What are you trying to image? Pinches are bright enough emitters that optical back-lighting is not necessary. Most back-lighting experiments must be in the x-ray regime (1-10 keV) so you can see through the pinch region and get the mass density.
Interferometry in the pinch region requires intense UV lasers at the low energy limit like more like soft x-ray lasers at 50-100 eV. As I recall, LPP is not a fan of interferometry techniques. Even if the wavelengths are correct, the time is so short/power so high you’d likely damage the detector. Most cutting edge plasma diagnostics are running with ~10 ps lasers which is more than enough. Most of us low-rent folks are using ~1 ns lasers for diagnostics before the pinch implodes to measure the plasma density and the local magnetic field.
Associated components like non-linear optics are interesting for pinch research but they need to be evolved substantially to ensure the measured signals are real representation of the data before the non-linear optics are used.