In accordance with one embodiment of the present disclosure, a system for optical signal dispersion and parameter monitoring comprises a tunable filter configured to filter a portion of one channel of an optical signal. The system comprises a polarization beam splitter configured to split the portion into first and second polarization beams and further comprises first and second photodetectors configured to respectively convert the first and second polarization beams into first and second electrical signals. Also, the system comprises a control unit configured to determine optical dispersion in the portion based on the first and second electrical signals when the portion includes a test signal. The control unit is configured to determine optical signal parameters of the portion such as channel power, channel wavelength, optical spectrum analysis (OSA) and optical signal-to-noise ratio (OSNR) based on the first and second electrical signals when the portion does not include the test signal.