LiNbO3 devices for coherent communication applications

The number of advanced coherent optical long haul transmission and subscriber systems is continuously increasing. Generally LiNbO3 devices are employed today in nearly all of these test systems for future network applications. The authors give a survey of some more matured integrated optics LiNbO3 devices. Amplitude modulators and phase modulators for external transmitter laser modulation are briefly discussed. As far as standard single mode fibers are used polarization matching devices have to be provided. For this task LiNbO3 devices for polarization control or polarization diversity reception, polarization scrambling, and polarization switching can be employed. In addition an integrated optical 90 degrees -hybrid for phase diversity reception in a homodyne system is presented.