A new modulation method to generate all-optical logic gates in an AOTF

Abstract

We propose a new method of optical modulation using a conventional acousto-optic tunable filter. In this device the all-optical logic gates, namely AND and OR, are obtained by simultaneously operation of optical double sideband (ODSB) modulation and a pulse position frequency domain modulation (PPFDM). This device shall operate with ultrashort soliton light pulses 100 ps. In this way, a pulse will carry two bits of information after been encoded by the modulation proposed here. We then analyze the modulation ODSB—PPFDM for input pulses, polarized in the two input modes, allowing a variation in the modulation parameter for each input pulse. A phase difference Δϕ = π rad was considered between both input pulses, it was obtained the occurrence of an AND (OR) logical gate at lower (upper) sideband of the TE output pulse as well as at upper (lower) sideband of the TM output pulse.