Optical rectification Hall effect in a one-dimensional grating.

We observe a transverse optical rectification current enhanced by surface plasmon polaritons in a one-dimensional gold thin film with a grating whose unit cell is asymmetric. In the linear regime, momentum transfer from incident laser light in one plane of incidence cannot yield an electrical current in the transverse direction. We show that a nonlinear system can cross-couple coordinates and lead to a transverse photocurrent despite no linear momentum transfer in the transverse direction. Nonlinear effects can be described by higher order terms in the polarization density expansion, which relates the polarization to the electric fields in the system, via linear and higher-order susceptibility tensor coefficients. We modify this expression with a phenomenological term to explain the counterintuitive observations. [ABSTRACT FROM AUTHOR]