2017/05/01 by Gerhard Kramer, Kramer, Gerhard
Engineering · #Advanced Photonic Communication Systems #FOS: Computer and information sciences #Information Theory (cs.IT) #Optical Network Technologies #Semiconductor Lasers and Optical Devices
paper · pdf · doi:10.48550/arxiv.1705.00454
openalex publication_date 2017/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Optical fiber signals with high power exhibit spectral broadening that seems\nto limit capacity. To study spectral broadening, the autocorrelation function\nof the output signal given the input signal is derived for a simplified fiber\nmodel that has zero dispersion, distributed optical amplification (OA), and\nidealized spatial noise processes. The autocorrelation function is used to\nupper bound the output power of bandlimited or time-resolution limited\nreceivers, and thereby to bound spectral broadening and the capacity of\nreceivers with thermal noise. The output power scales at most as the\nsquare-root of the launch power, and thus capacity scales at most as one-half\nthe logarithm of the launch power. The propagating signal bandwidth scales at\nleast as the square-root of the launch power. However, in practice the OA\nbandwidth should exceed the signal bandwidth to compensate attenuation. Hence,\nthere is a launch power threshold beyond which the fiber model loses practical\nrelevance. Nevertheless, for the mathematical model an upper bound on capacity\nis developed when the OA bandwidth scales as the square-root of the launch\npower, in which case capacity scales at most as the inverse fourth root of the\nlaunch power.\n