Lasers of DGL

Prague Asterix Laser System (PALS)

The Prague Asterix Laser System facility is conceived as a laboratory providing the basis for experimental research in the field of high-power lasers and their applications, notably in the physics of laser plasmas.

The principal experimental resource at PALS is the high-power iodine laser system Asterix IV. This instrument was developed at the Max Planck Institute for Quantum Optics in Garching, Germany, and with the latest upgrade in 1991 it provided irradiation facility at the 1 kJ energy level until May 1997. It has been exploited by a wide international research community, within the European Large-Scale Facilities scheme.

The Czech Republic's Academy of Sciences has become the operator of the Asterix laser following an Euratom-assented agreement with the Max Planck Institute for Quantum Optics, signed in June 1997. The funding needed to construct the PALS facility integrating the Asterix laser was approved in December 1997. The construction of the PALS building was completed in March 1999, the installation and commissioning of the laser and of the target facilities in December 1999. Successful operational tests performed in the period November 1999–May 2000 were crowned by a festive launching of the completed laser system on June 8, 2000. The facility has been serving its users since September 2000. More information on www.pals.cas.cz.

COIL (Chemical Oxygen-Iodine Laser)

Staff: Jarmila Kodymova, Otomar Spalek, Vit Jirasek, Miroslav Censky.

SOFIA (solid-state oscillator for iodine amplifier)

Staff: Hana Turcicova, Petr Straka.

PERUN (Photodissociation Iodine Laser)

This laser system (called PERUN) is an iodine photodissociation laser chain of the master oscillator (MO) and four amplifiers (A₁-A₄) pumped by quartz Xe flashlamps.

The flashlamps, wich are powered from a condenser bank of 60 kJ, 5 keV, emit ultraviolet (UV) light in the 250–290 nm spectral band in 300 microseconds pulses (efficiency 5%). The UV photon splits the molecules of the laser gas (perfluorprophyliodide i-C₃F₇I) to produced iodine atoms in the first excited (fine structure) state I^*(5²P_1/2) with a 90% yield. The lasing at infrared (IR) wavelength 1.315 micrometers occurs between this level and the ground level I(5²P_3/2) of atomic iodine. The plug-to-light energy efficiency of the iodine laser system is less then 0.1%. It means that the laser produces pulses with energy of about 40 J.

Main characteristics are: pulse length (FWHM) of 300 ps, single beam diameter of 85 mm, divergence 4*10^-4 rad, contrast better than 10⁶, focus of 100 micrometers (f=20 cm), power density on the target 5*10¹⁴ W/cm², repetition rate of shot 15 min.

The laser system includes KD₂PO₄ crystals for a frequency conversion to the 2nd and 3rd harmonic frequences (wavelengths 658 nm and 440 nm) with 50% efficiency. There is a possibility of a illumination of a target by a double pulse with the prepulse being of varying colour, energy and time delay. The IR power left over, after the conversion, can be used for a two frame backlighting.