Bias-based Mach-Zehnder modulation (MZM) systems

A method for tuning a Mach-Zehnder modulation (MZM) system, the method comprising:

• providing an optical input signal into a Mach-Zehnder modulator to provide an intensity-modulated optical output signal at an output;
• controlling a set of switches to modulate the phase of the optical input signal to tune the Mach-Zehnder modulator based on a bias voltage;
• generating a detection voltage associated with an optical power of the intensity-modulated optical output signal;
• determining a peak voltage associated with the detection voltage;
• comparing the peak voltage with a reference voltage to determine an extinction ratio associated with the optical power of the intensity-modulated optical output signal;
• and
• adjusting an amplitude of the bias voltage;
• iteratively increasing the bias voltage based on the comparison;
• detecting that the peak voltage is approximately equal to the reference voltage;
• and
• upon detection, continue to iteratively increasing the bias voltage a predetermined number of iterations to substantially maximize the extinction ratio.

A bias-based Mach-Zehnder modulation (MZM) system comprising:

• a Mach-Zehnder modulator to receive and split an optical input signal and to provide an intensity-modulated optical output signal based on a high-frequency data signal to modulate a relative phase of the split optical input signal to transmit data and based on a bias voltage provided via a set of switches to modulate the relative phase of the split optical input signal to tune the Mach-Zehnder modulator;
• and
• a bias feedback controller comprising:
• a peak voltage detector to detect a peak voltage associated with a peak amplitude of a detection voltage associated with an amplitude of the intensity-modulated output signal;
• a voltage comparator to compare the peak voltage with a reference voltage to measure an extinction ratio associated with an optical power of the intensity-modulated optical output signal;
• and
• a bias controller to independently set an amplitude of the bias voltage and the reference voltage in response to the comparison of the peak voltage with the reference voltage,
• wherein the bias controller is further configured to iteratively increase the bias voltage based on the comparison until the bias controller detects that the peak voltage is approximately equal to the reference voltage, and, upon detection, continue to iteratively increase the bias voltage a predetermined number of iterations to substantially maximize the extinction ratio.