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Back Cover: The generation of amplifi ed spontaneous emission in high‐power CPA laser systems (Laser Photonics Rev. 10(2)/2016)
Publication year - 2016
Publication title -
laser and photonics reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.778
H-Index - 116
eISSN - 1863-8899
pISSN - 1863-8880
DOI - 10.1002/lpor.201670028
Subject(s) - laser , photonics , laser power scaling , amplified spontaneous emission , physics , optoelectronics , optics , active laser medium , laser science
This is a view into the 4th amplifier of the high‐power CPA laser system POLARIS. The excited laser material in the center is surrounded by the final lens array for focussing the diode pump beams into the laser medium. Spontaneous emission around the central laser wavelength of 1030 nm is generated in the active medium. Contamination of the medium with other rare‐earth ions induces parasitic up‐conversion, which leads to the blueish emission visible in the center. The generation and further amplification (amplified spontaneous emission, ASE) of this radiation in the near infrared leads to a drastic deterioration of the temporal intensity contrast of the laser system, which is an important parameter in experiments on high‐intensity laser‐matter interactions. Irradiation of the target by ASE prior to the main pulse can alter the target conditions significantly. This can even render the desired interaction, e.g. the acceleration of charged particles, impossible. Due to the ongoing development of high‐power laser systems to reach higher on‐target intensities a comprehensive understanding of the ASE generation process is crucial. (Picture: Sebastian Keppler et al., 10.1002/lpor.201500186 pp. 264–277, in this issue)