All-optical, phase sensitive optical signal sampling

摘要

An optical sampling arrangement for high-speed measurement of the time-varying electric field of an optical input signal utilizes coherent mixing of the optical input signal with a reference laser source in a phase-diverse optical hybrid solution, followed by optical sampling of the coherently-mixed fields at the output of the optical hybrid. The generated streams of optical samples are then detected and signal processed in order to reconstruct a sampled version of the electric field of the original optical input signal.

主权项

1. An optical sampling arrangement for evaluating the complete electric field, both amplitude and phase, of an optical input signal S normally comprising optically-encoded data, the optical sampling arrangement comprising
an optical source for generating a local oscillator reference signal LO; an optical hybrid responsive to the optical input signal S and the reference signal LO for combining said S and LO signals and generating therefrom at least two composite output signals comprising complex-field sums of said S and LO signals with a known phase relationship therebetween; a strobe source for generating gating pulses at a predetermined frequency fs; at least two sampling elements, each sampling element responsive to a separate one of the at least two composite output signals from the optical hybrid and having a gating function controlled by gating pulses from the strobe source for transforming the applied composite optical signals into a train of composite signal samples, the relative phase of each of said at least two trains of composite signal samples being independent and invariant to pulse-to-pulse phase variations of said strobe source; an optical-to-electrical conversion element for transforming the at least two trains of composite signal samples from the at least two sampling elements into respective electrical streams of samples; and a signal processor for digitizing the electrical streams of samples and extracting therefrom a representation of at least one sampled version of the electric field of optical input signal S.