Doctoral Degrees (Physics)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/3640

Browse

Browsing Doctoral Degrees (Physics) by browse.metadata.advisor "Forbes, A."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    High brightness lasers
    (Stellenbosch : Stellenbosch University, 2015-04) Naidoo, Darryl; Forbes, A.; Rohwer, Erich G.; Stellenbosch University. Faculty of Science. Dept. of Physics.
  • Thumbnail Image
    Item
    Time domain ptychography
    (Stellenbosch : Stellenbosch University, 2015-04) Spangenberg, Dirk-Mathys; Rohwer, Erich G.; Neethling, Pieter H.; Forbes, A.; Stellenbosch University. Faculty of Science. Dept. of Physics.
    ENGLISH ABSTRACT: In this work we investigate a new method to measure the electric field of ultrafast laser pulses by extending a known measurement technique, ptychography, in the spatial domain to the time domain which we call time domain ptychography. The technique requires the measurement of intensity spectra at different time delays of an unknown temporal object and a known probe pulse. We show for the first time by measurement and calculation that this technique can be applied with excellent results to recover both the amplitude and phase of a temporal object. This technique has several advantages, such as fast convergence, the resolution is limited by the usable measured spectral bandwidth and the recovered phase has no sign ambiguity. We then extend the technique to pulse characterization where the probe is derived form the temporal object by filtering meaning the probe pulse is also unknown, but the spectrum of the probe pulse must be the same as the spectrum of the temporal object before filtering. We modify the reconstruction algorithm, now called ptychographic iterative reconstruction algorithm for time domain pulses (PIRANA), in order to also reconstruct the probe and we show for the first time that temporal objects, a.k.a laser pulses, can be reconstructed with this new modality.