[seminar] Seminar na IF-u u utorak 25.09.2018. u 15:00h - dr. Oleg A. Louchev (RIKEN)

[Damir Staresinic]

Institut za fiziku, Bijenička cesta 46, 

predavaonica u zgradi Mladen Paić utorak, 25. rujna 2018., u 15:00 sati 
Laser-Matter Interaction in Dielectrics: Insights from Pulsed Second-Harmonic Generation in Periodically Poled LiTaO 3 
dr. Oleg A. Louchev 
RIKEN Center for Advanced Photonics, Wako, Saitama, Japan 



This presentation focuses on theoretical and experimental studies of laser second harmonic generation (SHG) in periodically-poled crystals in the range from ns to ps pulse duration. High-intensity and high-efficient SHG operation is inhibited by many side effects associated with dephasing of the involved lased waves caused by generation of non-uniform temperature distributions and plasma generation along the beam propagation. Generation of free electrons by generated second harmonic and accelerated to a high energy by generated pyro-electric field is shown to be able to produce high-density defects and damage in the rear side of the operating crystals. Temperature-controlled experimental study of high-intensity high- frequency ps SHG allowed to find the temperature effect of a single ps pulse. The detailed analysis of the plasma generation kinetics and related recombination pathways related to this experiment allowed to suggest a new modification of the non-equilibrium two-temperature model of short-pulsed laser-matter interaction leading to an excellent agreement with the experiment. This modification is valid for a wide range of laser-matter interactions and related application for operation and processing of dielectric materials for electron density below 10 21 cm -3 . Finally, we suggest a new scaling estimate for the characteristic time of electron-lattice energy transfer time agreeing well with experimental data for a wide range of materials. 


Voditelji seminara IF-a: [ mailto:hrvoje at ifs.hr | Hrvoje Skenderović ] i [ mailto:damirs at ifs.hr | Damir Starešinić ] 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.phy.pmf.unizg.hr/pipermail/seminar/attachments/20180918/20088fbd/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: logo_IF_seminar.jpg
Type: image/jpeg
Size: 9859 bytes
Desc: not available
URL: <http://www.phy.pmf.unizg.hr/pipermail/seminar/attachments/20180918/20088fbd/attachment.jpg>