摘要
噪声系数与二阶谐波抑制比是衡量微波光子链路性能的关键指标。噪声系数表征信号信噪比的劣化程度,主要受激光器相对强度噪声、探测器散粒噪声以及电路热噪声影响;二阶谐波抑制比(2nd-HD Suppression Ratio,2HD)反映系统抑制非线性失真的能力。针对直调微波光链路性能优化问题,提出了基于偏置点调控的双目标优化方法。通过建立直调光链路传递模型,对器件参数与链路性能之间的映射关系进行理论分析。实测对比了不同直调激光器输出光功率条件下,链路噪声系数和二阶谐波抑制比。结果表明,在直调激光器线性工作区内,保持链路增益稳定,将1550 nm激光器输出光功率降低3 dBm可使噪声系数改善2.6 dB,而2HD恶化2.44 dB。研究表明,噪声系数与谐波抑制比存在制约关系,需根据实际应用需求合理选择最优偏置工作点,这为直调链路在通信、雷达及传感系统中的自适应优化提供了理论依据。
Noise figure(NF)and second harmonic distortion suppression ratio(2HD)are critical metrics for evaluating the performance of microwave photonic links.The NF characterizes the degradation of the signal-to-noise ratio and is primarily influenced by laser relative intensity noise,detector shot noise,and thermal noise.The 2HD reflects the limitation of nonlinear distortion on signal integrity.This paper proposes a dual-objective optimization method based on bias point adjustment to address the performance optimization of directly modulated microwave photonic links.The mapping relationships between the device parameters and link performance are theoretically analyzed based on establishment of a transfer model for the directly modulated optical link.Experimental measurements compare the NF and 2HD under different output power levels of the directly modulated laser.The results show that within the linear operation region of the laser,reducing the output power of a 1550 nm wavelength laser improves the NF by 2.6 dB and maintains consistent link gain but deteriorates the 2HD by 2.44 dB.The study demonstrates a significant trade-off between the NF and harmonic suppression ratio,which necessitates dynamic selection of the optimal bias point based on practical application requirements.This work provides a foundation for flexible optimization of directly modulated links in communication,radar,and sensing systems.
作者
彭若雪
陈诺
肖永川
瞿鹏飞
华勇
PENG Ruoxue;CHEN Nuo;XIAO Yongchuan;QU Pengfei;HUA Yong(Chongqing Optoelectronics Technology Institute,Chongqing 400060,CHN)
出处
《半导体光电》
北大核心
2025年第1期122-126,共5页
Semiconductor Optoelectronics
关键词
微波光子学
直调光传输链路
噪声系数
二阶谐波抑制比
偏置点优化
microwave photonics
direct-modulated optical transmission links
noise figure
second harmonic distortion suppression ratio
bias point optimization
