Optical amplifier systems utilizing both Raman fiber amplifiers and semiconductor optical amplifiers

摘要

PURPOSE: An optical amplifying system for combining a Raman fiber amplifier with a semiconductor optical amplifier is provided to improve performance by increasing output and reducing a noise index by using a Raman gain. CONSTITUTION: An optical signal entering an optical fiber for transmission(410) enters an isolator(430) through a wavelength division multiplexor(422a). A laser beam generated from a laser diode for Raman light amplification(421a) enters to the wavelength division multiplexor to be applied in an inverse direction of an incident signal light. The optical signal entering the isolator enters a gain fixed semiconductor optical amplifier(440). The isolator prevents back light from the gain fixed semiconductor optical amplifier for separating a Raman optical amplifier(420A) from the gain fixed semiconductor optical amplifier. The amplified optical signal is output through a second isolator(450).