Plasmon-induced phase grating via nonlinear modulation

By studying the linear and nonlinear properties of four-level quantum system near plasmonic nanostructure (PS), it is realized that the diffraction efficiency of weak probe light can be controlled by plasmon induced linear and nonlinear modulation. We investigated that due to presence of plasmonic nanostructure, the giant Kerr nonlinearity with vanishing linear and nonlinear absorption can be obtained. In this case, a weak probe light can be diffracted to the higher-order direction due to modulation of nonlinear susceptibility.