Green A G, Mitra P P, Wegener L G L
Theoretical Physics, Oxford University, Oxford, OX4 4BB, UK.
Opt Lett. 2003 Dec 15;28(24):2455-7. doi: 10.1364/ol.28.002455.
We consider the combined effects of amplified spontaneous emission noise, optical Kerr nonlinearity, and chromatic dispersion on phase noise in an optical communication system. The effect of amplified spontaneous emission noise and Kerr nonlinearity were considered previously by Gordon and Mollenauer [Opt. Lett. 15, 1351 (1990)], and the effect of nonlinearity was found to be severe. We investigate the effect of chromatic dispersion on phase noise and show that it can either enhance or suppress the nonlinear noise amplification. For large absolute values of dispersion the nonlinear effect is suppressed, and the phase noise is reduced to its linear value. For a range of negative values of dispersion, however, nonlinear phase noise is enhanced and exhibits a maximum related to the modulation instability found in amplitude fluctuations. Nonlinear phase noise is quenched by these effects even in dispersion-compensated systems; the degree of suppression is sensitively dependent on the dispersion map. We demonstrate these results analytically with a simple linearized model.
我们考虑了放大自发辐射噪声、光学克尔非线性以及色散对光通信系统中相位噪声的综合影响。戈登和莫伦瑙尔[《光学快报》15, 1351 (1990)]之前曾考虑过放大自发辐射噪声和克尔非线性的影响，发现非线性效应很严重。我们研究了色散对相位噪声的影响，并表明它既可以增强也可以抑制非线性噪声放大。对于绝对值较大的色散，非线性效应受到抑制，相位噪声降低到其线性值。然而，对于一定范围的负色散值，非线性相位噪声会增强，并表现出与幅度波动中发现的调制不稳定性相关的最大值。即使在色散补偿系统中，这些效应也会抑制非线性相位噪声；抑制程度敏感地取决于色散分布图。我们用一个简单的线性化模型对这些结果进行了分析论证。
