A Programmable High-Precision Real-Time Optical Beamforming Network Based on Galois Field

We propose a high-precision beam steering real-time control system that leverages optical true time delay (OTTD) based on serial <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> optical switch differential delay pairs. The pre-designed OTTD system utilizes a three-layer structure including a host computer, main control module, and delay module, containing a set of coding rules for mapping delay to switch as well as reducing programming redundancy and a set of communication modules for on-chip communication and real-time control. To address the challenge of ultra-short fiber lengths, we introduce a method based on Galois field principles, exploiting phase periodicity. This approach allows us to determine fiber lengths without fabricating excessively short fibers, ensuring effective phase traversal and thus improving the system’s flexibility. The experimental results show that the system can switch states in real-time within 0.24 ms, with an angular deflection range of 1° between −60° and 60° in simulations, showing the potential of our method for flexible beamforming design.