Kelių optinių ciklų trukmės impulsų parametrinis stiprinimas infraraudonojoje srityje /

Main objective of this thesis is to generate and amplify few cycle pulses in the infrared region. In this thesis, two approaches were introduced for few cycle pulse parametric amplification at 800 nm and 1.5 μm. First approach is dedicated for prospects for increasing average power of OPCPA via multi-beam pumping; the second approach is dedicated for generation of carrier-envelope-phase (CEP) stable high energy (up to tens of millijoules) few-cycle pulses at 1.5 μm. An experimental investigation of two or three beams-pumped OPCPA system based on type I BBO crystal is presented. The 2nd OPA stage was pumped by two or three pump beams derived from independent Nd:YAG laser amplifiers. The efficiency of interaction was shown to be comparable to that of single-beam pumped OPA and diminishes only slightly due to cascaded parametric diffraction of interacting waves. The effect was observed and its impact on efficiency of parametric amplification process was shown to decrease at larger intersecting angles of pump. In the prospect, the use of multiple lasers for OPA pumping has an appeal for increasing the repetition rate and consequently the average power of an ultrashort pulse laser system. Finally, the concept and realization of hybrid system based on type II KTP OPCPA and filamentation are described. A CEP-stable 1.5 μm OPCPA system with pulse energies up to 12.5 mJ after 4 OPA stages is demonstrated. Furthermore, self-compression of CEP-stable 2.2 mJ, 74.4 fs, 1.57 μm input pulses down to 19.8 fs duration in a single filament in argon gas is also demonstrated. We foresee that our sub-4 cycle pulse will open the door to new experiments in attosecond high-field science in the near future.

Grantor dc:publisher

Institutional Repository of Vilnius University

Year dc:date

2010

Author dc:creator

• Ališauskas, Skirmantas,

Contributors dc:contributor

• Smilgevičius, Valerijus

• Few-cycle pulses ; optical parametric amplification ; energy combining ; filamentation ; pulse self-compression

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

lit

Repository record dc:identifier

https://repository.vu.lt/VU:ELABAETD2011862&prefLang=en_US

OAI identifier oai:identifier

oai:vu.lt:elaba:2011862