Patent ID: 6587242
Filing Date: 2003-07-01
Classification: H04B,H04J

Abstract:
An optical transmission system that transmits to an optical receiver a signal light sent from an optical transmitter via a plurality of optical transmission fibers connected in serial and an optical linear repeater or an optical regenerator repeater, comprising:an optical transmitter including: an optical time division multiplexed signal generating means that outputs an optical time division multiplexed OTDM signal having a wavelength &lgr;0 that has a time division multiplexed signal light having N lines (N is an integer equal to or greater than 2) and having a bit rate mif0(i=1, 2, . . . , N, where m1 is an integer equal to or greater than 1) that is an integral multiple of a fundamental frequency f0; a control light generation means that generates control signal light wherein an optical pulse train, having a wavelength &lgr;1 equal or almost equal to the wavelength of the OTDM signal and having a bit rate kf0 that is an integral multiple of the fundamental frequency f0 that are synchronized with the OTDM signal, is modulated by control information of said OTDM signal; an optical pulse broadening means that broadens the optical pulse waveform of the control signal in a time range, and outputs a control light having an optical peak intensity set sufficiently low in comparison to the OTDM signal peak intensity; and an optical coupling means that multiplexes the OTDM signal and the control light and delivers them to the optical transmission fiber; and an optical receiver including: a light splitting means that splits into two parts the transmitted light; an optical pulse narrowing means that restores the control light that includes a part of the light split by the optical splitting means to the original optical pulse train; an optoelectric conversion means that converts the output light of the optical pulse narrowing means to an electric signal; a control signal processing means that extracts from the electrical signal information relating to the optical time division multiplexing of the OTDM signal and control information including a timing clock; and an optical time division demultiplexing means that, depending on the control information, carries out optical time division demultiplexing of the OTDM signal into an N line signal light included in the other portion of light split by the optical splitting means.