The positive and negative frequency expressions of quasi-monochromatic optical fields of a pulse in fiber-optic communication and the positive and negative frequency forms of Fourier transformations and nonlinear Schr?dinger (NLS) equations are discussed.

• 摘要讨论光通信中脉冲的准单色光光场的正负频表示，正负频形式的傅里叶变换，正负频形式的非线性薛定谔方程及它们之间的关系。