Bistable diode action in left-handed periodic structures
  We study nonlinear transmission of an asymmetric multilayer structure created by alternating slabs of two materials with positive and negative refractive index. We demonstrate that such a structure exhibits passive spatially nonreciprocal transmission of electromagnetic waves, the analogue of the electronic diode. We study the properties of this left-handed diode and confirm its highly nonreciprocal and bistable transmittance by employing direct simulations. 
Michael W. Feise, Ilya V. Shadrivov, and Yuri S. Kivshar