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We present a novel technique to align a tiled grating in all five relevant degrees of freedom utilized in the compressor of the high-power chirped-pulse amplification laser system POLARIS at the Institute for Optics and Quantum Electronics, Jena, Germany. With this technique, alignment errors of the two gratings with respect to each other can be detected with an accuracy of 1 microrad for the rotational and 40 nm for the translational degrees of freedom. This is well sufficient to recompress 1030 nm pulses, which were stretched to 2.2 ns before amplification, to their bandwith limit of 150 fs.

the Institute of Optics and Quantum Electronics in Jena, Germany, the currently most powerful diode-pumped solid-state laser system with 25-TW peak power Polaris is in operation. In this paper we give an overview about the dispersion management of the chirped pulse amplification in order to minimize the pulse duration and thus to maximize the intensity available for experiments. A detailed description of the stretcher and compressor design with a novel alignment routine is given as well as measurements for the pulse duration and the temporal contrast. The far field measurement of the beam focussed by an off-axis parabola yields a nearly diffraction limited focal spot. [ABSTRACT FROM AUTHOR]

The generation of the highest laser peak intensities at a high degree of system compactness can be achieved by combining modern diode-pump technologies with the chirped pulse amplification technique. In principle, the spectroscopic properties of the gain medium determine the scaling laws of both high output pulse energy and short pulse duration. Here we introduce a novel criterion classifying laser materials with respect to their ability to generate pulses of highest peak power in a diode-pumped solid state laser system. Furthermore, amplified spontaneous emission as well as laser damage issues affecting the efficiency and compactness of a laser amplifier system are discussed. [ABSTRACT FROM AUTHOR]

Within the POLARIS project multi-pass amplification to the 10 joule level for a femtosecond CPA laser system has been achieved by diode-pumping an Yb3+ doped fluoride-phosphate glass disk with a total energy of 240 J. The collimated light of 40 diode stacks is focussed onto a circular area of the glass disk with a diameter of 18 mm. A two-sided ring shaped setup is used for axially symmetric pumping. We developed a computer aided optimization routine for the positioning of single pump foci to gain a smooth homogeneously distributed, top-hat shaped pump profile. The homogeneity of the pump light distribution was improved substantially by this new method. [ABSTRACT FROM AUTHOR]

A 5.3 W average output power at a pulse repetition-rate of 40 kHz was achieved with a diode-end-pumped Nd:YVO[sub 4] regenerative amplifier. In a continuous-wave operation an optical efficiency of 43% was reached. The output pulse duration is 19 ps, if seeded by a 7-ps-oscillator. A maximum pulse repetition-rate of 80 kHz and a maximum pulse energy of 350 μJ were generated by the entire laser system. [ABSTRACT FROM AUTHOR]