Patent Number: 
Section: abstract

An X-ray waveguide which: shows a small propagation loss of an X-ray; does not deteriorate owing to oxidation; and can be easily produced is realized with an X-ray waveguide, including: a core for guiding an X-ray in such a wavelength band that the real part of refractive index of materials is 1 or less; and a cladding for confining the X-ray in the core, in which: the cladding has a one-dimensional periodic structure consisting of at least two materials having different real parts of refractive index; one of the materials is inorganic one, and another one of materials is any of an organic material, a gas, or vacuum; and the core and the cladding are formed so that the critical angle for total reflection at the interface between the core and the cladding is smaller than a Bragg angle depending on the periodicity of the one-dimensional periodic structure.