Raman amplifier having large bandwidth

摘要

A plurality of pump light sources (11-1 through 11-8) generate plural variations of pump light having different frequencies. A modulation circuit (12) intensity-modulates the plural variations of pump light in the predetermined periods, respectively. A pump light pair whose frequency difference equals a Raman shift frequency are modulated such that they cannot simultaneously enters an emission state. A wavelength-multiplexer (13) wavelength-multiplexes the plural variations of pump light modulated by the modulation circuit (12). A optical guide device (14) guides the plural variations of pump light wavelength-multiplexed by the wavelength-multiplexer (13) to an optical fiber.