Abstract: A diffractor for electromagnetic radiation is based on a pseudo-spherical stepped geometry designed under the constant step width conditions. The diffractor consists of a few small pseudo-spherical curved dispersive elements (oriented crystal surfaces or gratings) that are located on a focal circle. The location on the focal circle of each element is made to guarantee the same Bragg angle for the incident radiation. Thus a diffractor is an array of diffracting elements (“steps”), each one contributing to the total solid angle of the diffractor, that increase the spectral output of the device without decreasing the resolution.

Abstract: A diffractor for electromagnetic radiation with a spherical stepped geometry constructed under the constant step width conditions (here defined as pseudo-spherical geometry). The diffractor consists of a plurality of spherically curved dispersive elements (oriented monocrystals, crystal surfaces or gratings) that are located on a focal circle. The location on the focal circle of each element is made to guarantee the same Bragg angle for the incident radiation. Thus a diffractor is an array of diffracting elements (“steps”) each one contributing to the total solid angle of the diffractor, that increase the spectral output of the device without decreasing the resolution. Because the steps are spherically curved, they are curved also in the direction perpendicular to the focal circle in order to satisfy Bragg's law for diffraction over a maximum area of the diffractor.