NONLINEAR FIBER AMPLIFIERS USED FOR A 1430-1530nm LOW-LOSS WINDOW IN OPTICAL FIBERS

(57) -- it can use using the parallel combination of a summary light amplifier by the low loss window in an optical fiber (from 1430 nm to 1620 nm) -- abbreviated -- the equipment and the method for enabling use of a perfect 25-THz belt are described. The low loss window at about 1530 nm * 1620 nm can be amplified using an erbium dope fiber amplifier (EDFA). However, EDFA cannot be used at about 1520 nm or less without considerable degradation of performance because of the intrinsic absorption of erbium in a shorter wavelength. The amplifier based on nonlinear polarization of an optical fiber day can be effectively used to the low loss window in about 1430 nm * 1530 nm. The broadband nonlinear polarization amplifier (NLPA) which combines cascade ラマン amplification with parametric amplification or 4 wave mixture is indicated. In particular, it is the middle cascade ラマン degree wavelength lambda. One is the zero distribution wavelength lambda of an amplification fiber. It should be approached and located. Spectrum broadband-ization carries out phase matching to 4 wave mixture (when it is lambda <lambda) or phase matching parametric amplifier to this middle Raman degree (when it is lambda >lambda). In a higher cascade ラマン degree, a gain spectrum continues being broadband-ized for the convolution of gain スプクトル and the spectrum from the front Raman degree.