Abstract: The present invention relates to optical switches in which switching occurs by changing the rotation of the plane of polarization by application of an externally applied control signal, particularly to magneto-optical switches controlling the port by which light emerges from the switch by externally-applied magnetic fields. The switches of the present invention function for randomly polarized input light, producing similarly randomly polarized light at the appropriate output port. Specific embodiments relate to 1×2 and 1×4 switches in both single pass and dual pass embodiments. Single pass embodiments are switches in which light passes through the optical components in one direction emerging at the appropriate output port depending on the desired switching. Dual pass embodiments are switches in which the light makes a forward and reverse traverse of the switch with total reflection. Dual pass switches typically reduce crosstalk without increasing the size of the switch.

Abstract: A system and method are disclosed for a user to monitor and/or override a forwarded call. Typically, the forwarded call was initially an incoming call from a caller to the user and thereafter forwarded to a remote service system, such as a remote messaging system. The system and method determine a redirecting number from which the incoming call was forwarded. The system and method then initiates a second call to the redirecting number of the user and a voice path is established connecting the forwarded call to the second call. Thereafter, the user is notified, for example, with a distinct ring at the user's telephone, of the option that the user may monitor and override the forwarded call. The system and method can also execute procedures to actuate the options elected by the user.

Abstract: The present invention relates to optical switches in which switching occurs by changing the rotation of the plane of polarization by means of an externally applied control signal, particularly to magneto-optical switches controlling the port by which light emerges from the switch by externally-applied magnetic fields. The switches of the present invention function for randomly polarized input light, producing similarly randomly polarized light at the appropriate output port. Specific embodiments relate to 1×2 and 1×4 switches in both single pass and dual pass embodiments. Single pass embodiments are switches in which light passes through the optical components in one direction emerging at the appropriate output port depending on the desired switching. Dual pass embodiments are switches in which the light makes a forward and reverse traverse of the switch with total reflection. Dual pass switches typically reduce crosstalk without increasing the size of the switch.

Abstract: The present invention relates to variable attenuation of an light beam by use of polarization rotators in which the degree of rotation of the polarization is determined by an externally-applied control signal leading to variable attenuation of the light beam under the control of the external signal. Randomly polarized light arrives at input port to the variable optical attenuator, encounters a birefringent crystal, is split into orthogonal polarization components and emerges from the crystal separated by a walk-off distance. The light beams then impinge on the surface of wave plates (polarization rotators) that are configured to cause a rotation of the plane of polarization by +45° and −45° rotation. Both light beams then impact a variable polarization rotator in which the plane of polarization is rotated through a angle that can be varied in response to an externally-applied control signal.