Traditional transmissive polarimetric methods can be used for wavelengths above 123 nm where birefringent materials transmit light and create significant birefringence. Below 123 nm, no suitable solution is known to measure the four Stokes parameters on a large wavelength range. Therefore, we study here an innovative reflective (rather than transmissive) polarimeter working in the far ultraviolet (FUV) range from 90 to 130 nm. We take advantage of the phase shift created by reflections as well as the different reflectivities for p (orthogonal ⊥) and s (parallel ∥ to the plane of incidence) polarizations to design an FUV polarimeter. Simulation of the analyzer and modulator using Mueller matrices coupled to polarimetric efficiencies calculations allowed optimization of reflective polarimeters for the first time, to the best of our knowledge. This opens up a new perspective for FUV polarimetry below 123 nm.