Design of a Two-Dimensional Photonic Crystal-Based Optical Encoder for Marine Communication Systems

Marine communication systems have always faced challenges such as signal attenuation, wave interference, and bandwidth limitations. The use of photonic crystals as a platform for implementing optical encoders in communication systems has attracted the attention of researchers due to the unique features of these structures, such as precise light guiding and dispersion control. Optical encoders are circuits used in the design of optical processors. To reduce the size of optical devices, it is essential to design small-scale logic circuits. In this study, a 2×4 all-optical encoder based on two-dimensional photonic crystals is designed and simulated. The simple structure of this optical encoder enables its use in integrated optical circuits. Due to its small-scale structure and the use of defect pathways, the encoder’s transmission delay is reduced, resulting in an increased data bit rate. The transmission delay obtained for this proposed encoder is less than 90 femtoseconds. Another feature of this proposed optical encoder is that the optical output power in the logic "0" state is very low, which increases the contrast ratio.