Patent ID: 7528360
Filing Date: 2009-05-05
Classification: G02B,G02F,H04J

Abstract:
1. A polarization stabilizing device for stabilizing the state of polarization of optical radiation, comprising: 1) a polarization transformer comprising: 2) a detecting system capable of generating a monitor signal representative of an optical power of a polarized portion of the optical radiation output from the second variable polarization rotator; and 3) a controller capable of receiving said monitor signal from the detecting system and supplying first and second control signals responsive to said monitor signal, respectively, to the first and second variable polarization rotators so as to control said first and second variable phase retardations, wherein the controller is configured: to set the second control signal so as to maintain the polarization azimuth of the optical radiation output from the second variable polarization rotator at a value of about +45 degrees or −45 degrees to said defined azimuth; and, in case the second variable phase retardation reaches a predefined threshold value equal to about k180+2δ degrees, wherein k is an integer and δ is said arbitrary value expressed in degrees, to set the first control signal so as to switch the first variable phase retardation between first and second values.