Fig. 4

Experimental multiplication results. a Experimental setup to multiply to input energies. A variable optical attenuator (VOA) and a beam splitter (BS) are used to monitor the input energies to the two photon absorption (TPA) units. A polarization beam combiner (PBC) was used to combine the input energies from two arms as well as preserving their polarization in order to avoid interference at saturable absorber (SA). b, c Experimental TPA data (square) and the nonlinear fit E_out = H.ln(Q.E_in) (solid lines) where H = 0.148 µJ and Q = 33.663 µJ⁻¹. The error bars denote the standard deviation of reading input and output energy per pulse for 200 shots for each data point. d Experimental SA data (triangle) and the nonlinear fit E_out = h.exp(q.E_in) (solid line), where h = 0.247 µJ and q = 0.401 µJ⁻. The error bars are the same as in b, c. e The measured final energy output vs. multiplication of the input values. The solid green line shows ideal multiplication. The error bars show the relative percent error between experimental readout and ideal multiplication of two energy inputs. f Modification of Fig. 2a schematic capable of performing an ideal multiplication. It requires two gain blocks, G₁ and G₂ in which the values of the gains depend on the material and the experimental setup