Lensless optics is a computer technology for object image acquisition without using any optical devices (lenses). Algorithms, existing to date, allowed working only with radiation, propagation perpendicularly to an object of interest.

A technology, known as reflective microscopy, is especially useful for working in soft X-ray radiation range, in which laboratory X-ray lasers and free-electron lasers already work. Researchers from the laboratory of X-ray optics of the Lebedev Institute of Physics currently search for solutions for a parabolic equation with initial conditions, preset on surfaces of various forms and orientations. The result of this work is an exact formula, which generalizes a famous Fresnel integral and helps solve abovementioned problem under conditions, when radiation propagates in no specific direction towards an object. This formula helped researchers develop computer software, which is a major tool for a new lensless technology of image monitoring.

Physicists have already developed an improved version of the software, which within permissible approximations of a parabolic equation can define radiation emission fields of non-planar objects with extremely high accuracy. Results, obtained by means of the new software, are expected to expand a field of real and numerical experiments with laser radiation.

 

 

Those, working in the field of X-ray optics, know that they would mainly deal with small-angle reflections. However, existing technique for imaging by means of wave phase reconstruction has been developed for geometry of normal incidence of a beam on a transparent object. It is obvious that such a complicated task, as identification of surface configuration by means of an existing technique of wave phase reconstruction. Research fellows from the laboratory of X-ray optics of the Lebedev Institute of Physics have concentrated their efforts on finding a solution for the abovementioned problem.

“That’s very strange that no one has ever tried to find a solution for this problem”, a research fellow and PhD in physics from the laboratory says. In case of successful solving the technique will be extremely useful for everyone, dealing with X-ray optics. During working on the problem, researchers have discovered some interesting analytical details, for instance, they found that scaling of Fresnel integral is not the only thing required for solution development.

Results, which Russian researchers have obtained, will be used for controlling X-ray mirrors in an ambitious international project XFEL. This a project on building an X-ray laser on free electrons. The principle of a free-electron laser is briefly following – electrons are first brought to high energies in a superconducting accelerator. They then fly on a slalom course through a special arrangement of magnets (the "undulator"), in which they emit laserlike flashes of radiation. The XFEL project is located in Germany.