Polarization independent magnetooptic switches

A magnetooptic switch, comprising:

• a polarization beam splitter (PBS) optically coupled to at least one input port, a first output port, and a second output port;
• a first and a second latched rotator optically coupled to the PBS at a side opposite to the at least one input port, the first output port, and the second output port;
• a switching rotator optically coupled to the first and second latched rotators at a side opposite to the PBS, wherein the switching rotator comprises:
• a switchable Faraday rotator optically coupled to the first and second latched rotators,
• a ferrite core surrounding the Faraday rotator, and
• an electric coil surrounding the ferrite core, wherein a direction of a current supplied to the electric coil determines a direction of rotation of a polarization of a light traversing through the Faraday rotator;
• a Wollaston prism optically coupled to the Faraday rotator of the switching rotator at a side opposite to the first and second latched rotators;
• and
• a reflector optically coupled to the Wollaston prism at a side opposite to the switching rotator, wherein the reflector reflects light back through the Wollaston prism, the switching rotator, the first and second latched rotators, and the PBS, wherein the reflected light is received either by the first output port or the second output port as determined by the direction of the current supplied to the electric coil.

A magnetooptic switch, comprising:

• a polarization beam splitter (PBS) optically coupled to at least one input port, a first output port, and a second output port;
• a first, a second, and a third latched rotator optically coupled to the PBS at a side opposite to the at least one input port, the first output port, and the second output port;
• a switching rotator optically coupled to the first, second, and third latched rotators at a side opposite to the PBS, wherein the switching rotator comprises:
• a Faraday rotator optically coupled to the first, second, and third latched rotators,
• a ferrite core surrounding the Faraday rotator, and
• an electric coil surrounding the ferrite core, wherein a direction of a current supplied to the electric coil determines a direction of rotation of a polarization of a light traversing through the Faraday rotator;
• a Wollaston prism optically coupled to the switching rotator at a side opposite to the first, second, and third latched rotators;
• and
• a reflector optically coupled to the Wollaston prism at a side opposite to the switching rotator, wherein the reflector reflects light back through the Wollaston prism, the switching rotator, the second and third latched rotators, and the PBS, wherein the reflected light is received either by the first output port or the second output port as determined by the direction of the current supplied to the electric coil.

A magnetooptic switch, comprising:

• a first polarization beam splitter (PBS) optically coupled to a first input port and a second input port;
• a first latched rotator optically coupled to the PBS at a side opposite to the first and second input ports, wherein the first latched rotator receives at least one of a plurality of sub-beams from the PBS;
• a first Wollaston prism optically coupled to the PBS and optically coupled to the first rotator at a side opposite to the first PBS;
• a second latched rotator optically coupled to the first Wollaston prism at a side opposite to the first PBS;
• a switching rotator optically coupled to the first Wollaston prism at a side opposite to the second latched rotator, wherein the switching rotator comprises:
• a Faraday rotator optically coupled to the second latched rotator,
• a ferrite core surrounding the Faraday rotator, and
• an electric coil surrounding the ferrite core, wherein a direction of a current supplied to the electric coil determines a direction of rotation of a polarization of a light traversing through the Faraday rotator;
• a second Wollaston prism optically coupled to the Faraday rotator of the switching rotator at a side opposite to the second latched rotator;
• a third latched rotator optically coupled to the second Wollaston prism at a side opposite to the Faraday rotator;
• a second PBS optically coupled to the third latched rotator and the second Wollaston prism;
• and
• a first and a second output port optically coupled to the second PBS at a side opposite to the third latched rotator.

A magnetooptic switch, comprising:

• a polarization beam splitter (PBS) optically coupled to an input port;
• a first latched rotator optically coupled to the PBS;
• a polarization walk-off optically coupled to the PBS and the first latched rotator;
• and
• a switching rotator, comprising:
• a second latched rotator optically coupled to the polarization walk-off,
• a switchable Faraday rotator optically coupled o the second latched rotator,
• a ferrite core surrounding the Faraday rotator,
• an electric coil surrounding the ferrite coil, wherein a direction of a current supplied to the electric coil determines a direction of rotation of a polarization of a light traversing through the Faraday rotator, and
• a reflection layer coupled to the Faraday rotator at a side opposite to the second latched rotator, wherein the reflection layer reflects light back through the Faraday rotator, the second latched rotator, the polarization walk-off, the first latched rotator, and the PBS, wherein the reflected light is received either by a first output port or a second output port as determined by the direction of the current supplied to the electric coil.

A magnetooptic switch, comprising:

• a cubic polarization beam splitter (PBS);
• a first switching rotator optically coupled to a first face of the cubic PBS, the first switching rotator comprising:
• a first latched rotator optically coupled to the first face of the cubic PBS,
• a first switchable Faraday rotator optically coupled to the first latched rotator,
• a first ferrite core surrounding the first switchable Faraday rotator,
• a first electric coil surrounding the first ferrite coil, wherein a direction of a current supplied to the first electric coil determines a direction of rotation of a polarization of a light traversing through the first switchable Faraday rotator, and
• a first reflection layer coupled to the first switchable Faraday rotator at a side opposite to the first latched rotator, wherein the first reflection layer reflects a first light back through the first Faraday rotator, the first latched rotator, and the cubic PBS, wherein the reflected first light is received either by a first output port or a second output port as determined by the direction of the current supplied to the first electric coil;
• and
• a second switching rotator optically coupled to a second face of the cubic PBS adjacent to the first face, the second switching rotator comprising:
• a second latched rotator optically coupled to the second face of the cubic PBS,
• a second switchable Faraday rotator optically coupled to the second latched rotator,
• a second ferrite core surrounding the second switchable Faraday rotator,
• a second electric coil surrounding the second ferrite coil, wherein a direction of a current supplied to the second electric coil determines a direction of rotation of a polarization of a light traversing through the second switchable Faraday rotator, and
• a second reflection layer coupled to the second switchable Faraday rotator at a side opposite to the second latched rotator, wherein the second reflection layer reflects a second light back through the second switchable Faraday rotator, the second latched rotator, and the cubic PBS, wherein the reflected second light is received either by the second output port or the first output port as determined by the direction of the current supplied to the second electric coil.

A magnetooptic switch, comprising:

• a special shaped polarization beam splitter (PBS);
• and
• a switching rotator optically coupled to the special shaped PBS, the switching rotator comprising:
• a latched rotator optically coupled to the special shaped PBS,
• a switchable Faraday rotator optically coupled to the latched rotator,
• a ferrite core surrounding the switchable Faraday rotator,
• an electric coil surrounding the ferrite coil, wherein a direction of a current supplied to the electric coil determines a direction of rotation of a polarization of a light traversing through the switchable Faraday rotator, and
• a reflection layer coupled to the switchable Faraday rotator at a side opposite to the latched rotator, wherein the reflection layer reflects light back through the switchable Faraday rotator, the latched rotator, and the special shaped PBS, wherein the reflected light is received either by a first output port or a second output port as determined by the direction of the current supplied to the electric coil.

A method for switching an unpolarized light, comprising the steps of:

• (a) splitting the unpolarized light into a first sub-beam with a first polarization direction and a second sub-beam with a second polarization direction;
• (b) rotating either the first or the second sub-beam, such that the polarization directions of the first and second sub-beams are parallel, wherein the rotating is performed by a switching rotator, wherein the switching rotator comprises:
• a switchable Faraday rotator for rotating the polarization directions of the first and second sub-beams,
• a ferrite core surrounding the switchable Faraday rotator, and
• an electric coil surrounding the ferrite core, wherein a direction of a current supplied to the electric coil determines a direction of rotation of the polarization of the first and second sub-beams;
• (c) displacing the first and second sub-beams;
• (d) combining the first and second sub-beams in the unpolarized light;
• and
• (e) outputting the unpolarized light either at a first output port or a second output port based upon the direction of the current supplied to the electric coil.

A system, comprising:

• an optical network, the optical network comprising:
• at least one input port for providing an optical signal with an arbitrary polarization,
• a first output port, and
• a second output port;
• and
• a magnetooptic switch, comprising:
• a PBS optically coupled to at least one input port,
• a first and a second latched rotator optically coupled to the PBS at a side opposite to the at least one input,
• a switching rotator optically coupled to the first and second latched rotators at a side opposite to the PBS, wherein the switching rotator comprises:
• a switchable Faraday rotator optically coupled to the first and second latched rotators,
• a ferrite core surrounding the switchable Faraday rotator, and
• an electric coil surrounding the ferrite core, wherein a direction of a current supplied to the electric coil determines a direction of rotation of a polarization of a light traversing through the switchable Faraday rotator;
• a Wollaston prism optically coupled to the switchable Faraday rotator of the switching rotator at a side opposite to the first and second latched rotators, and
• a reflector optically coupled to the Wollaston prism at a side opposite to the switching rotator, wherein the reflector reflects light back through the Wollaston prism, the switching rotator, the first and second latched rotators, and the PBS, wherein the reflected light is received either by the first output or the second output as determined by the direction of the current supplied to the electric coil.

A system, comprising:

• a plurality of switches optically coupled to each other, wherein at least one of the plurality of switches comprises:
• a PBS optically coupled to an input port,
• a first and a second latched rotator optically coupled to the PBS at a side opposite to the input port,
• a switching rotator optically coupled to the first and second latched rotators at a side opposite to the PBS, wherein the switching rotator comprises:
• a switchable Faraday rotator optically coupled to the first and second latched rotators,
• a ferrite core surrounding the switchable Faraday rotator, and
• an electric coil surrounding the ferrite core, wherein a direction of a current supplied to the electric coil determines a direction of rotation of a polarization of a light traversing through the switchable Faraday rotator,
• a Wollaston prism optically coupled to the switchable Faraday rotator of the switching rotator at a side opposite to the first and second latched rotators, and
• a reflector optically coupled to the Wollaston prism at a side opposite to the switching rotator, wherein the reflector reflects light back through the Wollaston prism, the switching rotator, the first and second latched rotators, and the PBS, wherein the reflected light is received either by a first output or a second output as determined by the direction of the current supplied to the electric coil;
• and
• an optical signal traversing through at least one of the plurality of switches.