Selectively Visualizing the Hidden Modes in Random Lasers for Secure Communication

Abstract Toward a higher degree of secure communication, great efforts have been made to develop encryption and anticounterfeiting strategies. In particular, optical encryption with high complexity has become one of the most significant approaches. To strengthen optical information security, the concept of a spectral encryption approach is proposed based on selectively visualized spectral modes in random lasers. By coupling with external whispering gallery mode cavity, hidden localized lasing modes with special multiple‐peaks spectra are selected from phase‐correlated random lasers with smooth single‐peak spectra. The selectively visualized localized modes are utilized for spectral encryption of secure information. The encoded spectral modes that are hidden in phase‐correlated modes with identical spectra can only be selectively recognized by a special external coupler. This multiplex encryption strategy is super for the simple operation, low cost, and high security, supplying a new approach for further applications in secure communication and anticounterfeiting.