In-band optical signal-to-noise ratio measurement

摘要

Various embodiments relate to an in-band measurement of the optical signal-to-noise ratio (OSNR) of an optical signal in an optically-amplified transmission system. A demodulation device may tap a transmission fiber to receive an optical signal containing a low-frequency signal. A filter may implement first and second passbands to filter portions of an optical channel in the optical signal. Once the filtered channel is converted to first and second target electrical signals, a measurement circuit may take measurements of DC and AC components for each of the target electrical signals. Based on measurements of the two target electrical signals, the demodulation device may calculate the OSNR as a function of the DC and AC components, or as a function of the adjustment factors between first and second passbands of the optical channel represented by the first and second target electrical signals.

主权项

1. A method for in-band measurement of an optical signal-to-noise ratio (OSNR) by a demodulation device, the method comprising:
receiving an optical payload containing a low-frequency signal; filtering a first passband of the optical payload in an optical channel; converting the first passband-filtered optical signal to a first target electrical signal; measuring DC and AC components of the first target electrical signal; filtering a second passband of the optical payload within a bandwidth of the optical channel; converting the second passband-filtered optical signal to a second target electrical signal; measuring DC and AC components of the second target electrical signal; and determining the OSNR of the optical channel, wherein the OSNR of the optical channel is based on a first ratio between the DC components of the first and second target electrical signals and a second ration between the AC components of the first and second target electrical signals.