光交换芯片中串扰的相干特性研究  

Crosstalk Coherence in Optical Switching Chips

作　　者：汤宇 武保剑[1] 严伟 文峰[1] 邱昆[1] TANG Yu;WU Baojian;YAN Wei;WEN Feng;QIU Kun(Key Laboratory of Optical Fiber Sensing and Communications,Ministry of Education,University of Electronic Science and Technology of China,Chengdu 611731,China)

机构地区：[1]电子科技大学光纤传感与通信教育部重点实验室,成都611731

出　　处：《光子学报》2023年第10期199-208,共10页Acta Photonica Sinica

基　　金：国家自然科学基金(No.62171078)。

摘　　要：以马赫-曾德尔干涉仪光开关单元组成的4×4 Benes光交换芯片为例,研究了光交换芯片中的相干问题。理论推导了光交换芯片输出端口与输入端口之间光场的变换关系,揭示了信号和串扰的产生规律,分析了光开关状态对串扰相干强度的影响。仿真研究表明:相干串扰对信号插损的影响可以忽略;在不同光开关组合状态下,光交换芯片的串扰波动可达7 dB。根据相干光束之间的相位关系,提出一种等效去除光交换芯片中串扰相干性的方法。另外,对串扰大小对通信误码率的影响进行了实验评估。With the rapid development of information and communication technology,optical switching is more desirable for communication networks with low latency and high data rates than traditional Opto-Electro-Opto(O-E-O)operating.The latter easily suffers from the so-called“electronic bottleneck”,and then high latency and power consumption.All-optical switching can steer data signals to the destination ports in the optical domain,and possesses the transparency of signal format,bit rate,and protocol.Siliconbased optical switching chips have been employed to realize Wavelength-Division Multiplexing(WDM)network nodes,with small size,low power consumption,and fast switching speed,which are also expected to be suitable for future Space-Division Multiplexing(SDM)all-optical switching nodes.In these chips,the connection paths are usually shorter than the coherent length of light,and the coherent effect between two beams from the same light source will take place,resulting in the power fluctuation of optical signals or crosstalk increase.In the paper,we focus on the 4×4 Benes optical switching chip,composed of 2×2 Mach-Zehnder Interferometer(MZI)optical switches,in which the optical couplers are realized by Multimode Interference(MMI)devices.The transmission matrix method is used to deduce the transfer function of input to output optical fields for the optical switches and the whole chip.Here,we take into account the crosstalk coherence caused by the imperfect 3 dB MMIs in the MZI optical switches.Based on coherence theory,the assumption is made that the optical fields of only coherent light beams can be added.In other words,the transmission matrix model is suitable for single-port input cases in calculations.For multi-port inputs,optical intensities are calculated separately for each input port to avoid superimposing the optical fields of different sources during calculations.By analyzing the expression of the transmission matrix,it can be observed that if the states of middle switches are the same,the coherence effects h

关 键 词：光交换芯片 相干效应 Benes结构 马赫-曾德尔干涉仪 串扰 

分 类 号：TN913.7[电子电信—通信与信息系统]