Optical layouts for large infrared beamline opening angles

The number of infrared beamlines at synchrotron facilities is expending worldwide. Due to the long wavelength of the radiation in the infrared region, the optimum collection of the emitted photons requires large opening angles, both vertically and horizontally (order of few tens of mrad). Most of the infrared beamlines use toroid shaped mirrors, or elliptical mirror to conjointly focus both the vertical and the horizontal source emission. However, such optical set ups produce distorted images due to the optical aberrations produced by the depth and the circular shape of the source. In this article, we propose a new optical layout consisting in two optimized shape mirrors, focusing independently the vertical and the horizontal source emission, and providing low aberration beams for large horizontal apertures. The setup has been used to design the new LNLS Brazilian synchrotron Infrared beamline.