초록 ▼

A state-of-polarization (SOP) control system (10) uses a SOP controller (28) that is responsive to a CPU (24) to perform endless and complete polarization signal detection for a fiber optic communication system. The SOP controller (28) comprises liquid crystal variable optical retarders (40, 42 and

A state-of-polarization (SOP) control system (10) uses a SOP controller (28) that is responsive to a CPU (24) to perform endless and complete polarization signal detection for a fiber optic communication system. The SOP controller (28) comprises liquid crystal variable optical retarders (40, 42 and 44) that adjust the polarization state of local optical signal (36) in response to voltages provided by the CPU (24). The CPU (24) adjusts the voltage applied to the retarders (40, 42, and 44) separately in response to the magnitude of an interference signal (70), which corresponds to the degree to which the polarization of the local optical signal (36) and an input optical signal (12) are different.

대표청구항 ▼

A state-of-polarization control system for an optical system in which a detector develops a difference signal that is indicative of a difference between a first polarization state of a first optical signal and a second polarization state of a second optical signal, comprising: polarization control m

A state-of-polarization control system for an optical system in which a detector develops a difference signal that is indicative of a difference between a first polarization state of a first optical signal and a second polarization state of a second optical signal, comprising: polarization control means including first, second, and third retarding devices for controlling the difference between the first polarization state of the first optical signal and the second polarization state of the second optical signal; and signal processing means responsive to the difference signal for computing polarization data to which the retarding devices of the polarization control means respond to minimize the difference between the first and second polarization states, the system including in a normal mode of operation during which the first retarding device provides a retardance yz, and the second retarding device provides a retardance qp=(4n1±1)p/2, where n1 is any integer, whenever n2pyz2+1)p2 is any integer.