Patent ID: 7570888
Filing Date: 2009-08-04
Classification: H04B

Abstract:
1. A fiber optic transmission system, comprising: a signal coupler receiving an input modulating signal to generate a first electrical output representative of said input modulating signal and a second complementary electrical output which has a phase shift of 180 degrees with respect to said first electrical output; two optical transmitters connected to receive said first and said second electrical outputs, respectively, to produce two optical signals which are modulated by said first and said second electrical outputs, respectively; two optical linearizers respectively located in optical paths of said two optical signals to optically modify said two optical signals, respectively, to reduce signal distortions thereof; and a feedback loop comprising an optical coupler connected to an output of at least one of the two optical linearizers configured to provide an optical monitor signal, an optical detector configured to receive said optical monitor signal to produce a detector output, a distortion control module configured to receive the detector output and to produce a distortion control signal to control at least one of said optical transmitters or one of said optical linearizers to further reduce signal distortions; and a wavelength control unit configured to receive said distortion control signal and control a wavelength of at least one of said optical signals.