Cascadable all-optical XOR gates for optical ciphertext and all-optical parity calculations

Current research in optical computing and all-optical communications requires functionality that employs photons instead of electrons. Because of optical communications, there is a substantial research in developing elemental optical logic functions such as AND, OR, INVERT, and XOR. The latter logic function is one of the most important because of its versatility in encoding optical ciphertexts or decoding them, and also in designing optical macro-functions such as parity calculators. In this paper, we present an all-optical XOR gate that requires neither synchronization nor multi-wavelength control signals, and thus it is simpler to implement than other designs, it is cascadable and it is monolithically integrable. We simulate the all-optical XOR gate, we show its use in generating optical ciphertexts, and we demonstrate its cascadability towards an all-optical parallel parity generator.