High power optical switch

Patent metadata

Field	Value
Publication number	US-9470953-B2
Application number	US-201314404821-A
Country	US
Kind code	B2
Filing date	May 24, 2013
Priority date	May 24, 2012
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

An optical switch ( 10 ) is capable of routing a high-power beam incident at one or more input ports ( 12 ) of the optical switch to either of two or more output ports ( 14,16 ), the optical switch comprising: at least one switching stage, each of the at least one switching stages comprising: a switchable high-power liquid crystal (LC) half-wave plate (HWP), oriented with its fast axis at 45° to an input polarization direction such that in response to an incident polarized laser beam provided to said switchable high-power liquid crystal, half-wave plate, said HWP acts as a polarization rotator; and a polarizing beam splitter (PBS) disposed in an optical path to intercept light signals output from said switchable high-power liquid crystal (LC) half wave plate (HWP).

First claim

What is claimed is:

1. An optical switch capable of routing an optical beam incident at one or more input ports of the optical switch to either of two or more output ports, the optical switch comprising:
at least one switching stage, each of the at least one switching stages comprising:
a switchable high-power liquid crystal (LC) half-wave plate (HWP), oriented with its fast axis at 45° to an input polarization direction such that in response to an incident polarized laser beam provided to said switchable high-power liquid crystal, half-wave plate, said HWP acts as a polarization rotator;
a polarizing beam splitter (PBS) disposed in an optical path to intercept light signals output from said switchable high-power liquid crystal (LC) half-wave plate (HWP); and
a tip/tilt/focus optical phased array (TTFOPA) disposed at an output of the PBS, wherein the TTFOPA comprises two optical phased arrays with their steering axis in different directions.

2. The optical switch of claim 1 further comprising a plurality of switching stages cascade coupled to provide the optical switch having at least one input port and a plurality of output ports.

3. The optical switch of claim 1 wherein:
in response to said HWP being in a first state, said HWP is capable of converting an optical signal having a first polarization to an optical signal having a second, different polarization; and
in response to said HWP being in a second different state, said HWP operates as a null polarization operator.

4. The optical switch of claim 1 wherein said PBS is provided as one of:
a beam splitting cube; or
a polarizing plate.

5. The optical switch of claim 1 wherein said PBS nominally passes light having a first polarization and reflects light having a second different s polarization and when the HWP is on, light having the first polarization is passed through the switching stage to a first output port of the switching stage and when the HWP is off, the input light having the first polarization is converted to the second different s polarization and reflected to a second output port the switching stage.

6. The optical switch of claim 1 further comprising:
a collimating lens disposed at an output of at least one of said at least one switching stages.

7. The optical switch of claim 6 where said collimating lenses are provided to nominally focus the output beams for matching of the fiber mode.

8. The optical switch of claim 6 further comprising a control loop circuit disposed on the first output port of a first switching stage, said control loop circuit coupled between the output of the first switching stage and the TTFOPA.

9. The optical switch of claim 8 wherein said control loop circuit comprises:
a directional coupler; and
an SPGD processor wherein said directional coupler couples power from a fiber coupled to the output port of the stage and provides the coupled signal to said SPGD processor and wherein said SPGD processor adjusts the TTFOPA angles and focal power in two dimensions for maximum power coupled into the fiber.

10. The optical switch of claim 6 further comprising a plurality of switching stages cascade coupled to provide the optical switch having at least one input port and a plurality of output ports.

11. The optical switch of claim 10 further comprising a control loop circuit coupled between the output of each switching stage and the TTFOPA within said switching stage.

12. An optical system comprising:
a plurality of unpolarized laser diode pumps;
first and second phased arrays; and
an optical switch coupled between said plurality of unpolarized laser diode pumps and said first and second phased arrays, wherein said optical switch is capable of switching said plurality of diode pumps between the first and second phased arrays wherein said optical switch comprises:
at least one switching stage, each of the at least one switching stages comprising:
a switchable high-power liquid crystal (LC) half-wave plate (HWP), oriented with its fast axis at 45° to an input polarization direction such that in response to an incident polarized laser beam provided to said switchable high-power liquid crystal, half-wave plate, said HWP acts as a polarization rotator; and
a polarizing beam splitter (PBS) disposed in an optical path to intercept light signals output from said switchable high-power liquid crystal (LC) half-wave plate (HWP).

13. The system of claim 12 wherein said switch is configured such that pump N is routed to the Nth aperture of either the first array or the second array.

14. An optical switch that can route a high-power beam incident at one or more input ports to either of two or more output ports wherein an incident polarized laser beam is passed through a switchable high-power liquid crystal (LC) half-wave plate (HWP), oriented with its fast axis at 45° to the input polarization direction, followed by a polarizing beam splitter (PBS), which, when so adjusted, the HWP acts as a polarization rotator, and further followed by a tip/tilt/focus optical phased array (TTFOPA) disposed at an output of the PBS, wherein the TTFOPA comprises two optical phased arrays with their steering axis in different directions.

15. The switch of claim 14 wherein:
when the HWP is in its “off” state converts p polarization to s and in its “on” state it is a null polarization operator; and
wherein the PBS is one of a beam splitting cube or a window coated with an appropriate dielectric thin film, an arrangement known as a polarizing plate, said plate oriented at the proper angle to effect the same polarization discrimination as a PBS.

16. The switch of claim 14 wherein the PBS nominally passes p polarized light and reflects s polarized light and when the HWP is ‘on’, p polarized input light is passed through this switching stage to a first output port and when the HWP is ‘off’ the input p polarized light is converted to s and reflected to a second output port.

17. An optical switch capable of routing a high-power beam incident at one or more input ports of the optical switch to either of two or more output ports, the optical switch comprising:
at least one switching stage, each of the at least one switching stages comprising:
a switchable high-power liquid crystal (LC) half-wave plate (HWP), oriented with its fast axis at 45° to an input polarization direction such that in response to an incident polarized laser beam provided to said switchable high-power liquid crystal, half-wave plate, said HWP acts as a polarization rotator;

a polarizing beam splitter (PBS) disposed in an optical path to intercept light signals output from said switchable high-power liquid crystal (LC) half-wave plate (HWP);
a collimating lens disposed at an output of at least one of said at least one switching stages; and
at the output of each of said at least one switching stages having a collimating lens coupled thereto, a tip/tilt/focus optical phased array (TTFOPA) disposed between an output of a PBS of each of said at least one switching stages and said respective collimating lens, wherein the TTFOPA comprises two optical phased arrays with approximately perpendicular steering axes.

18. The optical switch of claim 17 further comprising a plurality of switching stages cascade coupled to provide the optical switch having at least one input port and a plurality of output ports.

19. The optical switch of claim 17 wherein:
in response to said HWP being in its “off” state, said HWP is capable of converting an optical signal having a first polarization to an optical signa

Assignees

• Raytheon Co

Inventors

• Smith Irl W
• Dorschner Terry A

Classifications

• G02F1/292

  by controlled diffraction or phased-array beam steering (controlled diffraction for optical switching G02F1/31) · CPC title

• G02B6/3544

  2D constellations, i.e. with switching elements and switched beams located in a plane · CPC title

• H04Q2011/0035

  using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical · CPC title

• G02F1/133385 Primary

  with cooling means, e.g. fans · CPC title

• G02B6/3542

  Non-blocking switch, e.g. with multiple potential paths between multiple inputs and outputs, the establishment of one switching path not preventing the establishment of further switching paths · CPC title