The short-pulse amplification in the L1 and L2 systems will be based on optical parametric chirped pulse amplification (OPCPA). The L3 system will use a titanium-doped sapphire power amplifier. L4 will employ OPCPA preamplifiers that provide multi-joule seed pulses for final amplification to the kJ level in neodymium (Nd)-doped glass.
The DPSSL pump technology in L1 and also in the broadband front end of L2 is based on Ytterbium-doped yttrium aluminum garnet (Yb:YAG) thin-disk technology operating at 1 kHz. The DPSSL pump engine for L2 exploits Yb-doped YAG, gas cooled to ~150 K, as an active medium. The DPSSL pump engine for L3 is based on Nd-doped glass operating at room temperature.
The facility will make available high-brightness, multi-TW, ultrashort laser pulses at kHz repetition rates, PW laser pulses with 10 Hz repetition rate and kJ nanosecond laser pulses for generation of 10 PW peak power. These systems will allow the facility to meet the requirements of the international user community for cutting-edge laser resources for programmatic research in generation and applications of high-intensity X-ray sources, in particle acceleration, and in dense-plasma and high-field frontier physics.
The L1 laser is being developed in house by the ELI-Beamlines laser team. The laser system is designed to generate <20 fs pulses with energy exceeding 100 mJ per pulse at a high repetition rate (1 kHz). The concept of the laser is based entirely on amplification of frequency chirped picosecond pulses in an optical parametric chirped pulse amplification (OPCPA) chain consisting of a total of seven amplifiers. The OPCPA amplifier stages are pumped by precisely synchronized picosecond pulses generated by state-of-the-art thin-disk-based Yb:YAG laser systems.
The L2 beam line is a laser system designed to generate ultrashort laser pulses with peak power reaching 1 PW (1 petawatt = 1,000,000,000,000,000 watts). The laser will be able to operate at a high repetition rate of 10Hz due to the full utilization of new technologies such as laser diode pumping and cryogenic cooling of the laser material. The main amplifiers are based entirely on optical parametric chirped pulse amlification (OPCPA), allowing for extremely short pulses with durations below 15 fs to be generated.
The L3 laser system called HAPLS (The High-Repetition-Rate Advanced Petawatt Laser System) is designed to deliver PW pulses with energy of at least 30 J and durations <30 fs, at a repetition rate of 10 Hz. This system was developed at the Lawrence Livermore National Laboratory, with ELI-Beamlines cooperating on the development of the PW pulse compressor, the short-pulse diagnostics, and the short-pulse part controls and timing.
The L4 beam line is designed to generate an extremely high and unprecedented peak power of 10 PW (Petawatt) during pulse duration of about 130 fs. The uncompressed energy can reach almost 2 kJ with a shot rate of 1/min, which is a major step in the field of kJ-class lasers. The architecture is based on direct compression of a broadband beam amplified by a combination of different Nd:glass slabs.
The most important activity in the ELI-Beamlines project is the development of new laser technologies. This includes, for example, developing new techniques for growing laser crystals, new solutions for the cryogenic cooling of high-power repetition rate laser amplifiers, new techniques for femtosecond synchronization of laser pulses, advanced repetition rate diagnostics of femtosecond pulses, advanced control systems, and developing innovative solutions for petawatt (PW) pulse compressors. Some of these activities are carried out in cooperation with industry.