Stabilization of Multimode Fiber Link by Simple Insertion of Low-Noise Plastic Optical Fiber

Data transmission in a multimode fiber (MMF) link is significantly improved by simply inserting a low-noise graded-index (GI) plastic optical fiber (POF) between a vertical-cavity surface-emitting laser and standard silica GI MMF, compared with using only the silica GI MMF as a transmission medium. The developed low-noise GI POF exhibits strong mode coupling closely related to the microscopic heterogeneous structures in the fiber core material; this effectively reduces interferometric noise in the MMF link. Experimental results demonstrate that the insertion of the low-noise GI POF reduces the bit error rate by several orders of magnitude in 53.125 Gb/s data transmission using four-level pulse amplitude modulation, owing to significant noise suppression despite the presence of insertion loss. This simple configuration reduces the need for additional noise mitigation in transceiver modules and precise connector designs, enabling cost-effective implementation of MMF links while ensuring robust and reliable operation.