This cluster of papers focuses on the research and development of Optical Code Division Multiple Access (CDMA) systems, particularly emphasizing topics such as Fiber Bragg Grating, Spectral Amplitude Coding, Security Performance against eavesdropping, Coherent and Incoherent Systems, Rank Modulation for Flash Memories, Latin Squares, Photonic Routers, Error Correction techniques, Orthogonal Codes, and Wavelength-Time Codes.