Bøger af Sebastian Koke

The stabilization of the carrier-envelope phase of ultrashort laser pulseswent through a rapid development from the first publication of a feasibleconcept in 1999 to being a mature tool for frequency metrology and attosecondscience now. Using this technique, stabilization of the timing between thecarrier wave and the envelope of a laser pulse with residual jitters of only 100attoseconds has become possible. Naturally, the questions arises whether andhow this can be further improved.The current work is devoted to determining the physical mechanisms whichgenerate jitter in carrier-envelope phase stabilization. Furthermore, it is investigatedwhether there is a fundamental limitation to the achievable accuracy.To this end, two methods for removal of technical noise contributions areinitially discussed. Different interferometer topologies are investigated andspurious interferometer noise is reduced by more than 40% using a commonpathlayout. A novel two-detector based carrier-envelope phase retrieval techniquefor amplified laser pulses is demonstrated enabling the circumvention ofthe shot-noise constraint of the conventional extraction method to the maximumextent possible. Next, a novel feed-forward stabilization concept isdeveloped that enables carrier-envelope phase stabilizations with only 20 attosecondresidual timing jitter between carrier and envelope of the laser pulse.This feed-forward method is unconditionally stable against drop-out and permitsthe generation of a train of pulses with identical electric field structurewith no additional measures. As the feed-forward concept widely avoids thetechnical noise sources of the conventional feedback stabilization, the resultingnoise spectra exhibit only two unavoidable residual noise mechanisms: a highfrequencywhite noise floor stemming from shot noise in the carrier-envelopephase detection and a drift-like contribution with 1/f noise characteristics.Finally, the drift-like residual noise mechanism is found to induce phasenoise below the level expected for the conversion of pump laser shot noise intocarrier-envelope phase jitter. A feedback based squeezing, a photon-numbersqueezing process and a quantum non-demolition like conversion are discussedas possible explanations for this striking finding. It is shown that either thefeedback squeezing or the quantum non-demolition process is the probableorigin for the observed sub-shot-noise signatures of the carrier-envelope phasejitter.