Abstract:

In this paper, optical communication using quaternary differential polarization shift keying is proposed, which is immune to random fluctuation in the state of polarization (SOP) of the optical signals propagating through a single-mode fiber. Relationship is established in the transmitter using differential coding between the difference in SOPs of the optical signals in consecutive symbol periods and the input symbol of the differential encoder. In the receiver, Stokes vectors are extracted from the optical signals in two consecutive symbol periods. Dot product of the two vectors is then obtained so that the transmitted sequence recovered. The dot multiplication can effectively eliminate the effect of random fluctuation in the SOPs of optical signals on the performance of communication system.

Key words: differential coding, dot multiplication, SOP

differential polarization shift keying (DPolSK)