The
experiments that are most frequently run for our recent research
endeavors are TRIVE-FWM experiments. We use a regenerative
amplifier to pump two optical parametric amplifiers, which can be tuned
independently to pulse wavelengths throughout the mid-IR (giving the
first two variables). The output from one OPA is split
further, and each pulse train is passed into a retroreflector on a
movable stage. Actuators controlling the positions of these
stages allow us to adjust the time interval between each of the pulses
from the split OPA (shown as ω2
and ω2'
below) and
the pulses from the other OPA (ω1).
These delay times give experiments two more dimensions.
These three pulses are then spacially and temporally
overlapped in the sample. Please see the corresponding animation on the Animations page
for a demonstration of this process. The TRIVE signal (shown
below in red, and shown as a white pulse in the animation) is
then emitted in the direction determined by phase-matching and passed
through a monochrometer (another variable) to an MCT detector.
Spectra collected are slices in the 5D space of these
variables. We recommend looking into some of the recent publications
if you are interested in some of the explorations we have made.
