Nonlinear optics electromagnetic second-order

Nonlinear Optical Applications. Second-order nonlinear (NLO) materials based on ElAPs have shown promise for use in the photonics industry extensive research has been conducted in this area over the past several decades (356,357). Devices based on poly(diacetylene) have been used to demonstrate all-optical switching at 1.6 tm (358). The NLO process occurs when an electromagnetic field interacts with a medium. When the medium is subjected to an electric field E(0) and an optical field E(co), the nonlinear effect arises from field-induced... 

In order to describe the second-order nonlinear response from the interface of two centrosynnnetric media, the material system may be divided into tlnee regions the interface and the two bulk media. The interface is defined to be the transitional zone where the material properties—such as the electronic structure or molecular orientation of adsorbates—or the electromagnetic fields differ appreciably from the two bulk media. For most systems, this region occurs over a length scale of only a few Angstroms. With respect to the optical radiation, we can thus treat the nonlinearity of the interface as localized to a sheet of polarization. Fonnally, we can describe this sheet by a nonlinear dipole moment per unit area, -P ", which is related to a second-order bulk polarization by hy P - lx, y,r) = y. Flere z is the surface nonnal direction, and the... 

Heinz T F 1991 Second-order nonlinear optical effects at surfaces and interfaces Nonlinear Surface Electromagnetic Phenomena ed H-E Ponath and G I Stegeman (Amsterdam North-Holland) pp 353-416... 

T.F. Heinz, Second-Order Nonlinear Optical Effects at Surfaces and Interfaces in Nonlinear Surface Electromagnetic Phenomena, H.-E. Ponath, G. I. Stegeman (Eds.), North-Holland, Amsterdam, 1991. 

Problem 6.5. An electromagnetic wave hits a metal surface and generates a second-order nonlinear optical signal. What is the typical thickness of the surface layer that contributes to the signal and which physical effect is of the main importance in determining this length scale ... 

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