Ultrarövid lézerimpulzus technológia: 80 MHz-es impulzusok erősítése

Andrásik, Attila: Ultrarövid lézerimpulzus technológia: 80 MHz-es impulzusok erősítése. Móra Akadémia, (4). pp. 13-23. (2017)

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Abstract

Ultrashort laser pulse technology: amplification of 80 MHz laser pulses : Many biological, medical, industrial, and scientific applications demand ultrashort laser pulses both with multi-MHz repetition rate and pulse energy at few tens of nJ. The temporal contrast of high intensity broadband lasers critically depends on the energy of the seed lasers. Combination of both demands motivates us to develop an amplifier system to boost the energy of few cycle laser pulses. The earlier attempts based on CW pump lasers have established a gain of 2–4. The core element of our designs is the recent availability of 80 MHz picosecond lasers. Here we present two operating amplifier systems for few cycle pulses, a NOPA designed to 80 MHz repetition rate, and a cryogenically cooled Ti:S based system at 80 MHz repetition rate, both designed to be tunable between 700–900 nm. One of the main challenges regarding the MHz repetition rate Ti:S amplifier system is to achieve high overall gain with a pump laser of high average power (15W) but as small pulse energy as half a µJ. Tight focusing is needed to reach the required fluence in the crystal, while such point-like high thermal load calls for cryogenic cooling of the crystal, which is bulky and hence poses a limit on the number of passes of the amplification. To reach a considerably high gain, we modeled, optimized, and experimentally realized a compact, astigmatismcompensated multipass amplifier with tightly focused pump and seed pulses. The beam diameters at each passes were measured with the knife - edge method. Using the novel multipass setup, a total gain of 2.1 was performed after 3 pass at the pump power of 15 W, which can be tuned between the 700–900 nm spectral range.

Item Type: Article
Journal or Publication Title: Móra Akadémia
Date: 2017
Volume: 4
Page Range: pp. 13-23
ISSN: 2064-809X
Uncontrolled Keywords: Lézerfizika, Lézertechnika
Additional Information: Bibliogr.: 22. p. ; Összefoglalás angol nyelven
Date Deposited: 2018. Jul. 10. 08:48
Last Modified: 2018. Jul. 26. 13:31
URI: http://acta.bibl.u-szeged.hu/id/eprint/53800

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