Ultrafast photonic intensity integrator.

A method for ultrafast photonic time-intensity integration of an arbitrary temporal waveform is, for the first time to our knowledge, proposed and demonstrated. The introduced intensity-integration concept is based on the superposition of mutually incoherent, continuously-time-delayed replicas of the optical intensity waveform to be processed. This idea is practically implemented using optical intensity modulation of the input waveform with a rectangularlike incoherent energy spectrum distribution followed by linear dispersion. The key design specifications of the proposed integration scheme are derived and discussed. Proof-of-concept experiments are performed demonstrating accurate integration of several duration-limited microwave and optical intensity waveforms with time features from the picosecond to the subnanosecond range.