Recent advances in photonic crystal-based encoder and decoder designs: a comprehensive review Ayesha Sultana, Haraprasad Mondal, Himanshu Das, Mohammad Soroosh and Sagar Bhattarai Eur. Phys. J. Plus, 140 6 (2025) 536 Published online: 16 June 2025 DOI: 10.1140/epjp/s13360-025-06495-7