Title :
Photorefractive diffusion-driven self-focusing and self-trapping in near-transition paraelectric crystals
Author :
Crosignani, Bruno ; DelRe, Eugenio ; Porto, Paolo Di ; Tamburrini, Mario ; Degasperis, Antonio ; Agranat, Aharon ; Segev, Mordechai
Author_Institution :
Dipt. di Fisica, l´´Aquila Univ., Italy
Abstract :
Reports on the observation of self-focusing and self-trapping in K 1-yLiyTa1-xNbxO3 (KLTN) in the very-near-transition paraelectric phase without any external applied field and without any sort of artificial background illumination. We show that this behavior depends only on the temperature T of the sample and is independent of beam intensity and beam size. In order to explain this peculiar phenomenon we make use of the PR paraelectric diffusion nonlinearity, obtaining solutions that describe self-focusing and that eventually lead to the formation of `diffusion-driven solitons´
Keywords :
ferroelectric materials; ferroelectric transitions; lithium compounds; optical self-focusing; optical solitons; photorefractive materials; potassium compounds; tantalum compounds; K1-yLiyTa1-xNbxO 3; KLiTaO3NbO3; artificial background illumination; beam intensity; beam size; diffusion-driven solitons; near-transition paraelectric crystals; paraelectric diffusion nonlinearity; photorefractive diffusion-driven self-focusing; photorefractive diffusion-driven self-trapping; self-focusing; self-trapping; temperature; very-near-transition paraelectric phase; Crystals; Diffraction; Focusing; Laser beams; Lighting; Optical beams; Optical propagation; Optical refraction; Photorefractive effect; Solitons;
Conference_Titel :
Nonlinear Optics '98: Materials, Fundamentals and Applications Topical Meeting
Conference_Location :
Kauai, HI
Print_ISBN :
0-7803-4950-4
DOI :
10.1109/NLO.1998.710337
