Optical circulator and optical circulator core

Abstract

The utility model provides a kind of optical circulator and optical circulator core, and the optical circulator includes three ports, and the core is arranged between two ports;The core has first half wave plate, first rotating sheet, birefringent crystal, second rotating sheet and second half wave plate arranged in order along optical path, and first half wave plate, first rotating sheet, birefringent crystal, second rotating sheet and second half wave plate are glued together;The core is integrally cut into shape, and the cross section of first half wave plate, first rotating sheet, birefringent crystal, second rotating sheet and second half wave plate is equal along optical path direction;And, the thickness of first half wave plate is less than the thickness of first rotating sheet, and the thickness of second half wave plate is less than the thickness of second rotating sheet.The utility model further provides the core used by the above-mentioned optical circulator.The production process of the utility model's optical circulator is simple, and production cost is lower.

Description

Technical Field

[0001] This utility model relates to the technical field of optical devices, specifically to an optical circulator and the core of such an optical circulator. Background Technology

[0002] An optical circulator is a common optical device. Existing optical circulators have multiple ports and contain multiple components. After passing through the internal components, the light beam can only propagate along a specific optical path. Taking a transmission-type circulator as an example, the optical circulator contains a first half-wave plate, a first Faraday rotator, a birefringent crystal, a second Faraday rotator, and a second half-wave plate.

[0003] Because optical circulators are small in size, the components inside them are also very small. Therefore, manufacturing an optical circulator requires cutting and processing a large piece of optical component to the required size before assembly. For example, a large half-wave plate is cut into smaller half-wave plates. As optical circulators become smaller, the size of the internal optical components continues to decrease, increasing the difficulty of component cutting and assembly, and consequently raising production costs. In particular, the half-wave plate is the thinnest part of the optical circulator, making the assembly of smaller half-wave plates even more difficult, further increasing the production cost of the optical circulator. Summary of the Invention

[0004] The primary objective of this invention is to provide a light circulator that is easy to manufacture and can reduce production costs.

[0005] The second objective of this invention is to provide an optical circulator core that is easier to assemble.

[0006] To achieve the first objective of this utility model, the optical circulator provided by this utility model includes at least three ports, with a core disposed between two ports; the core has a first half-wave plate, a first rotating plate, a birefringent crystal, a second rotating plate, and a second half-wave plate arranged sequentially along the optical path, the first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate glued together; the core is integrally cut and shaped, and along the optical path direction, the cross-sections of the first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate are all equal; furthermore, the thickness of the first half-wave plate is less than the thickness of the first rotating plate, and the thickness of the second half-wave plate is less than the thickness of the second rotating plate.

[0007] As can be seen from the above scheme, the core is integrally cut and shaped. That is, during the production of the optical circulator core, the large-sized optical components are first fixed into a single unit using a gluing process before being cut into the required size core. This reduces the manufacturing difficulty of the optical circulator, thereby lowering its production cost and improving production efficiency. Furthermore, because the optical circulator core is produced by integral gluing followed by cutting, this invention allows for flexible expansion of the circulator channel. Components can be cut according to the required size of the light-transmitting surface. Using the same materials, only the process parameters need to be modified to suit different application scenarios, further reducing the production cost of the optical circulator.

[0008] A preferred embodiment is that the surfaces of the birefringent crystal near the first rotating plate and the surfaces near the second rotating plate are both light-transmitting surfaces; the optical axis of the birefringent crystal is not parallel to the light-transmitting surfaces, and the optical axis of the birefringent crystal is parallel to one of the non-light-transmitting surfaces of the birefringent crystal.

[0009] It can be seen that by properly setting the optical axis of the birefringent crystal, the beam can be split into normal light and abnormal light when passing through the core, and the polarization state can be rotated by combining the rotating plate, thereby realizing the control of the optical path.

[0010] A further approach is to have the thickness of the birefringent crystal greater than the thickness of the first rotating plate, and the thickness of the birefringent crystal greater than the thickness of the second rotating plate, along the optical path.

[0011] Because of the relatively large thickness of birefringent crystals, sufficient space is provided for the lateral shift of normal and abnormal light.

[0012] A further option is that the optical axis of the first half-wave plate is the same as that of the second half-wave plate; or the optical axis of the first half-wave plate is different from that of the second half-wave plate.

[0013] Therefore, the optical axes of the first and second half-wave plates can be configured reasonably according to actual usage needs to meet the usage requirements of different scenarios.

[0014] A further embodiment is that the first rotating plate is a first Faraday rotating plate; and / or the second rotating plate is a second Faraday rotating plate. Even further, the first Faraday rotating plate has an optical rotation angle of 45° under a saturated magnetic field; and / or the second Faraday rotating plate has an optical rotation angle of 45° under a saturated magnetic field.

[0015] It can be seen that by setting two Faraday rotators, the polarization state of the beam can be rotated appropriately, thereby meeting the optical path requirements of the optical circulator.

[0016] A further option is that an antireflection film is coated on the first light-transmitting surface of the first half-wave plate away from the first rotating plate; and / or an antireflection film is coated on the second light-transmitting surface of the second half-wave plate away from the second rotating plate.

[0017] Therefore, it can be seen that by setting an anti-reflection coating, the transmittance of the light beam can be improved, thereby reducing the insertion loss of the optical circulator.

[0018] A further proposed solution is to use a transmissive optical circulator with multiple ports distributed on both sides of the optical path of the core.

[0019] To achieve the second objective mentioned above, the optical circulator core provided by this utility model includes a first half-wave plate, a first rotating plate, a birefringent crystal, a second rotating plate, and a second half-wave plate arranged sequentially along the optical path. The first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate are bonded together, and the core is integrally cut and shaped. Along the optical path direction, the cross-sections of the first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate are all equal. Furthermore, the thickness of the first half-wave plate is less than the thickness of the first rotating plate, and the thickness of the second half-wave plate is less than the thickness of the second rotating plate.

[0020] As can be seen from the above scheme, since the core of the optical circulator is cut into shape as a whole, when making the core of the optical circulator, the large-sized optical components are first fixed into a whole by gluing before cutting, and then cut into the core of the required size. This reduces the difficulty of the optical circulator manufacturing process, thereby reducing the production cost of the optical circulator and improving production efficiency.

[0021] A preferred embodiment is that the surfaces of the birefringent crystal near the first rotating plate and the surface near the second rotating plate are both light-transmitting surfaces; the optical axis of the birefringent crystal is not parallel to the light-transmitting surfaces, and the optical axis of the birefringent crystal is parallel to one of the non-light-transmitting surfaces of the birefringent crystal. Attached Figure Description

[0022] Figure 1 This is a structural diagram of an embodiment of the optical circulator core of this utility model.

[0023] Figure 2 This is a perspective view of an embodiment of the optical circulator core of this utility model.

[0024] Figure 3 This is a structural diagram of the material used to manufacture the optical circulator core of this utility model.

[0025] Figure 4 This is a structural diagram of the optical circulator core embodiment of this utility model before cutting.

[0026] Figure 5 This is a structural diagram of the first half-wave plate original sheet used in the embodiment of the optical circulator core of this utility model.

[0027] Figure 6 This is a structural diagram of the birefringent crystal substrate and its cut structure in an embodiment of the optical circulator core of this utility model.

[0028] Figure 7 This is a structural diagram of the cut-out structure of the optical circulator core embodiment of this utility model.

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0030] The optical circulator of this invention has three or more ports and is equipped with a core. Preferably, the optical circulator of this invention is a transmissive optical circulator, with multiple ports respectively located on both sides of the core.

[0031] See Figure 1 and Figure 2 The core of the optical circulator comprises a first half-wave plate 11, a first rotating plate 12, a birefringent crystal 13, a second rotating plate 14, and a second half-wave plate 15 arranged sequentially along the optical path. Furthermore, the first half-wave plate 11, the first rotating plate 12, the birefringent crystal 13, the second rotating plate 14, and the second half-wave plate 15 are integrally bonded together; that is, the core is integrally cut and shaped. Figure 1 As can be seen, along the optical path, the cross-sections of the first half-wave plate 11, the first rotating plate 12, the birefringent crystal 13, the second rotating plate 14, and the second half-wave plate 15 are all equal.

[0032] The side of the first half-wave plate 11 away from the first rotating plate 12 is a light-transmitting surface, coated with an anti-reflection film. Similarly, the side of the second half-wave plate 15 away from the second rotating plate 14 is also a light-transmitting surface, coated with an anti-reflection film. Furthermore, the first rotating plate 12 is a first Faraday rotating plate, and the second rotating plate 14 is a second Faraday rotating plate. The optical rotation angle of the first Faraday rotating plate under a saturated magnetic field is 45°, and the optical rotation angle of the second Faraday rotating plate under a saturated magnetic field is also 45°.

[0033] The thicknesses of the five optical elements in the core are not exactly equal. Specifically, the first half-wave plate 11 and the second half-wave plate 15 have the smallest thicknesses, while the birefringent crystal 13 has the largest thickness. Furthermore, the thickness of the first half-wave plate 11 is less than the thickness of the first rotating plate 12, the thickness of the second half-wave plate 15 is less than the thickness of the second rotating plate 14, and the thickness of the birefringent crystal 13 is greater than both the thickness of the first rotating plate 12 and the second rotating plate 14.

[0034] To meet the optical path requirements of the optical circulator, the optical axes of each optical element have specific requirements. Specifically, the surface of the birefringent crystal 13 closest to the first rotating plate 12 is a light-transmitting surface, and the surface of the birefringent crystal 13 closest to the second rotating plate 14 is another light-transmitting surface; that is, the two light-transmitting surfaces of the birefringent crystal 13 are parallel to each other. The optical axis of the birefringent crystal 13 is not parallel to either of its light-transmitting surfaces, and the optical axis of the birefringent crystal is parallel to one of its non-light-transmitting surfaces. Figure 2 As shown in the figure, the dashed line in the birefringent crystal 13 is the optical axis of the birefringent crystal 13, and the angle between it and the light-transmitting surface is 45°. In addition, the optical axes of the first half-wave plate 11 and the second half-wave plate 15 can be equal or unequal, which can be set according to actual needs.

[0035] The following describes the manufacturing process of the instrument's core. (See also...) Figure 3 First, large optical components need to be prepared by cutting the raw materials to the specified dimensions. For example, the Faraday rotator raw material is cut into large pieces of first Faraday rotator original 22 and second Faraday rotator original 24. Furthermore, according to the optical axis requirements of the first half-wave plate 11 and the second half-wave plate 15 in the finished core, the large half-wave plate raw material is cut into first half-wave plate original 21 and second half-wave plate original 25. Since the optical axes of both the first half-wave plate 11 and the second half-wave plate 15 are 22.5° in this embodiment, the optical axes of the cut first half-wave plate original 21 and second half-wave plate original 25 are also 22.5°. Figure 5 As shown. In addition, before cutting the raw material of the half-wave plate, it is necessary to determine the cutting reference and ensure that the size of the light-transmitting surface of the first half-wave plate 21 and the second half-wave plate 25 is the same as that of the first Faraday rotation plate 22 and the second Faraday rotation plate 24.

[0036] Next, based on the optical axis direction and crystal length requirements of the birefringent crystal 13 in the finished core, such as... Figure 6 As shown, after determining the cutting reference, the birefringent crystal raw material 31 is cut to obtain the birefringent crystal substrate 23, and it is necessary to ensure that the size of the light-transmitting surface of the birefringent crystal substrate 23 is the same as the size of the light-transmitting surface of the first Faraday rotatable substrate 22. In addition, the two light-transmitting surfaces of the birefringent crystal substrate 23 need to be ground and polished to make them ideal surfaces.

[0037] Then, according to the optical axis orientation requirements of each optical element in the finished product, the original films are arranged in the specified direction and order, such as... Figure 3 As shown, the first half-wave plate 21, the first Faraday rotatable plate 22, the birefringent crystal 23, the second Faraday rotatable plate 24, and the second half-wave plate 25 are arranged in sequence, and it is necessary to ensure that the optical axis of each plate is consistent with the optical axis of each optical element in the finished core.

[0038] Next, the first half-wave plate 21, the first Faraday rotatable plate 22, the birefringent crystal 23, the second Faraday rotatable plate 24, and the second half-wave plate 25 are glued together and fixed into a single unit, as shown below. Figure 4 As shown. Then, the light-transmitting surfaces on both sides of the glued component are coated, that is, anti-reflection coatings are deposited on the two light-transmitting surfaces on the outer sides of the first half-wave plate 21 and the second half-wave plate 25.

[0039] Finally, based on the required light transmission surface size of the finished core, and using the optical axis of the first half-wave plate 11 or the birefringent crystal 13 as a reference, the glued assembly is cut to obtain cores 10 for multiple optical circulators, such as... Figure 7 As shown.

[0040] As can be seen, the core 10 of the optical circulator of this utility model is integrally cut and formed. That is, when producing the core 10 of the optical circulator, the large-sized optical originals are first fixed into a whole by adhesive bonding, and then cut into the core 10 of the required size. This method can reduce the difficulty of the optical circulator production process, thereby reducing the production cost of the optical circulator and improving the production efficiency.

[0041] In addition, since the core 10 of the optical circulator is manufactured by integral bonding and then cutting, this utility model can realize flexible expansion of the circulator channel. The element is cut according to the required size of the light transmission surface. Using the same material, only the process parameters need to be modified to be applicable to different application scenarios, which further reduces the production cost of the optical circulator.

[0042] Finally, it should be emphasized that the above are only preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An optical circulator, comprising at least three ports, with a core disposed between the ports; Its features are: The core has a first half-wave plate, a first rotating plate, a birefringent crystal, a second rotating plate, and a second half-wave plate arranged sequentially along the optical path. The first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate are glued together. The core is integrally cut and shaped, and the cross-sections of the first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate are all equal along the optical path. Furthermore, the thickness of the first half-wave plate is less than the thickness of the first rotating plate, and the thickness of the second half-wave plate is less than the thickness of the second rotating plate.

2. The optical circulator according to claim 1, characterized in that: The surfaces of the birefringent crystal near the first rotating plate and the surfaces near the second rotating plate are both light-transmitting surfaces; The optical axis of the birefringent crystal is not parallel to the light-transmitting surface, and the optical axis of the birefringent crystal is parallel to one of the non-light-transmitting surfaces of the birefringent crystal.

3. The optical circulator according to claim 2, characterized in that: Along the optical path, the thickness of the birefringent crystal is greater than the thickness of the first rotating plate, and the thickness of the birefringent crystal is greater than the thickness of the second rotating plate.

4. The optical circulator according to any one of claims 1 to 3, characterized in that: The optical axis of the first half-wave plate is the same as that of the second half-wave plate; or The optical axis direction of the first half-wave plate is different from that of the second half-wave plate.

5. The optical circulator according to any one of claims 1 to 3, characterized in that: The first rotator is a first Faraday rotator; and / or The second rotating plate is a second Faraday rotating plate.

6. The optical circulator according to claim 5, characterized in that: The optical rotation angle of the first Faraday rotator under a saturated magnetic field is 45°; and / or The optical rotation angle of the second Faraday rotator plate under a saturated magnetic field is 45°.

7. The optical circulator according to any one of claims 1 to 3, characterized in that: The first half-wave plate has an anti-reflection coating on its first light-transmitting surface away from the first rotating plate; and / or An anti-reflection coating is deposited on the second light-transmitting surface of the second half-wave plate, which is away from the second rotating plate.

8. The optical circulator according to any one of claims 1 to 3, characterized in that: The optical circulator is a transmissive optical circulator, and the multiple ports are distributed on both sides of the optical path direction of the core.

9. An optical circulator core, characterized by include: A first half-wave plate, a first rotating plate, a birefringent crystal, a second rotating plate, and a second half-wave plate are arranged sequentially along the optical path. The first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate are glued together. The core is integrally cut and shaped. Along the optical path direction, the cross-sections of the first half-wave plate, the first rotating plate, the birefringent crystal, the second rotating plate, and the second half-wave plate are all equal. Furthermore, the thickness of the first half-wave plate is less than the thickness of the first rotating plate, and the thickness of the second half-wave plate is less than the thickness of the second rotating plate.

10. The optical circulator core according to claim 9, characterized in that: The surfaces of the birefringent crystal near the first rotating plate and the surfaces near the second rotating plate are both light-transmitting surfaces; The optical axis of the birefringent crystal is not parallel to the light-transmitting surface, and the optical axis of the birefringent crystal is parallel to one of the non-light-transmitting surfaces of the birefringent crystal.

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