Patent ID: 8280245

Claim:
An optical sampling arrangement for evaluating the electrical field of a data-carrying optical input signal, the optical input signal exhibiting time-varying phase information φ s (t), the sampling arrangement comprising a strobe source for generating a train of gating pulses; an optical sampling element having a gating function controlled by the strobe source for transforming the optical input signal into a train of output optical sample pulses while preserving the phase information of said input optical signal; an optical source of a continuous wave (CW) local oscillator reference signal; an optical mixing element responsive to the train of output optical sample pulses from the optical sampling element and the local oscillator reference signal for combining said signals in a phase-diverse arrangement and generating a plurality of mixed sample composite output signals, comprising complex sums of components of said train of output optical sample pulses and said local oscillator reference signal; an optical detector, responsive to the plurality of mixed sample composite output signals from the optical mixing element, said optical detector for processing said plurality of mixed sample output signals to remove non-mixed terms from each signal and create electrical output signals representative of the difference between pairs of mixed sample output signal; and a signal processor for digitizing the electrical output signals and extracting therefrom a sampled version of at least one sampled version of the electrical field of the optical input signal.