A unique optical parametric chirped-pulse amplification (OPCPA) laser system, providing 5 terawatts of output power at a 1-kHz repetition rate, has been produced by a consortium led by Ekspla UAB and Light Conversion UAB. The Sylos 1 system was designed and built for the Extreme Light Infrastructure Attosecond Light Pulse Source (ELI-ALPS) facility in Szeged, Hungary. The main objective of the project is to create a unique European research center that will provide the international research community with laser sources and pulses. The Szeged facility aims to produce the highest intensity laser pulses in the world with the highest repetition rates and shortest pulses. 5 TW laser system produced by the Ekspla- and Light Conversion-led consortium. Courtesy of Ekspla. “This system is unique due to its outstanding combination of power and pulse duration,” said Kestutis Jasiunas, CEO of Ekspla. “Five terawatts establishes Sylos as one of the most powerful systems in the world, generating 10 fs or shorter pulses at [a] 1-kHz repetition rate. Secondly, it employs innovative OPCPA technology born and perfected at Vilnius University [in] Lithuania. Featuring comparatively simple and cost-effective layout, OPCPA is a key approach in equipping the high-intensity laser facility to reach attoseconds in deep UV regions.” The system consists of the Pharod industrial-grade femtosecond laser, a specially designed diode-pumped Nd:YAG picosecond pump laser and four picosecond OPCPA stages, preceded by a seed pulse stretcher and followed by a compressor. “To the best of our knowledge, Sylos 1 delivers the highest average power currently achieved among carrier-envelope-phase-stabilized, few-cycle, terawatt-class laser systems,” said Gediminas Veitas, project leader at Light Conversion.