Retrieve and preserve arbitrary polarization states endlessly at uniform high speed

Abstract

We put forward a novel scheme based on open-loop polarization control (OLPC) to retrieve and preserve arbitrary polarization states endlessly at uniform high speed, with average error of ~0.035 rad and time cost less than 300 μs, which breaks through the limitation of those depend on close-loop polarization control (CLPC). Utilizing perfect modules we build an experimental OLPC system and establish its matrix model with control programme. Results show that the two-unit PC always has blind zone which can not be suppressed to zero, and the blind area centres exactly on the principal state of polarization (PSP) of the second unit. Then we start the third unit to retrieve the SOP from the blind area thus we achieve arbitrary SOPs on the Poincaré sphere endlessly. Subsequently, we demonstrate the great capacity of the OLPC scheme by successfully carrying on retrieving and preserving arbitrary SOPs disturbed by a polarization scrambler, while for sudden and huge disturbance it still shows quite robust and extremely strong. As a result, we fulfill the scheme in practical case of polarization encoded communication system with various environmental disturbance, and further reveal its prominent performance on improvement of signal quality and preservation of reliable communications, which manifests that it is suitable for field applications where exists much disturbance.