摘要
提出一种以相变材料为基础的低损耗可重构无阻塞光交换网络架构.首先,设计基于低吸收损耗相变材料Sb2Se3与马赫-曾德尔干涉仪(MZI)的2×2全光开关单元,通过光控Sb2Se3相变状态实现开关状态的切换.该单元无需外界持续的偏置电压即可保持开关状态,具有非易失性的特点,此外还能够降低功耗,减少芯片面积.基于此,通过Benes拓扑将2×2光开关与交叉波导级联,构建8×8无阻塞光交换网络.通过调整不同开关单元中Sb2Se3 的相变状态,实现8×8光交换网络中任意输入端口至输出端口的可重构光路交换.运用Ansys Lumerical仿真平台对所设计的2×2光开关及交叉波导结构进行仿真与优化,验证所提光交换网络的全连接无阻塞数据交换功能.仿真结果显示,所提2×2光开关的插入损耗和串扰噪声分别低于 0.072 dB和-55.66 dB,8×8 光交换网络的插入损耗和串扰噪声分别低于 0.500 dB和-45.00 dB.因此,所设计的低损耗性能优势的开关结构有助于实现大规模光子集成交换网络.
Abstract
Objective Mach‒Zehnder interferometer(MZI)-based optical switches are widely integrated into data-center optical switching networks owing to their exceptional performance in terms of bandwidth and temperature sensitivity.However,conventional electronically or thermally controlled MZI optical switches exhibit disadvantages of volatility,high insertion loss,and substantial footprint,thus complicating the scaling of the switching network.Hence,this study introduces a novel low-loss all-optical switch and an optical switching network structure based on nonvolatile phase-change materials to facilitate the implementation of large-scale data-center optical switching networks.Methods We propose a 2×2 all-optical switch structure based on nonvolatile phase-change material Sb2Se3 and an MZI[Fig.1(a)].By optically reconfiguring the state of Sb2Se3 within this structure,one can realize switching between the cross and bar states of this optical switch[Figs.1(b)and 1(c)].The 2×2 optical switches were interconnected by optimized low-insertion loss-crossing waveguides[Fig.4(a)]to form an 8×8 reconfigurable nonblocking optical switching network based on the Benes topology(Fig.3).To minimize loss in the optical switching network,the 2×2 optical switch and cross-waveguide structures were optimized using the Lumericalsimulation platform.Results and Discussions We constructed an 8×8 low-loss reconfigurable nonblocking optical switching network to simulate and verify the functionality of reconfigurable optical switching using the Lumerical INTERCONNECT simulation platform.Initially,we analyzed the state of each 2×2 optical switching unit of single-input light from ports I1 and I2 into the switching network from ports O1,O2,…,O8(Table 1).Subsequently,we obtained the simulation results for the insertion loss and crosstalk noise in the 8×8 optical switching network under different input and output ports.The simulation results indicate that the overall insertion loss of the optical switching network ranges from 0.296 dB to 0.463 dB,whereas the crosstalk is between-64.33 dB and-49.6 dB(Fig.5).We further analyzed the state of each 2×2 optical switching unit within the network by inputting light into all eight ports under various multi-input states(Table 2).Subsequently,we simulated the insertion loss of each output port under multiple multi-output states at an operating wavelength of 1550 nm(Fig.6).Additionally,we simulated a single-channel eye diagram with a data rate of 25 Gbit/s and obtained the extinction ratio,rise time,and fall time(Fig.7),which show relatively clear eye-diagram results under all states.Finally,we compared the proposed architecture with those of conventional 8×8 optical switching networks.The results show that the optical switching network based on Sb2Se3-MZI features a low insertion loss,low crosstalk,a compact footprint,and nonvolatile static zero power consumption(Table 3).Conclusions We present a reconfigurable 8×8 low-loss nonblocking optical switching network based on nonvolatile phase-change material Sb2Se3 and an MZI.This network comprises 20 Sb2Se3-MZI-based 2×2 optical switches and 16 optimized crossing waveguides interconnected via the Benes topology.Notably,a 2×2 optical switch unit is achieved through optically controlled Sb2Se3 phase states,thus obviating the conventional method of using an external voltage to control the phase state of the upper and lower arms in the MZI via electrode patches.This design offers low loss,minimal power consumption,and a compact chip area.Simulation results indicate that the proposed optical switching network enables parallel data exchange among all nodes while maintaining low insertion loss and crosstalk noise.This advancement contributes significantly to the development of large-scale data-center optical switching networks.
基金项目
国家自然科学基金(62205043)
国家自然科学基金(62222103)
国家自然科学基金(62221005)
国家自然科学基金(62071076)
国家自然科学基金(62075024)
国家自然科学基金(62001072)
重庆市自然科学基金(CSTB2022NSCQMSX1334)
NETL
NSTL
万方数据