Spectral Properties of Approximations of Optical Signals by Gaussian Pulses

Increasing the capacity of data transmission systems reduces, among other things, to the task of improving spectral efficiency. One possible approach to solving this problem is to use the alphabet of optical signals having approximately the same dispersion expansion at the receiving side. A problematic, both technically and theoretically, is the possibility of forming a low-frequency envelope of an optical signal of a given shape. The work is devoted to the development of the theory of approximation of signals of a given shape by pulses (counting functions) of a Gaussian form. The boundary estimates of the effective width of the spectra of signal sequences generated by weighted sums of Gaussian pulses are obtained.