AI 中文总结
该研究针对基于相移键控的相干光纤系统，以高斯-厄米函数为正交基表征噪声场，推导相位方差与最优发射功率的解析表达式，明确了高阶噪声模对线性及非线性相位噪声的影响机制。
AI 中文摘要
本文推导了基于相移键控的非线性光纤系统中相位方差的解析表达式。研究采用Gauss-Hermite（高斯-厄米）函数作为正交基来表征噪声场，并估算了精确建模相位方差所需的自由度（DOF）数量。放大器噪声会激发高阶高斯-厄米噪声模，信号脉冲与高阶高斯-厄米噪声模的非线性混合会产生新的噪声场，进而加剧非线性相位噪声。若接收端未使用匹配滤波器，高阶噪声模会线性传输并增大线性相位噪声。本文还综合考虑线性与非线性相位噪声，推导出了最优发射功率的解析表达式。
英文摘要
Analytical expressions for the phase variance in a nonlinear fiber optic system based on phase-shift keying are developed. The Gauss-Hermite functions are used as the orthogonal basis to represent the noise field. Number of degrees of freedom (DOF) to accurately model the phase variance is estimated. The amplifier noise excites higher order Gauss-Hermite noise modes and the nonlinear mixing of a signal pulse and higher order Gauss-Hermite noise mode leads to new noise fields which enhance the nonlinear phase noise. The higher order noise modes propagate linearly and enhance the linear phase noise if the matched filter is not used at the receiver. Analytical expression for the optimum launch power is developed taking into account the linear and nonlinear phase noise.
Journal refS. Kumar, Journal of Lightwave Technology, Vol. 27, No. 21, p. 4722, 2009
