Petahertz optoelectronics via attosecond control of solids

Zimin, Dmitry (2021): Petahertz optoelectronics via attosecond control of solids. Dissertation, LMU München: Fakultät für Physik

Abstract

Fast evolving technologies require faster data processing. Modern electronics possess physical limits for computation speed. To circumvent these limits new scientific approaches are required. Light is the fastest information carrier, therefore optoelectronic light-matter interaction can be potentially employed as a method towards much faster computation. In order to exploit light-matter interactions in the attosecond temporal and petahertz spectral domains, three main conditions should be fulfilled: a) techniques capable of detecting such fast processes must be available, b) physical mechanisms with an attosecond response time should be found and characterized, c) the methodology for storing and controlling of the information by means of these fast processes should be developed. This dissertation addresses these conditions and demonstrates the applicability of optoelectronics towards attosecond and petahertz domains. The thesis reports on novel approaches for the sampling of pulsed optical waveforms with attosecond temporal resolution and petahertz detection bandwidth, as well as their applications for time-resolved studies of attosecond non-equilibrium dynamics in solids and gases. It is demonstrated that the light-matter-light scheme of the optoelectronic interaction can be used to manipulate optical pulses waveforms, while optical pulses, in turn, can manipulate properties of matter. The temporal confinement of high-order non-linear excitation of charge carriers in dielectrics and gases is employed as a temporal gate for the sampling of pulsed waveforms. Non-symmetric displacement of photo-excited charges leads to polarization of a medium. Metal electrodes in the vicinity of the created polarization produce a measurable current. Gas pressure and distance to an electrode allow for control of the magnitude of the generated current and the detection sensitivity. The optimum signal in the air as the interaction medium is observed at around several mbar pressure. When the current signal is measured from two electrodes opposing each other, a 180-degree phase shift is observed, indicating that the polarization of a medium is the main mechanism responsible for the detected signal. Ultra-broadband photonic detection at near-petahertz and petahertz frequencies is demonstrated based on a heterodyne detection scheme. Pulsed waveform characterization with unstabilized carrier-envelope phase is demonstrated. The three-channel optical synthesizer is characterized by the novel methodology. Temporal confinement of the sampling channel allows extending the detection bandwidth of the electro-optic field sampling technique, for the first time, towards the visible spectral domain. Technological advances are applied to study and control non-steady-state dynamics in solids. The information encoded in the changes of optical pulse waveforms provides access to ultrafast processes occurring in a sample medium. The very first moments of a medium excitation and formation of optical properties are studied directly in the time domain. The dynamics of the formation of the non-equilibrium refractive index of a medium as well as thermalization of a non-equilibrium charge carrier distribution is studied in detail. The time delay associated with the plasma screening and non-linear excitation of a medium is observed experimentally and confirmed theoretically. Transient and long-lasting switching and modulation of optical properties are studied for silicon, diamond, and fused silica solids. The manipulation of pulsed optical waveforms based on light-matter-light interaction is demonstrated. The temporal confinement of the photo-excitation of a medium by an injection pulse is employed as a switch to induce localized and controllable changes on a pulse waveform. The control of the switching event in combination with the interacting test pulse provides a scheme towards manipulation of optical pulse waveforms as well as material properties in ultrafast time scale.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: optoelectronics, opto-electronics, ultrafast physics, attosecond physics, field-resolved metrology, ultrafast dynamics in solids
• Themengebiete: 500 Naturwissenschaften und Mathematik ; 500 Naturwissenschaften und Mathematik > 530 Physik
• Fakultäten: Fakultät für Physik
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 27. September 2021
• 1. Bericht­erstatter:in: Krausz, Ferenc