Optical switch and optical routing method and system

Patent metadata

Field	Value
Publication number	US-11729535-B2
Application number	US-202117995219-A
Country	US
Kind code	B2
Filing date	Mar 10, 2021
Priority date	Mar 30, 2020
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

An optical switch is proposed, for routing an optical transmission signal according to an optical control signal, including one or more optical control ports; three or more optical transmission ports; a light director; and a thermally driven light mill; where the light mill and the light director are arranged with respect to each other, to the one or more control ports and to the three or more transmission ports such that: illumination of a respective one of the one or more control ports by a control beam carrying the control signal drives the light mill to rotate towards a respective position in which the light director is arranged so as to direct a transmission beam carrying the transmission signal, entering the switch via a respective one of the transmission ports, to exit the switch via a respective other of the transmission ports.

First claim

The invention claimed is:

1. An optical switch for routing an optical transmission signal according to an optical control signal, the optical switch comprising:
one or more optical control ports, and three or more optical transmission ports, wherein:
each optical control port can be an optical transmission port,
each optical transmission port can be an optical control port, and
each optical control port and each optical transmission port can be distinct;

three or more optical transmission ports;
a light director; and
a thermally driven light mill;
wherein the thermally driven light mill and the light director are arranged with respect to each other, to the one or more optical control ports and to the three or more optical transmission ports such that:
illumination of a respective one of the one or more optical control ports by a control beam carrying the optical control signal drives the thermally driven light mill to rotate towards a respective position in which the light director is arranged so as to direct a transmission beam carrying the optical transmission signal, entering the optical switch via a respective one of the three or more optical transmission ports, to exit the optical switch via a respective other one of the three or more optical transmission ports.

2. The optical switch of claim 1 , wherein the control beam originates from a laser.

3. The optical switch of claim 1 , wherein at least one of:
a side of a vane of the thermally driven light mill arranged to be illuminated by the control beam has a higher optical absorptance than an optical absorptance of an opposing side of the vane; or
a side of a vane of the thermally driven light mill arranged to be illuminated by the control beam and an opposing side of the vane are shaped such that, over a range of rotation of the thermally driven light mill from an initial position in which the thermally driven light mill resides immediately preceding illumination of the respective one of the one or more optical control ports by the optical control signal, to the respective position, the side of the vane illuminated by the control beam receives a greater quantity of radiant energy from the control beam than the opposing side of the vane.

4. The optical switch of claim 1 , wherein the three or more optical transmission ports comprise a single optical input port and a plurality of optical output ports, the thermally driven light mill and the light director being arranged with respect to each other, to the one or more optical control ports and to the three or more optical transmission ports such that, for each of the optical output ports:
illumination of a respective one of the one or more optical control ports by the control beam drives the thermally driven light mill to rotate towards a respective position in which the light director is arranged so as to direct the transmission beam, entering the optical switch via the optical input port, to exit the optical switch via that optical output port.

5. The optical switch of claim 1 , wherein the optical transmission ports comprise a plurality of optical input ports and a single optical output port, the thermally driven light mill and the light director being arranged with respect to each other, to the one or more optical control ports and to the three or more optical transmission ports such that, for each of the plurality of optical input ports:
illumination of a respective one of the one or more optical control ports by the control beam drives the thermally driven light mill to rotate towards a respective position in which the light director is arranged so as to direct the transmission beam, entering the switch via that optical input port, to exit the switch via the optical output port.

6. The optical switch of claim 5 , configured such that, for each of the optical input ports, the control beam and the transmission beam are derived from a common source beam.

7. The optical switch of claim 6 , wherein, for each of the optical input ports, the one of the one or more optical control ports illuminated by the optical control signal is each of the optical input ports, the source beam itself serving as both the transmission beam and the control beam.

8. The optical switch of claim 6 , further comprising, for each of the optical input ports, an optical splitter arranged to split the source beam into the transmission beam and the control beam.

9. The optical switch of claim 5 , wherein the light director is arranged to rotate with the thermally driven light mill.

10. The optical switch of claim 9 , wherein the light director comprises a mirror.

11. The optical switch of claim 10 , wherein a surface of the thermally driven light mill on which the optical control signal is incident is partially reflective, thereby providing the mirror.

12. The optical switch of claim 10 , wherein the mirror is arranged to reflect light incident substantially on an axis of rotation of the thermally driven light mill such that light is incident on the optical output port along substantially a same line regardless of the one of the optical input ports the light originated from.

13. The optical switch of claim 1 , wherein there is only one optical control port, the optical switch further comprising an optical control signal source configured to illuminate the optical control port according to a computer-implemented scheduling method.

14. An optical routing system comprising:
the optical switch of claim 13 and
a computing device arranged to implement the computer-implemented scheduling method.

15. The optical switch of claim 1 , further comprising one or more stays each arranged to prevent rotation of the thermally driven light mill beyond at least one of the respective positions.

16. The optical switch of claim 1 , further comprising a biasing element, the thermally driven light mill being coupled to the biasing element such that:
the thermally driven light mill is biased towards an equilibrium position different from any of the respective positions, wherein the equilibrium position can be an off position; or
the thermally driven light mill is biased towards one of the respective positions.

17. The optical switch of claim 1 , further comprising a housing which encloses the thermally driven light mill, the housing comprising an aperture configured for partial evacuation of fluid surrounding the thermally driven light mill.

18. A method of routing an optical transmission signal, the method comprising illuminating one of the optical transmission ports of the optical switch of claim 1 with the optical transmission signal.

19. The method of claim 18 , wherein the optical switch has only one optical control port and further comprises an optical control signal source configured to illuminate the one optical control port according to a computer-implemented scheduling method, the method further comprising:
illuminating the one optical control port for one of d predetermined durations, each of the predetermined durations corresponding to a rotation of the thermally driven light mill from a first one of the respective positions to a respective one of the other such respective positions, wherein d is equal to p−1, p being a number of the optical transmission ports.

Assignees

• British Telecomm

Inventors

• Menchetti Marco

Classifications

• H04Q3/526 Primary

  Optical switching systems · CPC title

• G02B26/0866

  the reflecting means being moved or deformed by thermal means · CPC title

• H04Q11/0005

  Switch and router aspects · CPC title

• H04Q2011/0015

  using splitting combining · CPC title

• H04Q2011/0026

  using free space propagation (e.g. lenses, mirrors) · CPC title