Attosecond Control of High Harmonic Photons Emission in Silicon Using Coherent Combination of ω-3ω Fields
Abstract
The field of high-intensity nonlinear optics offers a possibility to control a wide variety of phenomena directly by the waveform of the optical field, not by its envelope. The optical field-driven electron motion is then controlled with subcycle precision.
This highly time-resolved control enables the generation of sub-femtosecond photon and electron pulses representing the basis of attosecond physics. The generated pulses are, however, strongly coupled to the waveform of the driving optical field.
As a result, the study of ultrafast electron phenomena on the attosecond time scale requires precise and stable waveform tailoring of the driving field. We report on the development a two-color nonlinear interferometer which coherently combines the laser field with its third harmonic frequency for tailoring the nonlinear optical response of solids in the strong-field regime.
In our experiments we study high harmonic generation in silicon induced by coherent combination of ω-3ω fields. By changing the relative phase shift between the ω-3ω fields we shift the maximum of the driving field in time domain.
Consequently, we observe periodic modulation of high harmonic spectra generated in crystalline silicon induced by this waveform tailoring of two-color driving field. We also introduce spectral interference technique, where we combine original high harmonic pulse and its time-shifted replica with fixed phase to measure relative time shifts of high harmonic photons emission induced by changing the ω-3ω phase on attosecond time scale.
