Abstract

In coherent optical transmission systems continuous or endless matching of the states of polarizations (SOPs) can be achieved by automatic control. The first working system was based on mechanical devices¹. Earlier proposals for LiNbO₃ exhibited a very narrow optical bandwidth^2,3, required at least two devices⁴, or failed to demonstrate automatic operation under worst case conditions⁵. We present a very robust automatic polarization control system with Ti:LiNbO₃ SOP transformers. The intensity losses remain below 0.12 dB even for worst case polarizations, with substantial multi-path reflexions present, and at high tracking speed.

© 1988 Optical Society of America