A compact and low-loss multimode waveguide bend plays a significant role in multimode channels and highdensity on-chip optical interconnection architectures,and it has become a key component of photonic integrated chi...A compact and low-loss multimode waveguide bend plays a significant role in multimode channels and highdensity on-chip optical interconnection architectures,and it has become a key component of photonic integrated chips.Here,we propose an inverse design method based on staged optimization of high-order Bezier curves with high degrees of freedom,which effectively overcomes the optimization limitations of traditional geometric curve design.Using this approach,we demonstrate an ultra-compact 90°multimode waveguide bend on a 220 nm silicon-on-insulator(SOl)platform,featuring an effective bending radius as small as 9μm and supporting four TE modes.Furthermore,the bend is extended to arbitrary angle interconnects,with 60°,120°,and 180°configurations as examples,significantly enhancing the flexibility and adaptability of on-chip compact multimode interconnections.Simulation results show that 90°bend exhibits excellent performance at 1550 nm with excess losses below 0.038 dB and crosstalk below-30 dB.The proposed design was further fabricated and experimentally characterized.The maximum measured excess loss is 0.13 dB,and the inter-mode crosstalk is all below-25 dB at 1550 nm.This device combines ultra-compact footprint,low loss,and excellent scalability,suitable for high-density on-chip interconnects.展开更多
基金National Natural Science Foundation of China(62305381,62105152,62525509)Fundamental Research Funds for the Central Universities(30919011401,30922010204,30922010718,JSGP202202)+4 种基金Funds of the Key Laboratory of National Defense Science and Technology(6142113210205)Leading Technology of Jiangsu Basic Research Plan(BK20192003)National Defense Pre-Research Foundation of China during the 14th Five-Year Plan Period(D040107)Jiangsu Funding Program for Excellent Postdoctoral TalentPostgraduate Research Practice Innovation Program of Jiangsu Province。
文摘A compact and low-loss multimode waveguide bend plays a significant role in multimode channels and highdensity on-chip optical interconnection architectures,and it has become a key component of photonic integrated chips.Here,we propose an inverse design method based on staged optimization of high-order Bezier curves with high degrees of freedom,which effectively overcomes the optimization limitations of traditional geometric curve design.Using this approach,we demonstrate an ultra-compact 90°multimode waveguide bend on a 220 nm silicon-on-insulator(SOl)platform,featuring an effective bending radius as small as 9μm and supporting four TE modes.Furthermore,the bend is extended to arbitrary angle interconnects,with 60°,120°,and 180°configurations as examples,significantly enhancing the flexibility and adaptability of on-chip compact multimode interconnections.Simulation results show that 90°bend exhibits excellent performance at 1550 nm with excess losses below 0.038 dB and crosstalk below-30 dB.The proposed design was further fabricated and experimentally characterized.The maximum measured excess loss is 0.13 dB,and the inter-mode crosstalk is all below-25 dB at 1550 nm.This device combines ultra-compact footprint,low loss,and excellent scalability,suitable for high-density on-chip interconnects.
