A circuit, optical transceiver and/or methods for using the same may be useful for determining average power, extinction ratio, and/or modulation amplitude when monitoring an optical transceiver and/or optical network. The circuit generally comprises a photodiode configured to generate a first current responsive to an optical signal, a current mirror coupled to a first terminal of the photodiode, and a detector coupled to a second terminal of the photodiode. The current mirror is configured to produce a second current equal to or proportional to the first current, and the detector is configured to determine a power or amplitude of the optical signal. Further, the present scheme may communicate information using a low speed signal superimposed on or combined with the relatively high speed optical signal.