Holography has become a vital platform for three-dimensional displays, optical encryption, and information processing, traditionally relying on the multiplexing of light's intrinsic properties such as wavelength, polarization, and orbital angular momentum (OAM). However, the exhaustive use of these physical degrees of freedom has saturated the parameter space, leaving little room for further scaling the capacity and security of holographic systems.
Now, researchers have broken this bottleneck by introducing a completely new, synthetic dimension to holography: the optical operator. In a new paper published in Light: Science & Applications , a team led by Professor Xianfeng Chen, and Professor Yuping Chen from Shanghai Jiao Tong University, China, in collaboration with Professor Yong Zhang from Nanjing University, China demonstrated this paradigm by realizing an OAM multiplication operator. This operator transforms a fractional OAM beam into an integer one through a customized pathway. The core innovation is an "operator-specific hologram," which remains locked unless illuminated with the exact, pre-defined operator pathway. Each pathway is defined by a unique combination of parameters—the incident topological charge, a scaling factor, and a propagation distance—which can be characterized by an unique helical trajectory in a 3D parameter space.
This approach unlocks unprecedented capabilities. For capacity, a single traditional OAM channel can be subdivided into multiple, independently addressable operator sub-channels. The team experimentally demonstrated a 9-fold increase in the capacity of a single OAM channel. For security, the team realized a 2-bit operator-multiplexed hologram, binarized and directly written into glass by femtosecond laser. The sender maps the plaintext to an ordered sequence of operator pathways, derives three synchronized parameter keychains with added noise obfuscation, and delivers them to the receiver. Only the correct assembly and sequential application of these keys reveals the correct hidden information and any parameter or ordering error collapses the output into speckle.
"This work moves beyond simply using what light naturally offers," said the team. "We engineer a new dimension—the operator—to gain ultimate control over holographic information. This creates a scalable and ultra-secure pathway for next-generation optical data storage, encryption, and displays."
Light Science & Applications
Optical operator-enabled holographic multiplexing