  A novel fabrication method for soft x-ray transmission grating and other
optical elements is presented. The method uses Focused-Ion-Beam (FIB)
technology to fabricate high-quality free standing grating bars on Transmission
Electron Microscopy grids (TEM-grid). High quality transmission gratings are
obtained with superb accuracy and versatility. Using these gratings and
back-illuminated CCD camera, absolutely calibrated x-ray spectra can be
acquired for soft x-ray source diagnostics in the 100-3000 eV spectral range.
Double grating combinations of identical or different parameters are easily
fabricated, allowing advanced one-shot application of transmission grating
spectroscopy. These applications include spectroscopy with different spectral
resolutions, bandwidths, dynamic ranges, and may serve for identification of
high-order contribution, and spectral calibrations of various x-ray optical
elements.
