Polaris (laser)

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View into the control room of the POLARIS laser system

POLARIS - P etawatt O ptical L aser A mplifier for R adiation I ntensive Experiment S is a high-power laser and a joint research project between the Physics and Astronomy Faculty at the University of Jena and the Helmholtz Institute Jena (HI-Jena).

POLARIS is the world's only completely diode- pumped laser system that can generate peak pulse powers of 200 TW and can be used for experiments with high intensities. In particular, experiments on laser particle acceleration are carried out with POLARIS at HI-Jena.

construction

  • Front-end laboratory

  • Look into the extensor

  • The third amplifier

  • The fourth amplifier

  • Gain medium

  • Sketch of the fifth amplifier

  • Compressor Laboratory

  • Target laboratory

The laser system is set up on a laboratory area of ​​250 m² in total. Here the laser pulses are generated in an oscillator, stretched over time, then amplified in their energy by more than 10 orders of magnitude and finally compressed again over time. They are then focused in the experiment area with a parabolic mirror so that they are then available for high-intensity experiments.

In order to be able to efficiently amplify the pulses with a pulse duration of 100 fs, POLARIS is based on the principle of chirped pulse amplification ( CPA ). In addition to five laser amplifiers, it has a Strecker compressor system with the special feature of a so-called mosaic grid compressor. Ytterbium-doped fluoride-phosphate glass and CaF 2 , which is pumped through high-performance laser diodes with a wavelength of 940 nm, are used as the active medium . The glass was specially developed for POLARIS by the Otto Schott Institute in Jena. POLARIS generates laser pulses with a central wavelength of 1030 nm and a bandwidth of 19 nm ( FWHM ). In order to be able to cool the active medium efficiently between the individual pulses, the laser pulses are generated with a repetition rate of 1/50 Hz.

POLARIS can currently generate laser pulses with a pulse energy of 54 J in front of the compressor. After the compressor, laser pulses with more than 17 J pulse energy and a pulse duration of less than 100 fs are routinely used in the experiment.

By using adaptive optics, the intensities in the focus reach the order of magnitude of 10 21  W / cm 2 . The time intensity contrast of the laser pulses is currently up to 10 −13 for the amplified spontaneous emission (ASE). The temporal intensity contrast, which is very important for successful experiments on particle acceleration, is, as well as increasing the available pulse energy, an essential part of the further development of the laser system.

See also

Web links

Commons : POLARIS  - collection of images, videos and audio files

literature

  • A. Kessler et al. a .: 16.6 J chirped femtosecond laser pulses from a diode-pumped Yb: CaF2 amplifier In: Optics Letters Vol. 39, Issue 6, pp. 1333-1336 (2014), doi: 10.1364 / OL.39.001333
  • M. Hornung et al. a .: High-intensity, high-contrast laser pulses generated from the fully diode-pumped Yb: glass laser system POLARIS In: Optics Letters Vol. 38, Issue 5, pp. 718-720 (2013), doi: 10.1364 / OL.38.000718
  • M. Hornung et al. a .: The all-diode-pumped laser system POLARIS - an experimentalist's tool generating ultra-high contrast pulses with high energy In: High Power Laser Science and Engineering Volume 2/2014, e20, doi: 10.1017 / hpl.2014.26
  • J. Hein et al. a .: POLARIS: An All Diode-Pumped Ultrahigh Peak Power Laser for High Repetition Rates In: Lasers and Nuclei: Applications of Ultrahigh Intensity Lasers in Nuclear Science , Ed .: Heinrich Schwoerer, Joseph Magill, Burgard Beleites, pp. 47-66

Individual evidence

  1. ^ Helmholtz Institute Jena: POLARIS Laser - Helmholtz Institute Jena. (No longer available online.) In: www.hi-jena.de. Archived from the original on April 26, 2016 ; Retrieved April 26, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.hi-jena.de
  2. ↑ Donna Strickland , Gérard Mourou : Compression of amplified chirped optical pulses . In: Optics Communications . tape 56 , no. 3 , December 1, 1985, pp. 219-221 , doi : 10.1016 / 0030-4018 (85) 90120-8 (English).
  3. ↑ M. Hornung: Mosaic grid compressor for femtosecond laser pulses of high energy . Dissertation. Der Andere Verlag, 2010, ISBN 978-3-86247-067-9 .
  4. ↑ Marco Hornung, Hartmut Liebetrau, Sebastian Keppler, Alexander Kessler, Marco Hellwing: 54 J pulses with 18 m bandwidth from a diode-pumped chirped-pulse amplification laser system . In: Optics Letters . tape 41 , no. 22 , 15 November 2016, ISSN  1539-4794 , doi : 10.1364 / ol.41.005413 (English).
  5. ↑ Hartmut Liebetrau, Marco Hornung, Andreas Seidel, Marco Hellwing, Alexander Kessler: Ultra-high contrast frontend for high peak power fs-lasers at 1030 nm . In: Optics Express . tape 22 , no. 20 , October 6, 2014, ISSN  1094-4087 , doi : 10.1364 / oe.22.024776 (English).

Coordinates: 50 ° 56 ′ 4.4 "  N , 11 ° 34 ′ 50.7"  E