Fourier-synthesis of optical waveforms

The talk will describe the generation of an optical pulse where the spectrum is sufficiently broad that the waveform is a single cycle in length, and where the temporal shape of this waveform may be synthesized. Specifically, we report the generation of a train of single-cycle optical pulses with a pulse width of 1.6 fs, a pulse separation of 11 fs, and a peak power of 1 MW. To synthesize a periodic waveform that is not sinusoidal, it is required that the radiation be phase coherent across its spectrum, and that the bandwidth of the radiation be large as compared to its central frequency. To obtain a multi-octave phase coherent spectrum, we use Q-switched laser pulses at 1.064 μm and 807 nm to drive the fundamental vibrational transition in deuterium slightly off resonance. An essential ingredient of the work that is described here is the use of non-resonant four-wave frequency mixing in xenon as a diagnostic for the generated pulses.