X-ray Optics:
X-ray optics is the branch of optics which manipulates x-rays instead of visible light. First proposed by M.A. Kumakhov, it was originally thought out as the reflection of x-rays from smooth surfaces. While lenses for visible light are made of a transparent material with an index of refraction substantially different from 1, there is no equivalent material for x-rays. Therefore, the only methods of x-ray manipulation are through reflection, diffraction and interference effects. Examples of technologies in use include zone plate and multilayer optics based systems and microstructured optical arrays.