MULTI-LAYER SUBWAVELENGTH STRUCTURES FOR IMPARTING CONTROLLABLE PHASE DELAY

摘要

An integrated optical device 200 includes a semiconducting or electrically insulating substrate 205, a first metal layer 210 disposed on the substrate having a plurality of spaced apart subwavelength features, and at least a second metal layer 215 disposed on the substrate having a plurality of spaced apart subwavelength features. The second layer is spaced apart from the first layer by dielectric layer 212, but dielectric layer 212 is sufficiently thin to produce evanescent field coupling between layers 210 and 215. The features of the first and second metal layer are laterally shifted with respect to one another along at least a portion of a length of the device.