Abstract- Possibility of high-energy THz generation in LiTaO3

L. Tokodi, A. Buzády, J. Hebling, L. Pálfalvi,

http://link.springer.com/article/10.1007/s00340-016-6513-x

Due to the absence of the detrimental three-photon absorption, LiTaO3 is a promising crystal for terahertz generation when pumping with an 800-nm pump wavelength. The nonlinear optical, photorefractive and dielectric (except the bandwidth) properties at the optical and the terahertz wavelength are very similar to those of LiNbO3. The absorption coefficient and refractive index spectra of 1 mol% Mg-doped stoichiometric LiTaO3 measured by terahertz time domain spectroscopy are presented. Optimization calculations have been performed, and results for a hybrid-type high-energy terahertz source using LiTaO3 are presented. About 90 % diffraction efficiency is predicted with a practically feasible contact grating.

Abstract-Hybrid tilted-pulse-front excitation scheme for efficient generation of high-energy terahertz pulses

L. Pálfalvi, Z. Ollmann, L. Tokodi, and J. Hebling
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-24-8-8156

Conception of a hybrid type tilted-pulse-front pumping scheme for the generation of high-energy terahertz pulses is presented. The proposed setup is the combination of the conventional setup containing imaging optics and the contact grating. The solution was developed for nonlinear materials requiring large pulse-front-tilt angle, like LiNbO3. Due to the creation of the pulse-front-tilt in two steps the limitations of imaging errors can be significantly reduced. Furthermore the necessary grating constant of the contact grating can be larger compared to the simple contact grating scheme making possible the fabrication of the grating profile with significantly higher precision. A detailed optimization procedure with respect to the diffraction efficiency on the contact grating is given for LiNbO3. Instructions are also given how to construct the geometry of the setup in order to minimize imaging errors. Examples are given for LiNbO3 based practically realizable, optimized schemes with reduced imaging errors and high diffraction efficiency on the contact grating.

© 2016 Optical Society of America

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Abstract-Hybrid tilted-pulse-front excitation scheme for efficient generation of high-energy terahertz pulses

L. Pálfalvi,1,* Z. Ollmann,1,2 L. Tokodi,1 and J. Hebling1,2,3 

1Institute of Physics, University of Pécs, Ifjúság ú. 6, 7624 Pécs, Hungary
2Szentágothai Research Centre, University of Pécs, Ifjúság ú. 20, 7624 Pécs, Hungary 3MTA-PTE High-Field Terahertz Research Group, University of Pécs, Ifjúság ú. 6, 7624 Pécs, Hungary *palfalvi@fizika.ttk.pte.hu 

https://www.osapublishing.org/DirectPDFAccess/679F1BB3-96C9-FEBF-9D4708D5CB3C835B_338821/oe-24-8-8156.pdf?da=1&id=338821&seq=0&mobile=yes

Abstract: Conception of a hybrid type tilted-pulse-front pumping scheme for the generation of high-energy terahertz pulses is presented. The proposed setup is the combination of the conventional setup containing imaging optics and the contact grating. The solution was developed for nonlinear materials requiring large pulse-front-tilt angle, like LiNbO3. Due to the creation of the pulse-front-tilt in two steps the limitations of imaging errors can be significantly reduced. Furthermore the necessary grating constant of the contact grating can be larger compared to the simple contact grating scheme making possible the fabrication of the grating profile with significantly higher precision. A detailed optimization procedure with respect to the diffraction efficiency on the contact grating is given for LiNbO3. Instructions are also given how to construct the geometry of the setup in order to minimize imaging errors. Examples are given for LiNbO3 based practically realizable, optimized schemes with reduced imaging errors and high diffraction efficiency on the contact grating.