Design and analysis of all-optical AND, XOR and OR gates based on SOA–MZI configuration

The novel designs of all-optical logic gates using cross-gain modulation and cross phase modulation in semiconductor optical amplifiers, have been suggested and demonstrated successfully at 10 Gb/s. Mach–Zehnder configuration with two 3 dB couplers is used to introduce phase modulation on the saturated inverted output of SOA. No additional input beam such as clock signal or continuous light wave is used as in several other designs. In the designs, one data act as a pump and another act as a probe signal. Therefore, while passing through SOA, one data acting as a pump, saturates another data which is a probe signal. Different arrangements of input part of SOA–MZI, create three gates such as AND, XOR and OR. Gates are analyzed according to the extinction ratio, wavelength spectrum, frequency chirping and bit error rate. Very high extinction ratio is found i.e. 54.5, 36.32 and 37.5 at 1550.5 nm for AND, XOR and OR gates respectively. The wavelength spectrum, of all the three gates, lies within 1554.8 nm to 1555.2 nm which is near the central wavelength of probe pulse at 1550 nm. Negative frequency chirp are found for all the three gates with bit error rate 7.1×10 −30 , 1×10 −31 and 2.1×10 −12 for AND, XOR and OR respectively.