences, notably in the work of his brother Evin Bauer, a theorist of microbiology. Balázs imagines that silent film records life in its immanence and spontaneity by virtue of what he calls the “physiognomic” nature of its signs. Rather than generating signs that must be passed through an alphabetic cipher, as had been required under the regime of the written or literary, Balázs presents film as liberating our access to the flow of optical data. Interestingly, however, Balázs retains the need otherwise characteristic of scientific analysis for dividing up the image into semiotic units, what he describes as “atomization.” He insists on returning the real to a symbolic order and making film into a language.
Found in: ključnih besedah
Summary of found: ...film history, media studies, science and technology studies, Weimar cinema, media archaeology...
Keywords: film history, media studies, science and technology studies, Weimar cinema, media archaeology
Published: 10.12.2020; Views: 1987; Downloads: 0
 Fulltext (10,81 MB) |
2. Advantages and disadvantages of experiments with ultrashort two-color pulsesMatija Stupar, 2020, doctoral dissertation Abstract: Advances in the development of lasers have led to a new class of radiation sources generating coherent, tunable, ultrashort light pulses in the spectral region ranging from infrared to soft X-rays. This includes high-order harmonics generation in gas (HHG), on which relies the CITIUS facility at University of Nova Gorica (Slovenia), and free-electron lasers (FELs), such as the facility FERMI at Elettra-Sincrotrone Trieste (Italy). The distinctive structure of HHG and FEL radiation paved the way to time-resolved experiments, which are performed to investigate events occurring on a short, or very short, temporal scale, from picoseconds to femtoseconds.
This work focuses on the advantages and disadvantages of some experimental techniques based on using these novel light sources to investigate the microscopic and/or ultrafast dynamics of matter samples, which have been previously driven out of equilibrium.
Advantages rely on the implementation of various applications based on two-color schemes and, more specifically, include the possibility of acquiring two-dimensional frequency maps, measuring electrons’ effective masses, or investigating electronic properties decoupled from the influence of the lattice. Particular focus will be put on experimental methods relying on photoelectric effect and photoelectron spectroscopy. In all experiments, we took advantage of one or more specific properties of HHG and FEL sources, such as controllable chirp, to study laser dressed states in helium, variable polarization, to study electronic properties of iron-based pnictides and ultrashort pulses (< 10 fs) to study the purely electronic dynamics in transition metal dichalcogenides.
On the other hand, the study of the interface between a molecule and a topological insulator revealed some intrinsic limitations and physical drawbacks of the technique, such as spurious effects originating from the high power pulses, like multiphoton absorption and the space charge effect, or the reduction of experimental resolution when pushing for shorter and shorter pulse durations. Some disadvantages are also connected to the current state-of-the-art in the field of ultrashort laser systems, where a trade-off needs to be found between repetition rate and laser power.
Finally, state-of-the-art experiments based on the ability to generate ultrashort pulses carrying orbital angular momentum in visible, near-infrared as well as extreme UV range will be presented. The use of these pulses opens the door to the investigation of new physical phenomena, such as probing magnetic vortices using extreme ultraviolet light from a free-electron laser or imprinting the spatial distribution of an ultrashort infrared pulse carrying orbital angular momentum onto a photoelectron wave packet.
Found in: ključnih besedah
Summary of found: ...harmonic generation, free-electron lasers, hot-electrons dynamics, surface science, pump-probe photoemission, ultraviolet photoemission, orbital angular momentum...
Keywords: ultrafast lasers, two-color experiments, photoemission, high-order harmonic generation, free-electron lasers, hot-electrons dynamics, surface science, pump-probe photoemission, ultraviolet photoemission, orbital angular momentum
Published: 02.12.2020; Views: 2739; Downloads: 100
Fulltext (19,78 MB) |
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4. The Future of Film: Appropriation rather than PreservationEszter Polonyi, unpublished conference contribution Found in: ključnih besedah
Summary of found: ...film studies, art history, library and data science, archive theory, contemporary art, intangible heritage, cultural...
Keywords: film studies, art history, library and data science, archive theory, contemporary art, intangible heritage, cultural heritage
Published: 11.12.2020; Views: 1865; Downloads: 0
Fulltext (1,16 MB) |
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6. 'The Tragedy is Anatomical': Microscopes and Faces in Jean Epstein and Béla BalázsEszter Polonyi, unpublished conference contribution Found in: ključnih besedah
Summary of found: ...film theory, media studies, science and technology studies, silent cinema, biology...
Keywords: film theory, media studies, science and technology studies, silent cinema, biology
Published: 11.12.2020; Views: 1686; Downloads: 0
Fulltext (726,28 KB) |
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9. Self-amplified photo-induced gap quenching in a correlated electron materialJurij Urbančič, Eich Steffen, Mathias Stefan, 2016, original scientific article Abstract: Capturing the dynamic electronic band structure of a correlated material presents a powerful capability for uncovering the complex couplings between the electronic and structural degrees of freedom. When combined with ultrafast laser excitation, new phases of matter can result, since far-from-equilibrium excited states are instantaneously populated. Here, we elucidate a general relation between ultrafast non-equilibrium electron dynamics and the size of the characteristic energy gap in a correlated electron material. We show that carrier multiplication via impact ionization can be one of the most important processes in a gapped material, and that the speed of carrier multiplication critically depends on the size of the energy gap. In the case of the charge-density wave material 1T-TiSe 2 , our data indicate that carrier multiplication and gap dynamics mutually amplify each other, which explains—on a microscopic level—the extremely fast response of this material to ultrafast optical excitation.
Self-amplified photo-induced gap quenching in a correlated electron material. Available from: https://www.researchgate.net/publication/308804379_Self-amplified_photo-induced_gap_quenching_in_a_correlated_electron_material [accessed Apr 20, 2017].
Found in: ključnih besedah
Keywords: high harmonic generation, charge-density wave material, 1T-TiSe2, non-equilibrium electron dynamics, ultrafast surface science
Published: 20.04.2017; Views: 4709; Downloads: 0
Fulltext (1,10 MB) |
10. Time- and angle-resolved photoemission spectroscopy with optimized high-harmonic pulses using frequency-doubled Ti:Sapphire lasersSteffen Eich, Jurij Urbančič, 2014, original scientific article Abstract: Time- and angle-resolved photoemission spectroscopy (trARPES) using femtosecond extreme ultraviolet high harmonics has recently emerged as a powerful tool for investigating ultrafast quasiparticle dynamics in correlated-electron materials. However, the full potential of this approach has not yet been achieved because, to date, high harmonics generated by 800 nm wavelength Ti:Sapphire lasers required a trade-off between photon flux, energy and time resolution. Photoemission spectroscopy requires a quasi-monochromatic output, but dispersive optical elements that select a single harmonic can significantly reduce the photon flux and time resolution. Here we show that 400 nm driven high harmonic extreme-ultraviolet trARPES is superior to using 800 nm laser drivers since it eliminates the need for any spectral selection, thereby increasing photon flux and energy resolution to <150 meV while preserving excellent time resolution of about 30 fs.
Found in: ključnih besedah
Keywords: angle-resolved photoemission spectroscopy, ARPES, high harmonic generation, ultrafast surface science
Published: 20.04.2017; Views: 4459; Downloads: 0
Fulltext (1,80 MB) |
