Bridging Single‐Mode and Few‐Mode Fiber Systems via Multidimensional On‐Chip Optical Processing and Switching

Multidimensional optical communications based on few‐mode fibers (FMFs) have garnered considerable interest as a viable solution to the limitations of fiber transmission capacity. However, integrating FMFs with widely deployed single‐mode fiber (SMF) systems presents challenges. This incompatibility arises from differences in waveguide cross‐sections and the associated fiber‐mode solutions, compounded by an uncontrolled and unpredictable optical fiber transmission matrix. As a result, the implementation of optical switching is impeded by substantial channel cross‐talk. In this paper, a reconfigurable silicon photonic chip is presented that enables adaptive multidimensional channel switching between SMF and FMF links. The proposed silicon photonic chip eliminates the need for bulky benchtop equipment and power‐intensive, high‐latency digital signal processors. Instead, it facilitates efficient optical signal processing and enables arbitrary channel switching and add‐drop functionality among various optical fiber mode sets. An experimental channel cross‐talk of less than –17 dB is achieved. High‐speed signals at a data rate of 56 Gbps is used to validate the proposed method. Compared with prior methodologies, this approach is distinguished by its efficiency and compactness, thereby advancing the development of multidimensional optical fiber networks.