Title The dynamics and optimization of the radiation of a femtosecond diode pumped Yb:KGW laser /
Translation of Title Puslaidininkiniais lazeriais kaupinamo Yb:KGW femtosekundinio lazerio veikos dinamika ir spinduliuotės parametrų optimizavimas.
Authors Pocius, Jonas
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Pages 54
Keywords [eng] Diode pumped ; Yb:KGW ; femtosecond laser
Abstract [eng] The objective of the present work is to examine the dynamics diode pumped femtosecond Yb:KGW laser consisting of an oscillator and a regenerative amplifier and to optimize its radiation parameters using the results obtained. The thermal-lens and nonlinear Kerr medium effect on the stability of the resonator has been studied. On the basis of the results obtained an oscillator which generates 31 fs pulses has been developed. To our knowledge they are the shortest pulses reported from the laser with a bulk ytterbium doped gain medium. We have also proposed and experimentally demonstrated the tilted pulse amplification method. Applying this method the scale of pulse stretching in the optical stretcher depends only on the beam size and the diffraction grating grooves density and does not depend on the bandwidth of the pulse. In order to optimized the compression of amplified pulses we have also proposed and experimentally tested a new design of single shot autocorrelator which disperses the given pulse spectrum by help of optical component with the angular dispersion. It this way the information is obtained about the distribution of various time-dependent spectral components with the resolution which depends only on the angular dispersion of the optical component used. The present method gives unambiguous characterization of the pulse compression which makes it less complex than widely used FROG, GRENOUILLI and SPIDER methods. The maximum pulse energy and the maximum output power limiting factors have been determined by examining the dynamics of diode pumped Yb:KGW regenerative amplifier. The research has enabled us to develop the original 6 W average output power femtosecond laser system generating 200 fs pulses up to 350 kHz pulse repetition rate or up to 1 mJ energy per pulse and to use it for pump of collinear and noncollinear optical parametric amplifiers.
Type Summaries of doctoral thesis
Language English
Publication date 2009