Defective states of Hermite-Gaussian modes for long-distance image transmission and high-capacity encoding

Structured light brings a breakthrough in information capacity carried by the laser field, finding an ideal utility in optical information transmission. Advancements in optical intensity-based imaging have facilitated the use of structured light for simple information enconding and decoding. Here, we propose a method for extremely high-capacity information encoding, as well as image direct transmission, by modulating the structured light to defective states. Using well-designed two-dimensional binary hologram gratings to generate distinct defects within a single Hermite-Gaussian mode, we achieve over 10ⁿ (n > 10) of laser states for encoding, corresponding to information capacity being tens of bits. These defective states are recognized by image processing method for quick decoding. In addition, various image patterns can also be generated and are possible to achieve long-distance transmission with high fidelity. It means that images can be directly transmitted for long distance without digital encoding process, which paves a simple way for information transmission.