Sökning: "pulse shaping"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden pulse shaping.

  1. 1. Measurement and Control of Attosecond Light Fields

    Författare :Erik Mansten; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pulse characterization; Spectral signature; Two-color generation; Pulse compression; Attosecond pulse trains; High-order harmonics; Pulse shaping; Tunable; Fysicumarkivet A:2009:Mansten;

    Sammanfattning : Attosecond pulses are used to study electron dynamics in atoms and molecules. In this thesis, schemes to control the generation of attosecond pulses and pulse-shaping techniques to compress the pulses are presented. Generation of attosecond pulses requires high intensity, which is reached by focusing a pulsed femtosecond laser. LÄS MER

  3. 2. Pulse Shape Adaptation and Channel Estimation in Generalised Frequency Division Multiplexing Systems

    Författare :Jinfeng Du; Svante Signell; Ben Slimane; Arne Svenssons; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; OFDM; GFDM; OQAM; pulse shaping; adaptation; channel estimation; Electronics; Elektronik;

    Sammanfattning : Orthogonal Frequency Division Multiplexing (OFDM) is well known as an efficient technology for wireless communications and is widely used in many of the current and upcoming wireless and wireline communication standards. However, it has some intrinsic drawbacks, e.g. LÄS MER

  4. 3. Time-Resolved Photoemission Electron Microscopy: Development and Applications

    Författare :Lukas Wittenbecher; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PEEM; time-resolved PEEM; ultrafast optics; pulse shaping; plasmonics; semiconductor nanowires; hot electrons; ultrafast microscopy; charge carrier relaxation;

    Sammanfattning : Time-resolved photoemission electron microscopy (TR-PEEM) belongs to a class of experimental techniquescombining the spatial resolution of electron-based microscopy with the time resolution of ultrafast opticalspectroscopy. This combination provides insight into fundamental processes on the nanometer spatial andfemto/picosecond time scale, such as charge carrier transport in semiconductors or collective excitations ofconduction band electrons at metal surfaces. LÄS MER

  5. 4. Constructing and Commissioning HELIOS – A High Harmonic Generation Source for Pump-Probe Measurements with sub 50 fs Temporal Resolution : The Development of Experimental Equipment for Extreme Ultraviolet Spectroscopy

    Författare :Joachim A. Terschlüsen; Johan Söderström; Margaret Murnane; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Angle-resolved photoemission spectroscopy; Angle resolved photoemission spectroscopy; Angle-resolved time-of-flight; Angle resolved time of flight; ARTOF; ARPES; tr-ARPES; fs; fs resolution; Fourier transform spectrometer; Fourier-transform spectrometer; Fourier transform spectroscopy; Fourier-transform spectroscopy; FTS; gas cell; high harmonic generation; laser; liquid jet; monochromator; HELIOS; HHG; off-plane mount; off plane mount; OPA; optical parametric amplifier; PCPDTBT; pulse shaping; pump probe; pump-probe measurements; pump-probe measurements; pump-probe spectroscopy; pump-probe spectroscopy; Rowland spectrometer; time-of-flight spectrometer; time of flight spectrometer; TOF; time-resolved spectroscopy; time resolved spectroscopy; time-resolved experiments; time resolved experiments; T-MOKE; tr-PES; PES; photoelectron spectroscopy; transverse magneto optical Kerr effect; transverse magneto-optical Kerr effect; ultrafast; ultra-high vacuum; ultra high vacuum; UHV; XUV; VUV; X-rays; Permalloy; magnetization dynamic; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : This thesis presents HELIOS, an in-house laboratory for time-resolved pump-probe spectroscopy with extreme-ultraviolet (XUV) probe radiation. A wide span of pump wavelengths can be generated using commercial laser equipment while XUV probe radiation is generated via a high harmonic generation process in a noble gas delivering probe photons with energies between 20 eV and 72 eV. LÄS MER

  7. 5. Generation and Applications of Picosecond Pulses in High-Capacity Fiber Optic Systems

    Författare :Jie Li; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear distortion; optical pulse shaping; dispersion-management; eye-diagram; cross-phase modulation; optical sampling; optical fiber applications; multiplexing; parametric amplification; demultiplexing; optical pulses; fiber optical communication; nonlinear systems; time division multiplexing; four-wave mixing; polarization-mode dispersion; optical signal processing; fiber optical nonlinearities; fiber ring laser; soliton robustness; mode-locking; optical filters; networks;

    Sammanfattning : This thesis deals with short optical pulse generation from actively mode-locked Erbium-doped fiber ring lasers (ML-EFRL) and their applications in all-optical signal processing (optical sampling and switching) and transmission experiments for high-capacity fiber optic systems. In future ultra-high bit-rate optical time division multiplexed (OTDM) systems, one of the key requirements is to develop reliable optical pulse sources that can generate high quality optical pulses. LÄS MER