Quantum ghost polarimetry with entangled photons.

The theory of the formation of polarization ghost images in biphoton light of spontaneous parametric scattering is developed. On the basis of the developed theory, the quantum ghost polarimetry concept has been suggested, which makes it possible to obtain two-dimensional maps of the polarization properties of objects by measuring a set of correlation functions obtained in various polarization states of photons. For objects with linear dichroism, a complete set of measurement states is found, which allows for obtaining the maps of the distributions of absorption, value, and azimuth of anisotropy.

Ghost polarimetry with unpolarized pseudo-thermal light.

We present an experimental implementation of the ghost polarimetry concept in unpolarized light, which allows obtaining complete information on the spatial distribution of polarization properties of objects with linear dichroism. It is theoretically shown that it is possible to restore the spatial distribution of the azimuth and a value of anisotropy of such objects. The developed technique allows us to free up the object arm from all additional optical elements, including polarizers. The experimental results of measuring the dichroism parameters of a test four-sectional sample are presented, which demonstrate the efficiency of the method and confirm the correctness of the developed theoretical model.

Observation and theory of X-ray mirages.

The advent of X-ray lasers allowed the realization of compact coherent soft X-ray sources, thus opening the way to a wide range of applications. Here we report the observation of unexpected concentric rings in the far-field beam profile at the output of a two-stage plasma-based X-ray laser, which can be considered as the first manifestation of a mirage phenomenon in X-rays. We have developed a method of solving the Maxwell-Bloch equations for this problem, and find that the experimentally observed phenomenon is due to the emergence of X-ray mirages in the plasma amplifier, appearing as phase-matched coherent virtual point sources. The obtained results bring a new insight into the physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and open additional opportunities for X-ray plasma diagnostics and extreme ultraviolet lithography.