Method and apparatus for pulse generation and adaptive pulse generation for optical communications

An apparatus, comprising:

• a photodiode configured to receive an optical pulse having a first spectral component, a second spectral component and a third spectral component, the second spectral component and the third spectral component being based on a clock frequency, the photodiode configured to send a first signal having an amplitude and a spectral component with the clock frequency;
• a filter coupled to the photodiode, the filter having a spectral response associated with the clock frequency;
• and
• a detector coupled to the filter, the detector configured to send an error signal based on the amplitude of the first signal.

A method for measuring an optical pulse received from a transmission link, comprising:

• detecting a signal based on an optical pulse having a first spectral component, a second spectral component and a third spectral component, the second spectral component and the third spectral component being based on a clock frequency;
• filtering the detected signal to produce a first signal associated with the clock frequency;
• and
• detecting an amplitude of the first signal.

An apparatus, comprising:

• a tunable delay device configured to receive a first amplitude portion of an optical signal;
• an optical hybrid coupled to the tunable delay device, the optical hybrid configured to receive a second amplitude portion of the optical signal;
• a detector coupled to the tunable delay device;
• and
• a processor coupled to the detector, the processor being configured to calculate a pulse width of the optical signal based on an autocorrelation of the first amplitude portion of the optical signal and the second amplitude portion of the optical signal component.

A method for measuring an optical signal received from a transmission link, the optical signal including a plurality of optical pulses having an estimated pulse width, comprising:

• splitting the optical signal into a first amplitude portion associated with a first optical path and a second amplitude portion associated with a second optical path;
• delaying each pulse from the plurality of pulses associated with the first amplitude portion of the optical signal with an increasing amount of delay corresponding to a fraction of the estimated pulse width of the optical pulse;
• combining the first amplitude portion of the optical signal with the second amplitude portion of the optical signal using an optical hybrid;
• detecting an overlap between the first amplitude portion of the optical signal and the second amplitude portion of the optical signal;
• and
• determining a pulse width of a pulse from the plurality of optical pulses for the optical signal based on the detected overlaps between the first amplitude portion of the optical signal and the second amplitude portion of the optical signal for the range of delays.

A method for measuring an optical signal received from a transmission link, the optical signal including a plurality of optical pulses having an estimated pulse width, comprising:

• introducing a first dispersion into a first portion of an optical signal on a first optical path;
• introducing a second dispersion into a second portion of the optical signal on a second path, the first dispersion having its own amplitude and sign, the second dispersion having its own amplitude and sign, the amplitude of the first dispersion being substantially equal to the amplitude of the second dispersion, the sign of the first dispersion being opposite of the sign of the second dispersion;
• and
• detecting the first portion of the optical signal after the introducing of the first dispersion and the second portion of the optical signal after the introducing of the second dispersion to produce a balanced-detected signal.

A method for adaptively tuning a pulse generator sending an optical pulse over a transmission link, comprising:

• sending a plurality of testing signals each being associated with its own dithered value from a plurality of dithered values, each dithered value from the plurality of dither values being associated with at least one from a center value and an offset value;
• receiving a plurality of optical pulses each being uniquely associated with an testing signal from the plurality of testing signals;
• detecting a plurality of modulation signals based on the plurality of optical pulses, each modulation signal from the plurality of modulation signals having its own amplitude and a spectral component with a modulation frequency;
• and
• calculating a new center value based on the amplitude of modulation signals.