Abstract:To achieve unidirectional transmission at 1.5μm wavelength for full optical logical element based on silicon substrate, a compound metal grating based on silicon was designed. Different incident directions of the photons onto the surface of the metal grating will cause different conditions for coupling surface plasmons. FDTD numerical simulation and optimization were utilized to adjust the optimum compound grating structure and the corresponding parameters. Experimental results show that the unidirectional transmission at the wavelength of 1.5μm is achieved with a maximum transmission 39% at the selected forward direction and the corresponding transmission contrast rate is up to 9.4.