DEVICE AND METHOD TO CHANGE SPECTRAL CHARACTERISTICS OF OPTICAL SIGNAL

摘要

PROBLEM TO BE SOLVED: To improve spectrum conversion efficiency. SOLUTION: On the basis of a solving method known as spectrum inversion (or light phase conjugation), a spectrum is changed. This device 1 generally includes a medium like a dispersion shift optical fiber 4. A signal to be varied is sent in the optical fiber together with a pump signal of level which causes modulation unstableness in the fiber 4. A spectrum-inverted light signal is obtained as the output of the fiber 4 and varied in wavelength and its conversion efficiency is high. The spectrum of the pump signal is preferably expanded by, for example, a modulator 5 so as to evade induced Brillouin scatter.