Simultaneous all optical half adder, half subtracter, comparator, and decoder based on nonlinear effects harnessing in highly nonlinear fibers
Abstract. A multifunctional combinational logic module capable of performing several signal manipulation tasks all optically, such as half addition/subtraction, single bit comparison, and 2 to 4 decoding simultaneously is proposed. Several logic functions (A+B A.B, A .B, A.B AB, and AB) between two input signals A and B are implemented by harnessing a number of nonlinear effects, such as cross phase modulation (XPM) cross gain modulation (XGM) and four wave mixing (FWM) inside only two highly nonlinear fibers (HNLF) arranged in a parallel structure. The NOR gate (A+B is realized by the means of XPM effect in the first HNLF, whereas, A .B, A.B and A.B logics have relied on utilization of XGM and FWM processes, respectively, in parametric medium made up of the second HNLF of parallel arrangement. The remaining AB and AB logics required for successful implementation of the proposed simultaneous scheme are attained by temporally combining previously achieved (A .B and A.B and (A.B and A+B logics. Quality factor =7.4 and extinction ratio =12.30 dB have been achieved at repetition rates of 100 Gbps for all logic functions (A+B A.B, A .B, A.B AB, and AB) suggesting successful simultaneous implementation.