CdTe/CZT based spectroscopic two-dimensional (2D)/three-dimensional (3D) imagers when operated in the Compton regime can work as high performance scattering polarimeters, for high-energy astrophysics. Polarimetry in high-energy astrophysics has been little explored. To date, X-and γ-ray source emissions have been studied almost exclusively through spectral, imaging, and timing analysis. Polarization measurements provide two additional observational parameters: the polarization angle and the level of linear polarization. These additional parameters should allow for a better discrimination between the physical mechanisms of different emission models characterizing a celestial object. Therefore, polarimetry will play a strategic role in new instrumentations for future high-energy astronomy missions. 2D and 3D CZT/CdTe spectroscopic imagers provided with coincidence readout logic can efficiently handle scattering events to perform simultaneously polarization, spectroscopy, imaging, and timing measurements. Herein, we describe the results obtained, both experimentally and by MC simulations, with CdTe/CZT pixel detector prototypes in high-energy polarimetry. We give an overview on the achievable polarimetric performance with spectroscopic imagers and on how these performances are affected by detector configuration parameters. Finally, we address the perspective of scattering polarimetry opened by the recent implementation of new high energy focusing optics, as broadband Laue lens, in next generation of hard X-and soft γ-ray astronomy instrumentation. The unprecedented sensitivity achievable by these telescopes will definitely open the window of polarimetry in this high-energy range.

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The hard X-/soft gamma-ray band is still not well explored in astrophysics in spite of several unanswered science questions that can only be settled in this energy band, such as the origin of the 511 keV positron annihilation line from the Galactic Center region. The main reason is that this band has been explored so far with non-focusing instruments, that can achieve a limited sensitivity and angular resolution. Our goal is the development of a focusing telescope based on a Laue lens made of bent crystals of Silicon and Germanium, that diffract photons in the 50-700 keV band, with unprecedented angular resolution and sensitivity to continuum spectrum and to lines. Here some result will be reported concerning the elastic bending of the crystals by pressing them on substrates with one of the two main surfaces worked in order to get the same curvature of the lens. This is achieved thanks to accurately anodic bonding them to these substrates, avoiding/without the use of glue, in such a way to satisfy the required angular orientation of the crystals in the lens.