Band structure effects in surface second harmonic generation: The case of Cu(001)

Abstract

We have performed a study of simultaneous nonlinear optical second harmonic generation ͑SHG͒ and angle-resolved nonlinear photoemission at the Cu͑001͒ surface excited by fundamental photon energies near 3 eV. At these excitation energies, we identify a dominant contribution to the SHG signal that is determined by a two-photon resonance between the d bands and the n = 1 image-potential state at the Cu͑001͒ surface. The near-resonant behavior of SHG and nonlinear photoemission is studied via Cs adsorption, which allows to systematically lower the work function and thus the reference vacuum level of the image potential. Comparison of the angle-resolved photoemission signal, arising from a restricted region of electronic momentum space, with the simultaneous optical SHG signal allows to identify an additional contribution of electronic states with nonzero surface-parallel momentum to the SHG signal enhancements. A simple model accounting for the observed behavior is developed and the implications for the quantitative understanding of SHG are discussed.

Resonant coherent three-photon photoemission from Cu(001)

“…Such combined experiments can provide additional information about the optically excited system under investigation. 38 The numerical treatment of Eq. ͑5͒ is in principle straightforward.…”

Study of the interfacial array behaviour of surfactant at very low concentration by second harmonic generation and molecular dynamic simulation

“…Surfaces of different materials including metal, semiconductor and nonconductor were used to generate surface SHG radiation [12]. SHG study of surfactant solution can provide a lot of information about the properties of molecules at the interface, for example, the molecular second-order polarizability and information of the molecular ordering, symmetry, and orientation.…”

Surface second-harmonic generation based on periodically poled LiNbO 3 nonlinear optical crystal

“…[3] Thereafter, surfaces of many different materials such as metals, semiconductors, oxides and even liquids were used to generate surface SHG radiation. [4] At the same time the basic of surface nonlinear generation was studied by Bloembergen [5] and a comprehensive theory of surface nonlinear optics was established in Ref. [6].…”