On-chip differential mode group delay manipulation based on 3D waveguides

作者：Xiaofeng Liu, Quandong Huang, Jiaqi Ran, Jiali Zhang, Ou Xu, Di Peng, Yuwen Qin · 发表于：Chip · 年份：2025 · DOI：10.1016/j.chip.2025.100137 · 被引用次数：8 · 研究领域：Photonic and Optical Devices、Optical Network Technologies、Advanced Fiber Laser Technologies

Mode-division multiplexing based on few-mode optical fiber is a promising technology to increase the transmission capacity of optical communication systems, where multi-input multi-output (MIMO) digital signal processing (DSP) is employed to (de)multiplex the signals from different mode channels. Since the group velocity of each mode is different, the signals are separated in the time domain when they reach the receivers. Therefore, it is necessary to compensate for the mode-group-velocity delay of the interval modes to reduce the complexity of the MIMO-DSP algorithm. In this work, we demonstrate an on-chip differential-mode group delay (DMGD) manipulating device based on 3D multilayer cladding waveguides. The proposed device supports to compensate the DMGD of about 10.0 ps/m with device formed with low refractive index difference. In the meanwhile, the value of DMGD can be greatly improved to be 1878.6 ps/m by forming the device with high refractive index difference material such as thin-film lithium niobate with silicon dioxide cladding. The proposed device provides a feasible design for on-chip DMGD manipulating, which can find various applications in the mode division multiplexing system.