Optical unit and associated method

A method of manufacturing an optical assembly comprising a laterally graded reflective multilayer having a reflecting surface to reflect incident X-rays under low incidence angles while producing a two-dimensional optical effect, said reflecting surface comprising a single surface conformed along two curvatures corresponding to two different directions, the method comprising:

• providing a substrate having a curvature along a first direction;
• coating the substrate;
• and
• curving the substrate along a second direction different than the first direction;
• wherein one of the first or second directions is a sagital direction of the incident X-rays, and the curvature of the substrate corresponding to the sagital direction defines a radius of curvature which is less than 20 mm.

A device for generating and conditioning X-rays for analytical applications, the device comprising:

• a X-ray source operable to emit an X-ray beam;
• and
• an optical assembly coupled to the X-ray source, the assembly comprising a laterally graded reflective multilayer having a reflecting surface to reflect incident X-rays of the X-ray beam under low incidence angles while producing a two-dimensional optical effect, the reflecting surface comprising a single surface conformed along two curvatures corresponding to two different directions;
• wherein the two different directions correspond respectively to sagital and meridional directions of the incident X-rays, and the reflecting surface has a sagital curvature radius of less than 20 mm;
• and
• wherein the optical assembly is operable to focus the X-ray beam emitted by the X-ray source onto a focalization point having a distance less than 90 cm from the X-ray source.