Sub-cycle Field Sampling of Degenerate Four Wave Mixing Signals

When intense ultrashort laser light interacts with matter nonlinear optical effects become important. Such nonlinear interactions result in the emission of ultrashort pulses that carry the signatures of electron dynamics. Measuring such signal electric fields with sub-cycle time resolution could provide new insight into attosecond electron dynamics. We describe an experimental setup for field sampling of degenerate four-wave mixing near infrared signals in the sub-cycle regime generated in solid and molecular targets. A femtosecond laser is centered at 800 nm which is later split into a gate beam and probe beam to focus into the target. The nonlinear signal electric field is completely measured using a field-sampling setup based on reflectivity modulation.