Laser-induced diffraction grating in asymmetric double quantum well nanostructure

摘要

We analyze the electromagnetically induced grating in a four-level inverted-Y double quantum well system. Based on the electromagnetically induced transparency, the Fraunhofer diffraction of a weak probe laser field is theoretically investigated. It is shown that the diffraction patterns are sensitive to both the absorptive and dispersive properties of the system. The effect of coupling and pumping fields intensity, frequency detuning, the relative phase of fields and the sample interaction length on diffraction pattern is then discussed. Our scheme may find potential applications in designing the semiconductor quantum well-based photonic devices, such as all-optical switches at low light levels.