Patent ID: 7324758

Claim:
An optical dispersion monitoring apparatus for monitoring dispersion based on a waveform of an input optical signal, comprising: a characteristic amount detecting section selectively detecting a physical amount corresponding to a location where waveform distortion occurring depending on dispersion appears distinctively in the waveform of said input optical signal; and a dispersion information extracting section extracting information related to the dispersion which has occurred in said optical signal, based on a comparison between the physical amount detected in said characteristic amount detecting section and a reference value indicated by a reference signal, to output the information, wherein said characteristic amount detecting section includes: a light receiving section converting said input optical signal into an electrical signal; and a signal transition position detecting section detecting the voltage level corresponding to at least one of a rising edge and a falling edge of a waveform of the electrical signal converted in said light receiving section, and wherein said dispersion information extracting section compares the reference value indicated by the reference signal with the voltage level detected in said signal transition position detecting section, and outputs a signal corresponding to the comparison result as dispersion information; and wherein said signal transition position detecting section detects the voltage level corresponding to crossing points in an eye pattern of the electrical signal converted in said light receiving section.