Method and system for optical switching with integrated polarization diversity control

Abstract

A method and system for optical switching with integrated polarization diversity control includes a beam shifter for receiving an input beam and splitting the input beam into a first beam and a second beam having linear polarization. The first light beam and the second light beam may be received on a liquid crystal cell that may rotate the first light beam or the second light beam such that the two light beams have the same polarization after passing through the liquid crystal cell. Based on the polarization, the output beam may be exchanged to a port.

Description

Technical Field

[0001] The present invention generally relates to a method and system for optical switching with integrated polarization diversity control. Background Art

[0002] Aspects of the present invention relate to a method and system for optical switching with integrated polarization diversity control. Conventional solutions for optical switching with integrated polarization diversity control can present various problems. Conventional systems and methods for optical switching with integrated polarization diversity control can be costly, cumbersome, and / or inefficient.

[0003] The limitations and disadvantages of conventional systems and methods will become apparent to those skilled in the art by comparing such methods with some aspects of the present methods and systems as set forth in the remainder of this disclosure with reference to the accompanying figures. Summary of the Invention

[0004] Shown in at least one of these figures and / or described in connection therewith, and more fully set forth in the claims, are waveguides and methods of forming such waveguides.

[0005] These and other advantages, aspects and novel features of the present disclosure, as well as details of illustrated embodiments thereof, will be more fully understood from the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The various features and advantages of the present invention may be more readily understood by reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like structural elements.

[0007] Figure 1 is a block diagram illustrating an optical processing system according to some embodiments of the present disclosure.

[0008] Figure 2A It further illustrates some embodiments of the present disclosure. Figure 1 Schematic diagram of an optical processing system.

[0009] Figure 2B Further illustrating the switching in different spatial output directions according to some embodiments of the present disclosure Figure 2A .

[0010] Figure 2C Exemplary electrode arrangements for LC cell / pixel arrays according to various embodiments of the present disclosure are shown.

[0011] Figure 3 is a flowchart illustrating an optical processing method according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0012] The following discussion provides various examples of optical devices and methods. Such examples are non-limiting, and the scope of the appended claims should not be limited to the specific examples disclosed. In the following discussion, the terms "example" and "for example" are non-limiting.

[0013] The accompanying drawings illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the present disclosure. In addition, the elements in the drawings are not drawn to scale. For example, the dimensions of some elements in the drawings may be exaggerated relative to other elements to help improve understanding of the examples discussed in this disclosure. The same reference numerals in different figures represent the same elements.

[0014] The term "or" refers to any one or more items in a list connected by "or". As an example, "x or y" refers to any element of the three-element set {(x), (y), (x, y)}. As another example, "x, y, or z" refers to any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}.

[0015] The terms “comprises,” “comprising,” “includes,” and / or “including” are “open” terms and specify the presence of stated features but do not preclude the presence or addition of one or more other features.

[0016] The terms "first," "second," etc., may be used herein to describe various elements, and these elements should not be limited by these terms. These terms are intended only to distinguish one component from another. Thus, for example, a first element discussed in this disclosure could be referred to as a second element without departing from the teachings of this disclosure.

[0017] Unless otherwise specified, the term "coupled" may be used to describe two elements that are in direct contact with each other or to describe two elements that are indirectly connected through one or more other elements. For example, if element A is coupled to element B, element A may be directly in contact with element B or indirectly connected to element B through an intermediate element C. Similarly, the terms "over" or "on" may be used to describe two elements that are in direct contact with each other or to describe two elements that are indirectly connected through one or more other elements.

[0018] Embodiments of the present disclosure may include an optical processing system comprising a beam displacer operable to receive an input light beam and split the input light beam into a first light beam and a second light beam having linear polarizations. Embodiments may also include a liquid crystal (LC) cell comprising a first position and a second position, operable to receive the first light beam at the first position and the second light beam at the second position.

[0019] According to various embodiments, the liquid crystal cell is operable to rotate the first light beam into a first LC output beam or the second light beam into a second LC output beam. According to various embodiments, the first LC output beam and the second LC output beam may have the same polarization after passing through the liquid crystal cell. Embodiments may also include a crystal wedge operable to receive the first LC output beam and the second LC output beam and direct both in a spatial output direction based on the same polarization of the first LC output beam and the second LC output beam.

[0020] According to various embodiments, the beam displacer can include a birefringent crystal. According to various embodiments, the birefringent crystal can be calcite or yttrium orthovanadate crystal. According to various embodiments, the input beam can include a portion of light linearly polarized in a first direction and a second portion of light linearly polarized in a second direction, where the second direction can be orthogonal to the first direction.

[0021] According to various embodiments, the first light beam and the second light beam may be differently polarized. According to various embodiments, the first light beam and the second light beam may be orthogonally polarized to each other. According to various embodiments, the liquid crystal cell may include one pixel at the first position and one pixel at the second position, respectively.

[0022] According to various embodiments, each of the pixels may be independently controlled. Implementations may also include each of the pixels being operable to rotate the input light beam based on independent control.

[0023] According to various embodiments, the liquid crystal cell can include a first position and a second position in a single pixel, such as V1. According to various embodiments, the first position can be controlled independently of the second position. According to various embodiments, the liquid crystal cell can include an array of such single pixels, operable to support a variety of optical processing systems and methods. According to various embodiments, each of the single pixels can include a first position and a second position. According to various embodiments, multiple first positions can be controlled together and multiple second positions can be controlled together by interlaced pattern electrodes.

[0024] According to various embodiments, collective control can be achieved by using a staggered pattern on the bottom electrode across a single pixel. According to various embodiments, the spatial output direction can be operated to couple the first LC output beam and the second LC output beam to the first optical output port or the second optical output port based on the same polarization of the first LC output beam and the second LC output beam.

[0025] Embodiments of the present disclosure may also include an optical processing method comprising splitting a received input light beam into a first light beam and a second light beam, at least a portion of the input light beam having a linear polarization. Embodiments may also include receiving the first light beam at a first location and receiving the second light beam at a second location.

[0026] Embodiments may further include rotating the first light beam into a first LC output beam or rotating the second light beam into a second LC output beam. According to various embodiments, the first LC output beam and the second LC output beam may have the same polarization. Embodiments may further include directing the first LC output beam and the second LC output beam in a spatial output direction based on the same polarization of the first LC output beam and the second LC output beam.

[0027] According to various embodiments, the method may include splitting an input light beam in a birefringent crystal acting as a beam displacer. According to various embodiments, the birefringent crystal may be calcite or yttrium orthovanadate crystal. According to various embodiments, the input light beam may include a portion of light linearly polarized in a first direction and a second portion of light linearly polarized in a second direction, the second direction being orthogonal to the first direction.

[0028] According to various embodiments, the first light beam and the second light beam may be polarized differently. According to various embodiments, the first light beam and the second light beam may be polarized orthogonally to each other. According to various embodiments, the rotation of the first light beam or the second light beam may be implemented in a liquid crystal cell, the liquid crystal cell including one pixel in the first position and one pixel in the second position, respectively.

[0029] Embodiments may also include pixels that are independently controllable. Embodiments may also include pixels that are individually operable to rotate an input light beam based on independent control.

[0030] According to various embodiments, the first location and the second location may be located on a single pixel of the liquid crystal cell. According to various embodiments, the method may include controlling the first location independently of the second location. According to various embodiments, the liquid crystal cell may include an array of single pixels operable to support multiple optical processing methods.

[0031] Embodiments may also include a single pixel, each of which may include a first position and a second position, including collectively controlling a plurality of first positions and a plurality of second positions. According to various embodiments, collective control may be achieved by using a staggered pattern on a bottom electrode across a single pixel. According to various embodiments, the method may include coupling the first LC output beam and the second LC output beam to the first optical output port or the second optical output port based on the first LC output beam and the second LC output beam having the same polarization.

[0032] Now refer to Figure 1 , Figure 1 is a block diagram illustrating an optical processing system 100 according to some embodiments of the present disclosure. In some embodiments, the optical processing system 100 can include a liquid crystal cell 120. The optical processing system 100 can also include a beam displacer 110 operable to receive an input light beam and split the input light beam into a first light beam and a second light beam based on linear orthogonal polarizations. The optical processing system 100 can also include a crystal wedge 130 operable to receive the first and second LC output light beams and direct them in a spatial output direction based on the same polarization of the first and second LC output light beams.

[0033] In some embodiments, the liquid crystal cell 120 may include a first location 122 operable to receive a first light beam. The liquid crystal cell 120 may also include a second location 124 operable to receive a second light beam. The liquid crystal cell 120 may be operable to rotate the first light beam into a first LC output light beam or to rotate the second light beam into a second LC output light beam. The first LC output light beam and the second LC output light beam may have the same polarization after passing through the liquid crystal cell 120.

[0034] In some embodiments, the beam displacer 110 may include a birefringent crystal. In some embodiments, the birefringent crystal may be calcite or yttrium orthovanadate crystal. In some embodiments, the input beam may further include a portion of light linearly polarized in a first direction and a second portion of light linearly polarized in a second direction, the second direction being orthogonal to the first direction.

[0035] In some embodiments, the first and second light beams can be polarized differently. In some embodiments, the first and second light beams can be polarized orthogonally to each other. In some embodiments, the liquid crystal cell 120 can include a pixel at each of the first position 122 and the second position 124. In some embodiments, each of the pixels can be independently controlled. In some embodiments, each of the pixels can be operable to rotate the input light beam based on independent control.

[0036] In some embodiments, the first position 122 can be controlled independently of the second position 124. In some embodiments, the spatial output direction can be operable to couple the first LC output beam and the second LC output beam to the first optical output port or the second optical output port based on the same polarization of the first LC output beam and the second LC output beam.

[0037] Figure 2A It further illustrates some embodiments of the present disclosure. Figure 1 The same reference numerals as in previous figures indicate similar or substantially identical elements.

[0038] The beam displacer 110 can receive an input beam 140. The polarization of the input beam 140 can include a linearly polarized signal light portion perpendicular to the plane of the drawing (indicated by an encircled "x," referred to as "X polarization") and a linearly polarized signal light portion parallel to the plane of the drawing (indicated by an arrow pointing toward the top of the page, referred to as "arrow polarization"). The X polarization can be represented by reference numerals 235, 210, 245, 220, 215, 225, and 230. The arrow polarization can be represented by reference numerals 240, 205, and 250.

[0039] Beam displacer 110 is operable to split signals having different polarizations included in input beam 140 into first beam 150 and second beam 160. First beam 150 may include a portion of input beam 140 that may have an arrow polarization. Second beam 160 may include a portion of input beam 140 that may have an X polarization. Accordingly, the polarization of first beam 150 may differ from the polarization of second beam 160, as shown by polarizations 205 and 210, e.g., linear and orthogonal.

[0040] A first light beam 150 can be coupled from the beam displacer 110 to a first position 122 on the liquid crystal cell 120. Similarly, a second light beam 160 can be coupled from the beam displacer 110 to a second position 124 on the liquid crystal cell 120. The liquid crystal cell 120 is operable to provide a plurality of controllable positions. For example, the first position 122, indicated by the vertical hashing, can indicate that the liquid crystal is exposed to a low control voltage. The low control voltage applied to the first position 122 can cause the input signal beam to rotate to the first position 122 as it passes through the liquid crystal cell 120. Accordingly, as indicated by the arrow polarization 250 when the first light beam 150 enters the first position 122, the first LC output light beam 170 from the position 122 has been rotated from the arrow polarization 250 to the X polarization 215.

[0041] Similarly, the second position 124, shown by the horizontal hashing, can indicate that the liquid crystal is exposed to a high control voltage. The high control voltage applied to the second position 124 can allow the input signal to the first position 122 to pass through without being rotated when passing through the liquid crystal cell 120. Accordingly, as shown by the X polarization 245 of the second light beam 160 when it enters the second position 124, the second LC output light beam 180 from the position 124 has not yet been rotated to the X polarization 245, 220.

[0042] According to various embodiments, LC cell 120 can include pixels in first position 122 and / or second position 124. Alternatively, LC cell 120 can include a single pixel including first position 122 and second position 124 that can be independently controlled. Accordingly, any number of positions can exist on a single pixel. According to some embodiments, any number of pixels can also exist.

[0043] The first position 122 and the second position 124 can be controlled with a low voltage and a high voltage, respectively, to cause the input light beam to rotate or not rotate, respectively.

[0044] like Figure 2A As shown, the first LC output 170 and the second LC output 180 can be polarized in the same direction, as shown by X polarization 215, 220. The first LC output 170 and the second LC output 180 can be coupled to a crystal wedge 130. The crystal wedge 130 is operable to direct input light into a specific spatial direction according to its polarization direction. Figure 2A As shown, the first LC output 170 and the second LC output 180 may be directed toward Port- 1 due to their X polarizations 215 , 220 , 225 , 230 , as shown.

[0045] Figure 2B Further shows the exchange in different spatial output directions Figure 2A . Figure 2B Basically with Figure 2A Similarly. However, the first position 122 can be controlled by a high voltage as indicated by the horizontal hashing. Similarly, the second position 124 can be controlled by a low voltage as indicated by the vertical hashing. Accordingly, the LC cell 120 in the first position 122 does not rotate the input first light beam 150. The LC cell 120 in the second position 124 can rotate the input second light beam 160 to change its X polarization 245 to arrow polarization 294. In this example, both the first LC output 170 and the second LC output 180 can be arrow polarized. Because the polarization of the first LC output 170 and the second LC output 180 can be different Figure 2A , so the crystal wedge 130 can direct the LC output beam 170 and the LC output beam 182 toward port-2, that is, in different spatial output directions.

[0046] Figure 2C Exemplary arrays of LC cells / pixels according to various embodiments of the present disclosure are shown.

[0047] An array of four liquid crystal cells / pixels V1-V4 is shown on top electrode 510. Bottom electrode 520 is also shown. V1 may represent an exemplary LC cell 120, which includes a first location 122 and a second location 124, shown as dashed lines. According to various embodiments of the present disclosure, V1-V4 may represent a single pixel LC cell. The first location 122 and the second location 124 of the LC cell 120 can be independently controlled by applying different voltage levels to the first interlaced pattern electrode 500 and the second interlaced pattern electrode 505 on the bottom electrode 520. By applying different voltages at the first location 122 and the second location 124, the corresponding regions of the single pixel V1 of the LC cell 120 can be controlled separately, allowing for rotation (or non-rotation) of input light as it passes through the LC cell 120 and / or the pixel V1 at the first location 122 or the second location 124, respectively. The staggered pattern electrodes 500, 505 can be used to supply two different voltages to each LC cell / pixel, thereby generating two regions on each pixel V1-V4 similar to the first location 122 and the second location 124. Accordingly, each pixel V1-V4 can be enabled to rotate input light whose surface area is associated with the applied low voltage.

[0048] Figure 3 is a flow chart describing an optical processing method according to some embodiments of the present disclosure. In some embodiments, at 310, the optical processing method may include splitting the received input light beam 140 into a first light beam 150 and a second light beam 160 based on linear orthogonal polarizations of at least a portion of the input light beam 140. At 320, the optical processing method may include receiving the first light beam 150 in the first position 122 and receiving the second light beam 160 in the second position 124. At 330, the optical processing method may include rotating the first light beam 150 into a first LC output beam 170 or rotating the second light beam 160 into a second LC output beam 180. At 340, the optical processing method may include directing the first LC output beam 170 and the second LC output beam 180 in a spatial output direction based on the same polarization of the first LC output beams 215, 292 and the second LC output beams 220, 294. The first LC output beam 170 and the second LC output beam 180 may have the same polarization.

[0049] In some embodiments, the method can include splitting the input beam 140 in a birefringent crystal that acts as the beam displacer 110. In some embodiments, the birefringent crystal can be calcite or yttrium vanadate crystal. In some embodiments, the input beam 140 can include a portion of light linearly polarized in a first direction 205 and a second portion of light linearly polarized in a second direction 210 that is orthogonal to the first direction 205.

[0050] In some embodiments, the polarizations of the first light beam 150 and the second light beam 160 can be different, such as linearly orthogonal polarizations 250 and 245. In some embodiments, the first light beam 150 and the second light beam 160 can be polarized orthogonally to each other, such as X polarization and arrow polarization. In some embodiments, the rotation of the first light beam 150 or the second light beam 160 can be implemented in a liquid crystal cell 120, which includes a pixel at each of the first position 122 and the second position 124. In some embodiments, each of the pixels can be independently controlled.

[0051] In some embodiments, each of the pixels is operable to rotate the input light beam 150, 160 based on independent control. In some embodiments, the first position 122 and the second position 124 can be located on a single pixel of the liquid crystal cell 120, see also Figure 2C In some embodiments, the method can include controlling the first position 122 independently of the second position 124. In some embodiments, the liquid crystal cell 120 can include an array of single pixels V1-V4 operable to support multiple optical processing methods.

[0052] In some embodiments, each of the individual pixels V1-V4 can include a first location 122 and a second location 124, including collectively controlling a plurality of first locations 122 and a plurality of second locations 124. In some embodiments, collective control can be achieved by using a staggered pattern 500, 505 on a bottom electrode 520 across the individual pixels V1-V4. In some embodiments, the method can include coupling the first LC output beam 170 and the second LC output beam 180 to a first optical output port (Port-1) or a second optical output port (Port-2) based on the first LC output beam 170 and the second LC output beam 180 having the same polarization (e.g., 292, 294).

[0053] The present disclosure includes reference to certain examples, however, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present disclosure. In addition, the disclosed embodiments may be modified without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the disclosed embodiments, but rather the present disclosure will include all examples that fall within the scope of the appended claims.

Claims

1. An optical processing system, comprising: a beam displacer operable to receive an input beam and split the input beam into a first beam and a second beam having orthogonal linear polarizations; A liquid crystal cell comprising a first position and a second position, the liquid crystal cell being operable to: receiving the first light beam at the first position and receiving the second light beam at the second position; and rotating the first light beam into a first LC output light beam or rotating the second light beam into a second LC output light beam, wherein the first LC output light beam and the second LC output light beam have the same polarization after passing through the liquid crystal cell; and A crystal wedge is operable to receive the first LC output beam and the second LC output beam and direct both in a spatial output direction based on the same polarization of the first LC output beam and the second LC output beam.

2. The system according to claim 1, wherein: The beam displacer includes a birefringent crystal.

3. The system according to claim 2, wherein: The birefringent crystal is calcite or yttrium orthovanadate crystal.

4. The system according to claim 1, wherein: The input light beam includes a portion of light linearly polarized in a first direction and a second portion of light linearly polarized in a second direction, the second direction being orthogonal to the first direction.

5. The system according to claim 1, wherein The first light beam and the second light beam are differently polarized.

6. The system according to claim 1, wherein: The first light beam and the second light beam are orthogonally polarized to each other.

7. The system according to claim 1, wherein: The liquid crystal cell includes one pixel in each of the first position and the second position.

8. The system according to claim 7, wherein: Each of the pixels can be controlled independently.

9. The system according to claim 8, wherein: Each of the pixels is operable to rotate an input light beam based on the independent control.

10. The system according to claim 1, wherein: The liquid crystal cell includes the first position and the second position in a single pixel.

11. The system according to claim 10, wherein: The first position can be controlled independently of the second position.

12. The system according to claim 10, wherein: The liquid crystal cell comprises an array of the single pixels operable to support a plurality of the optical processing systems.

13. The system according to claim 12, wherein: Each of the single pixels includes a first position and a second position, and wherein a plurality of the first positions can be commonly controlled, and a plurality of the second positions can be commonly controlled.

14. The system according to claim 13, wherein: The common control is achieved by using a staggered pattern on the bottom electrode across the single pixel.

15. The system of claim 1, wherein: The spatial output direction is operable to couple both the first LC output beam and the second LC output beam to a first optical output port or a second optical output port based on the same polarization of the first LC output beam and the second LC output beam.

16. A method for optical processing, comprising: splitting a received input beam into a first beam and a second beam having orthogonal linear polarizations; receiving the first light beam at a first location and receiving the second light beam at a second location; rotating the first light beam into a first LC output light beam or rotating the second light beam into a second LC output light beam, wherein the first LC output light beam and the second LC output light beam have the same polarization; and Both the first LC output beam and the second LC output beam are directed in a spatial output direction based on the same polarization of the first LC output beam and the second LC output beam.

17. The method according to claim 16, comprising: The input beam is split in a birefringent crystal that acts as a beam displacer.

18. The method according to claim 17, wherein The birefringent crystal is calcite or yttrium orthovanadate crystal.

19. The method according to claim 16, wherein The input light beam includes a portion of light linearly polarized in a first direction and a second portion of light linearly polarized in a second direction, the second direction being orthogonal to the first direction.

20. The method according to claim 16, wherein The first light beam and the second light beam are differently polarized.

21. The method according to claim 16, wherein The first light beam and the second light beam are orthogonally polarized to each other.

22. The method according to claim 16, wherein The rotation of the first light beam or the second light beam is implemented in a liquid crystal cell, which includes one pixel in each of the first position and the second position.

23. The method according to claim 22, wherein Each of the pixels can be controlled independently.

24. The method according to claim 23, wherein Each of the pixels is operable to rotate an input light beam based on the independent control.

25. The method according to claim 16, wherein The first position and the second position are located on a single pixel of the liquid crystal cell.

26. The method according to claim 25, comprising: The first position is controlled independently of the second position.

27. The method according to claim 25, wherein The liquid crystal cell includes an array of said single pixels operable to support a plurality of said optical processing methods.

28. The method according to claim 27, wherein Each of the single pixels includes a first position and a second position, and a plurality of the first positions and a plurality of the second positions are controlled together.

29. The method according to claim 28, wherein The common control is achieved by using a staggered pattern on the bottom electrode across the single pixel.

30. The method of claim 16, comprising: Based on the same polarization of the first LC output beam and the second LC output beam, both the first LC output beam and the second LC output beam are coupled to a first optical output port or a second optical output port.

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