He said the company was also developing a diffractive lens.

Physicists had always known about about diffractive lenses, of course, but in the lens industry it had been widely accepted for decades that diffraction would provide a distorted image, industry executives said.

If the X-ray source isn't collimated, as with a synchrotron radiation, elementary collimating mirrors or diffractive lenses are used in the place of the refractive lenses used in optics.