Testing the setup

First steps towards EUV transient grating: testing the setup in the laser lab! 

The main experimental hurdle for FEL-based TG is to transpose the conventional optical layout into the EUV/soft X-ray range. The lack of reliably transmission optics in this wavelength range (1-100 nm) prevents the use of diffractive optical elements (phase masks) and achromatic doublets, that are at the basis of optical setups. Moreover, the lack of phase masks makes quite challenging the implementation of heterodyne detection, which greatly improve many aspects of the experiments. We tested various options at the EIS-TIMER laser laboratory and we evaluated that an "all-reflective" optical layout (top panel) is the best compromise for an FEL-based instrument; please note that the trasmission optics used for second harmonic (SH) generation are is not needed with the FEL.