Patent ID: 7042629

Claim:
A linear optical signal sampler apparatus for measuring temporal samples of a modulated optical signal (MOS), the linear optical signal sampler apparatus comprising a pulsed optical signal (POS) having energy in the same polarization as the MOS and operable at a pulse rate equal to a fraction of the modulation rate of the MOS; a hybrid having a first input for receiving the MOS and a second input for receiving the POS, the hybrid combining the MOS and POS to produce temporal quadrature samples S A and S B of the intefference of the electrical fields of the MOS with the POS, the optical signals corresponding to the S A quadrature samples being outputted at a first and second outputs, and the optical signals corresponding to the S B quadrature samples being outputted at a third and fourth outputs; a balanced photodetector apparatus (BDA,BDB) coupled to the first, second, third, and fourth outputs for detecting and generating analog electrical signal representations of the S A and S B quadrature samples; a sampling analog to digital (A/D) converter apparatus for sampling and generating digital representations of S A and S B quadratures samples, the sampling A/D converter apparatus being synchronized to the pulses of the POS; and a processor for compensating for optical and electrical signal handling imperfections in the hybrid, balanced detectors, and A/D converters and for measuring temporal signal samples by generating a demodulated sampled data pulse from the quadratures samples S A and S B .