Patent ID: 9007680
Filing Date: 2015-04-14
Classification: H01S,H04B,H04J

Abstract:
1. An apparatus comprising: an optical amplifier which amplifies a wavelength division multiplexed optical signal having a variable number of channels associated with different wavelengths and outputs the amplified WDM optical signal, the optical amplifier including: a first optical amplifier which amplifies the wavelength division multiplexed optical signal and outputs the first optical amplifier amplified wavelength division multiplexed optical signal, a variable optical attenuator which controls a level of the first optical amplifier amplified wavelength division multiplexed optical signal and outputs the controlled wavelength division multiplexed optical signal, a second optical amplifier which amplifies the controlled wavelength division multiplexed optical signal and outputs the amplified, controlled wavelength division multiplexed optical signal, and a controller which controls the wavelength division multiplexed optical signal to be amplified with a constant gain.