Surface plasmon induced spot and line formation at interfaces of ITO coated LiNbO3 slabs and gigantic nonlinearity

Zuoren Xiong,Hua Zhao,Xinyan Ma,Yingbin Zhang,Yanbo Pei

doi:10.1038/s41598-021-99270-4

Abstract

Remarkable spots and lines were clearly observed at the two interfaces of indium-tin-oxide coated Z-cut Fe-doped lithium noibate plates under illumination by milliwatt continuous-wave laser light; this occurred because of the visible surface plasmons (SPs) supported by the promising non-metal plasmonic system. The intriguing observations are here explained via the SP-strengthened nonlinear effect, through consideration of the electrostatic field (which is comparable to the atomic field) and its large gradient; this hints at a promising, highly sensitive plasmonic system. The gigantic nonlinear effect discussed in this paper should be ubiquitously existed in many oxide ferroelectric/semiconductor combinations and is promising for visible plasmonic applications.

Highlights

Remarkable spots and lines were clearly observed at the two interfaces of indium-tin-oxide coated Z-cut Fe-doped lithium noibate plates under illumination by milliwatt continuous-wave laser light; this occurred because of the visible surface plasmons (SPs) supported by the promising non-metal plasmonic system
Plasmonics is a well-established, rapidly expanding field that has stimulated the development of a variety of exotic devices and concepts, owing to the confinement of electromagnetic energy associated with the evanescent nature of surface plasmons (SPs)[1,2,3,4]
To study the influence of SPs on the nonlinearity of optical materials and tailor their optical responses, indium-tin-oxide (ITO) films were deposited onto slabs of Fe-doped lithium noibate (Fe:LiNbO3; Fe:LN) synthetic crystals; these are among the most investigated and commercially popular nonlinear optical materials, and they continue to attract considerable a ttention[13]