SCHEME FOR MEASURING OF NONLINEAR TRANSMISSION COEFFICIENT OF OPTICAL FIBRE

摘要

The invention pertains to the field of telecommunications, more specifically to sector of optical wavelength division multiplexing transmission systems, where optical amplifiers are employed as a result input signal power in optical fibre increases, and nonlinear optical effects start to influence optical signal propagation in optical fibre. Optical fibre nonlinear characteristics describe nonlinear coefficient. The aim of invention is to achieve practically useable nonlinear coefficient value for 10 Gbit/s optical wavelength division multiplexing systems by using pulsed signal self-phase modulation optical fiber nonlinear coefficient measurement scheme, that employ laser with external amplitude modulation. Pulse following frequency in modulated signal is 10 Gbit/s, that corresponds to synchronous digital hierarchy data transmission speed hierarchy level STM-64 and is used in 10 Gbit/s wavelength division multiplexing systems as each seperate channel data transmission speed. The measured nonlinear coefficient value is directly useable for estimation of optical fiber nonlinear characteristics.