ELI-HU Research and Development Non-Profit Limited Liability Company The Extreme Light Infrastructure (ELI) project is an integral part of the European plan to build the next generation of large research facilities identified and selected by the European Strategy Forum on Research Infrastructures. ELI will be the first infrastructure in the world to enable the investigation of the interaction between matter and light at the highest intensity, in the so-called ultra-relativistic range. It will open a doorway into new territories within physics and new technical developments. The main objective of ELI Attosecond Light Pulse Source (ELI ALPS) is to establish a unique attosecond facility in Szeged, Hungary which provides developers and users with light sources within the THz (1012 Hz) to x-ray (1018-1019 Hz) frequency range in the form of ultrashort pulses at high repetition rate.