为了满足光载太赫兹通信对低相噪高稳定性的多载波光源的需求,提出了一种基于电吸收调制器(electro-absorption modulator,EAM)、强度调制器(intensity modulator,IM)和EAM级联的高平坦可调谐光频梳(optical frequency comb,OFC)信号产生方案。在方案中,基于初级EAM产生OFC信号,利用IM进一步提升梳齿数目,最后通过调节第二级EAM的驱动电压优化平坦度。仿真结果显示,该方案可产生最高带宽为800 GHz的21线OFC信号,平坦度达到0.52 dB。随后分析了方案中关键器件的工作参数对其性能的影响。为进一步验证产生OFC信号的通信性能,通过仿真分析了单通道或多通道在背对背(back to back,BTB)、10 km光纤和15 m无线3种情况下传输256阶正交幅度调制(256-ary quadrature amplitude modulation,256QAM)信号的性能。结果表明,上述每种情况下的误码率(bit error rate,BER) 都低于前向纠错编码判决阈值3.8×10-3。

In order to meet the requirements of low phase noise and high stability multi-carrier light source for terahertz communication over fiber,a high flat tunable optical frequency comb (OFC) signal generation scheme based on an electro-absorption modulator (EAM),an intensity modulator (IM),and an EAM cascade is presented.In the scheme,based on the primary EAM,the optical frequency comb signal is generated,the number of combs is further increased by IM,and the flatness is optimized by adjusting the drive voltage of the second EAM.The simulation results show that this scheme can generate a 21 line optical frequency comb signal with a maximum bandwidth of 800 GHz,with a flatness of 0.52 dB.Subsequently,the impact of the operating parameters of key components in the scheme on their performance is analyzed.To further verify the communication performance of generating optical frequency comb signals,the performance of single or multi-channel transmission of 256-ary quadrature orthogonal amplitude modulation (256QAM) signals is analyzed through simulation under three conditions of back to back (BTB),10 km fiber,and 15 m wireless.The results indicate that the bit error rate (BER) in each of the above cases is lower than the forward error correction coding decision threshold of 3.8×10-3.

TN761

陕西省自然科学基金(2023-JC-JQ-58)和陕西省创新能力支撑计划(2021TD-09) 资助项目