Fig. 3
From: Nonlinear optical components for all-optical probabilistic graphical model
Numerical simulation of multiplication. a Comparison of the saturable absorption (SA) solution with an exponential function Eout = h.exp(q.Ein). Fit coefficients are h = 2.906 and q = 0.041 and parameter values of the numerical simulation are α0 = 5(arb.u.),Esat = 70(arb.u.) and L = 0.3(arb.u.). b Comparison of two photon absorption (TPA) solution with a natural logarithm function Eout = H.ln(Q.Ein). Fit coefficients are H = 0.646 and Q = 0.723 and parameter values of the numerical simulation are α0 = 5(arb.u),L = 0.3(arb.u.) and β =0.5(arb.u.). c The blue squares show the composite mathematical operations of ln-sum-exp for 29 inputs and the solid red line represents ideal multiplication. The normalized-root-mean-square (NRMSE) of less than 1% (between simulated multiplication and the ideal multiplication) occurs between the bounded range, which is input energies between about 19 (arb.u.) to 32 (arb.u.)
