Dual closed loop for laser power control

An optic signal generator power control system comprising:

• a laser driver configured to receive a data signal, and responsive to a modulation control signal, and a bias control signal, process the data signal to a format suitable for driving an optic signal generator to generate an optic signal that represents the data signal;
• a monitor photodiode configured to receive the optic signal and generate a monitor photodiode signal, the monitor photodiode signal comprising the data signal and errors introduced by the monitor photodiode;
• a modulation control path configured to process a monitor photodiode signal and a reference signal, both the monitor photodiode signal and the reference signal processed by at least one filter and at least one mixer that are in the modulation control path, the processing generating a modulation control signal;
• and,
• a bias control path configured to process the monitor photodiode signal and the reference signal, both the monitor photodiode signal and the reference signal processed by at least one filter and at least one average weighting module that are in the bias control path, the processing generating a modulation control signal, wherein the bias control path and the modulation control path reduce or eliminate an effect of the error in the monitor photodiode signal.

A method for processing a monitor photodiode signal to remove errors in the monitor photodiode signal as compared to a corresponding data signal, the method comprising:

• receiving the monitor photodiode signal;
• receiving a reference signal;
• processing the monitor photodiode signal and the reference signal with one or more transimpedance amplifiers to generate a monitor photodiode current signal and a reference current signal;
• processing the monitor photodiode current signal and the reference current signal with a modulation control path to generate a modulation current control signal, the modulation control path including at least one mixer configured to generate the power of the monitor photodiode current signal and the power of the reference current signal;
• processing the monitor photodiode current signal and the reference current signal with a bias control path to generate a bias current control signal, the bias control path including at least one average weighting module configured to determine an average value for the monitor photodiode current signal and the power of the reference current signal;
• a feedback path configured to provide the modulation current control signal and the bias current control signal to a driver to control the modulation current and bias current that the driver uses to drive an optic signal generator.