Carrier-envelope phase-controlled quantum interference of injected photocurrents in semiconductors.
ABSTRACT We demonstrate quantum interference control of injected photocurrents in a semiconductor using the phase stabilized pulse train from a mode-locked Ti:sapphire laser. Measurement of the comb offset frequency via this technique results in a signal-to-noise ratio of 40 dB (10 Hz resolution bandwidth), enabling solid-state detection of carrier-envelope phase shifts of a Ti:sapphire oscillator.
Article: Characterization of carrier-envelope phase-sensitive photocurrent injection in a semiconductor[show abstract] [hide abstract]
ABSTRACT: We characterize the manner in which the carrier-envelope phase of ultrashort pulses can control quantum in-terference of injected photocurrents in low-temperature-grown gallium arsenide. We verify the predicted lin-ear and square-root dependences of the generated current on the average optical powers of the low () and high (2) frequency wings of a pulse spectrum, respectively. When scanning the time delay between these two col-ors, the signal amplitude exhibits a temporal width of 72 fs. The generated signal behaves as an ideal current source for loads below 100 k. This behavior allows us to increase the signal detection bandwidth from 25 kHz with a voltage amplifier to 830 kHz by use of a transimpedance amplifier; higher bandwidths are possible. We discuss how transimpedance amplification could also enable the quantum-interference photocurrent signal to be measured by use of materials with longer carrier lifetimes, such as intrinsic GaAs. © 2005 Optical So-ciety of America OCIS codes: 120.5050, 190.5970, 320.7100.
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ABSTRACT: The electric field of few-cycle laser pulses can be precisely controlled by controlling their “absolute” phase. Intense phase-stabilized few-cycle laser pulses give rise to novel effects in strong-field and above-threshold ionization (ATI). The phase dependence of the photoelectron spectra is a sensitive probe of the dynamics of the strong-field ionization processes underlying attosecond laser physics. Conversely, the phase-dependence of ATI spectra can be used for the measurement of the absolute phase. This, a summary of the experimental status of phase-dependent strong-field ionization, and a description of unsolved problems are the main points of this contribution.12/2008: pages 17-40;
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ABSTRACT: Carrier-envelope phase-stabilized laser pulses brought significant advances in investigating laser-solid interactions, as well, with the potential of revealing carrier dynamics in solids on unprecedented time-scales. More specifically, multi-photon induced photoemission from metals proved to be sensitive to the waveform of few-cycle pulses, however, underlying mechanisms are not fully understood. Combining surface plasmonic effects with photoemission demonstrates a potentially more promising approach to investigate laser-surface interactions induced by few-cycle pulses. Numerical results from a simple model on this phenomenon are presented. Related to this, previously unaddressed carrier-envelope phase phenomena in the vicinity of the focus are also considered.