Figure 7
Four-port optical device as a summator. (a) The hatched area in the complex s(λ) plane, inside contours P, SUM2 and SUM3 and outside SUM1 (presented here for θ=π/2 and μ=0.5), represent the parameter space within which the four-port optical device can function as a summator. Under these conditions, the metamaterial described by line M can access this domain between λ1=844 and λ2=872 nm. (b) Spectral dispersion of the SUM1, 2 and 3 conditions on Iout (again for θ=π/2). The solid lines are derived from the sM(λ) approximation; the dashed lines are derived from the Sij coefficients of the metamaterial. In this representation, the device can function when the logic discrimination level μ lies below SUM1 and above SUM2 and SUM3.
