Waveform stability of intrapulse difference-frequency generation characterized via electro-optic sampling

Abstract

Controlling the electric field of trains of ultrashort laser pulses lies at the core of time-resolved measurements of the (consequences of) light-induced polarization in matter, as well as of precision measurements of quantum transitions. Intrapulse difference-frequency generation (IPDFG) affords such control intrinsically, producing waveform-stable pulses. Here, we employ electro-optic sampling as a broadband (both in the radio-frequency and in the optical domain), highly sensitive metrology for the stability of optical waveforms. In the 1-Hz-to-0.63-MHz band, we measure field amplitude fluctuations on the order of 0.2%, and temporal jitter between the center of mass of 16-fs near-infrared pulses spectrally centered at 1µm and driving IPDFG, and the emerging, nearly-octave-spanning mid-infrared field spectrally centered at 8.6 µm, of less than 4 as, corresponding to less than 1 mrad phase jitter. These results both confirm the outstanding phase stability of IPDFG, and provide a sensitivity high enough to investigate subtle effects of oscillator excess noise on the stability of waveforms generated via IPDFG.