A microscope without a lens

It is known since a long time that x-rays, which are nothing but light of very short wave length, can be used for microscopy. This is particularly attractive because due to the small wave length x-rays allow studying objects which are invisibly small in an optical microscope. Here we present a truly new kind of x-ray microscope, one which does not need lenses and can nevertheless investigate objects of arbitrary size. This so called ptychographic microscope needs coherent (laser-like) x-rays from a defined source and produces an interference pattern on a CCD camera. Translating the sample and then stitching together many such interference patterns allows to easily reconstruct the object which produced the diffraction pattern. Although similar techniques were known, this technique is new since it needs no lens, can image objects which attenuate the x-rays and shift their phase, and can image arbitrarily large objects. Furthermore the reconstruction in the computer is significantly faster, simple and unambiguous. A real breakthrough in microscopy accomplished without using a single lens.

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