Patent ID: 7536108

Claim:
A method of measuring chromatic dispersion of an optical transmission line, comprising: transmitting on the optical transmission line a single digital optical signal generated by using a single light source on an optical transmission line, the digital optical signal being a carrier suppressed RZ encoded optical signal generated using a carrier suppressing device and binary NRZ code or partial response code, a carrier suppressed clock signal generated using a carrier suppressing device and a clock signal, an NRZ encoded optical signal, an RZ encoded optical signal, or an optical clock signal; receiving the same single digital optical signal transmitted on the optical transmission line; optically separating at least two band components of different frequencies from the received same single digital optical signal; extracting at least two pieces of phase information of basebands from the at least two band components; comparing at least two of the at least two extracted pieces of phase information to obtain information about a relative phase difference between at least two of the at least two extracted band components; and calculating a chromatic dispersion value for the optical transmission line; based on the information about the relative phase difference extracted from the at least two band components of different frequency optically separated from the original transmitted single digital optical signal.