Ultrafast optical signal measurement using optoelectronic techniques

A novel ultrafast optical signal measurement technique is proposed that use s a fast photodetector and electrooptic (EO) sampling. The technique can sa tisfy three requirements for the measurement: large bandwidth, high sensiti vity, and polarization independence. The measurement systems are demonstrat ed using two kinds of EO sampling configurations. One system uses direct EO sampling. It affords a larger bandwidth. The system can discern 100-Gbit s (-1) return-to-zero (RZ) optical pulse-pattern signals with an on-off ratio of 22 dB. The other system uses a waveguide intensity modulator in EO samp ling. It affords higher sesitivity and can measure an 80-Gbit s(-1) RZ opti cal eye diagram. It is theoretically expected that the sensitivity of our s ystem is higher than that of the all-optical technique.