Dynamic coded encryption using tunable spatial coherence of random lasers

Random lasers hold significant promise in the field of information encryption due to their advantages of low spatial coherence and multi-degree-of-freedom control. We propose a dynamic coded encryption approach based on the tunable spatial coherence of random lasers. By varying the magnitude of the external voltage applied to the sample, the spatial coherence of the random laser can be reversibly changed. This phenomenon derives from the electric dipole moment effect in liquid crystals, where the application of voltage causes deflection of the liquid crystal molecules, leading to a change in the refractive index, and consequently affecting the spatial coherence of the random laser. Therefore, multiple visibility outputs, which are utilized for dynamic coded encryption, can be achieved through the double-slit interference method by applying different voltages to the sample array. Information encryption transmission is accomplished by interconverting the data into ASCII code according to different systems based on binary or quaternary digits. Moreover, pulse time series of random laser visibility can be realized by modulating the voltage in real time for individual samples, facilitating a compact encryption system. This work is expected to inspire the application of random lasers in secure data storage and information encryption.