Patent ID: 7272325
Filing Date: 2007-09-18
Classification: H04B,H04J

Abstract:
1. An optical transmission device for transmitting a wave division multiplexed optical signal from a first optical transmission path to a second optical transmission path after amplification, comprising: an optical amplifier for amplifying the wave division multiplexed optical signal to generate an amplified wave division multiplexed optical signal; a first monitor connected to said optical amplifier for monitoring an amplitude of the wave division multiplexed optical signal to generate a first monitor signal; a first controller connected to said optical amplifier and said first monitor for controlling said optical amplifier so that an amplitude of the amplified wave division multiplexed optical signal reaches a predetermined value; a second monitor connected to said optical amplifier for monitoring an amplitude of the wave division multiplexed optical signal at a predetermined wavelength to generate a second monitor signal; a gain tilt setting unit connected to said first monitor for storing a gain tilt value which is obtained by dividing the first monitor signal by a number of wavelengths in the wave division multiplexed optical signal; a second controller connected to said optical amplifier and said second monitor for controlling the stored gain tilt value based upon the second monitor signal and the stored gain tilt value; a third monitor connected to said optical amplifier for monitoring an amplitude of the wave division multiplexed optical signal from the first optical transmission path before inputting into said optical amplifier; a fourth monitor connected to said optical amplifier for monitoring an amplitude of the wave division multiplexed optical signal at the predetermined wavelength from the first optical transmission path before inputting into said optical amplifier; and a calculation unit for controlling the gain tilt of said optical amplifier by approaching a first value to a second valve, the first value being obtained by dividing a total of an amplitude of the wave division multiplexed optical signal received from said third monitor in a second optical transmission device connected via the second optical transmission path and an amplitude of the wave division multiplexed optical signal received from said first monitor by a number of wavelengths in the wave division multiplexed optical signal, the second value being a total of an amplitude of the wave division multiplexed optical signal at the predetermined wavelength that is received from said fourth monitor in the second optical transmission device and an amplitude of the wave division multiplexed optical signal at the predetermined wavelength that is received from said second monitor.