Near-field optical study of the third-order nonlinear properties of polycrystalline silicon

Citation
Y. Choi et al., Near-field optical study of the third-order nonlinear properties of polycrystalline silicon, J KOR PHYS, 37(5), 2000, pp. 688-692
Citations number
10
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
JOURNAL OF THE KOREAN PHYSICAL SOCIETY
ISSN journal
0374-4884 → ACNP
Volume
37
Issue
5
Year of publication
2000
Part
2
Pages
688 - 692
Database
ISI
SICI code
0374-4884(200011)37:5<688:NOSOTT>2.0.ZU;2-K
Abstract
A near-field z-scan, which directly measures the beam spot size in thin fil ms, was done to examine the self-focusing effect near the diffraction limit in polycrystalline silicon by using a scanning fiber probe-tip. The polycr ystalline silicon showed both reverse-saturation (Im chi ((3)) approximate to 8 X 10(-3) esu) and self-focusing (Re chi ((3)) approximate to 2 X 10(-2 ) esu), as measured by using the conventional z-scan method. These results were compared with the beam spot size directly determined from the near-hel d z-scan measurements. The present input beam intensity dependence of the b eam spot size revealed that the beam radius became smaller with increasing input laser intensity, indicating that self-focusing effect in polycrystall ine silicon was dominant over reverse saturation at high laser beam intensi ty.