阅读说明：本技术 一种透镜保偏光纤 (Lens polarization maintaining optical fiber ) 是由 操质彬 谭策 吴正超 张心贲 李小兵 于 2020-06-08 设计创作，主要内容包括：本发明公开了一种透镜保偏光纤,所述透镜保偏光纤为熊猫型保偏光纤,其端面的顶部加工成半柱透镜,所述半柱透镜用于汇聚保偏光纤传导的偏振光,并耦合到保偏光纤耦合器接收端。本发明制得的透镜保偏光纤在保偏光纤的基础上进行微加工,作用区域小,无需附加其他部件,因此易于封装且体积小；楔面和微透镜结构对光斑进行整形匹配,因此光斑与光纤的耦合效率提高。其制作的保偏光纤耦合器,结构紧凑、体积小、使用寿命长,能被广泛用于航空、航天、航海、通信等各个领域的器件中,如光纤陀螺、水听器等的耦合器件,EDFA、Y波导等的尾纤。(The invention discloses a lens polarization maintaining fiber which is a panda type polarization maintaining fiber, wherein the top of the end surface of the lens polarization maintaining fiber is processed into a semi-cylindrical lens, and the semi-cylindrical lens is used for converging polarized light transmitted by the polarization maintaining fiber and is coupled to the receiving end of a polarization maintaining fiber coupler. The lens polarization maintaining optical fiber is micro-processed on the basis of the polarization maintaining optical fiber, the action area is small, and other components are not required to be added, so that the lens polarization maintaining optical fiber is easy to package and small in size; the wedge surface and the micro-lens structure are used for shaping and matching the light spots, so that the coupling efficiency of the light spots and the optical fiber is improved. The polarization-maintaining fiber coupler manufactured by the method has the advantages of compact structure, small volume and long service life, and can be widely applied to devices in various fields of aviation, aerospace, navigation, communication and the like, such as coupling devices of fiber optic gyroscopes, hydrophones and the like, and tail fibers of EDFA, Y waveguides and the like.)

1. The lens polarization maintaining fiber is characterized in that the lens polarization maintaining fiber is a panda type polarization maintaining fiber, the top of the end face of the lens polarization maintaining fiber is processed into a semi-cylindrical lens, and the semi-cylindrical lens is used for converging polarized light transmitted by the polarization maintaining fiber and is coupled to the receiving end of a polarization maintaining fiber coupler.

2. The lens polarization maintaining fiber of claim 1 having first and second wedge facets that are plane-symmetric about a central axis, said half-cylinder lens being machined into a curved surface where said first and second wedge facets intersect.

3. The lens polarization maintaining fiber of claim 2, wherein the first and second wedge surfaces are angled between 15 ° and 60 ° from the central axial plane.

4. The lens-polarizing fiber of claim 2, wherein the side of the first and second wedge-facets that intersect in extension is angled between 78 ° and 86 °, preferably 82 °, with the fiber axis.

5. The lensed polarization maintaining fiber of claim 2, wherein the side of the first and second wedge surfaces intersecting in extension is at an angle of 0 ° or 90 °, preferably 90 °, to a line connecting the centers of the panda's eyes.

6. The lens polarization maintaining fiber of any one of claims 2 to 5, wherein the radius of curvature of the semicylindrical lens is between 3 and 12 μm, preferably between 4 and 7 μm.

7. The lens-polarizing fiber of claim 1, having a third wedge surface perpendicular to the central axial plane at an angle of between 20 ° and 40 °, preferably 30 °, to the fiber axis.

Technical Field

The invention belongs to the field of electro-optic and silicon optical coupling, and particularly relates to a lens polarization-maintaining optical fiber.

Background

The polarization maintaining fiber is a special linear polarization single-mode fiber, is used as a tail fiber of communication devices such as EDFA, Y waveguide and other components in the field of optical communication, is widely used in various fields such as aviation, aerospace, navigation, communication and the like, can ensure that the linear polarization direction is unchanged, improves the coherent signal-to-noise ratio and realizes high-precision sensing measurement. High performance devices are increasingly used in the fields of optical communication and optical sensing, and devices such as EDFAs and Y waveguides need to improve the overall output power to improve the performance of optical amplification and waveguide output.

In order to improve the overall output power, a common mode is to couple an emergent light beam into a tail fiber after the emergent light beam is shaped by a micro lens or a micro lens group, and the coupling efficiency can reach 50% -80%.

Disclosure of Invention

The invention provides a lens polarization-maintaining optical fiber, aiming at solving the technical problems that the polarization-maintaining optical fiber, a lens and a receiver are required to be coupled in the existing polarization-maintaining optical fiber coupler, and the coupling difficulty is large, the efficiency is low, the structure is complex and the size is large due to the fact that the panda eye is aligned, and the coupling difficulty is high, the efficiency is low, the structure is complex and the size is large due to the fact that the end face of the panda eye type polarization-maintaining optical fiber is processed into the specific shape with the lens structure, so that transmission signal light can be transmitted in the optical fiber after being shaped and matched with light spots, the coupling efficiency is improved, the space requirement of a polarization optical coupler is reduced, and the packaging difficulty is reduced.

To achieve the above object, according to one aspect of the present invention, there is provided a lens polarization maintaining fiber, wherein the lens polarization maintaining fiber is a panda type polarization maintaining fiber, and the top of the end surface of the lens polarization maintaining fiber is processed into a semi-cylindrical lens, and the semi-cylindrical lens is used for converging polarized light transmitted by the polarization maintaining fiber and is coupled to the receiving end of a polarization maintaining fiber coupler.

Preferably, the lens polarization maintaining fiber has a first and a second wedge surfaces which are plane-symmetric about a central axis, and the semicylindrical lens is processed and formed on a curved surface where the first and the second wedge surfaces intersect.

Preferably, the first and second wedge surfaces of the lens polarization maintaining fiber are inclined at an angle of 15 ° to 60 ° with respect to the central axial plane.

Preferably, the edge of said lens polarization maintaining fiber where said first and second wedge-facets extend to intersect is at an angle of between 78 ° and 86 °, preferably 82 °, to the fiber axis.

Preferably, the included angle between the edge of the lens polarization maintaining fiber where the first and second wedge surfaces are extended and intersected and the line connecting the centers of the panda eyes is 0 ° or 90 °, and preferably 90 °.

Preferably, the curvature radius of the semi-cylindrical lens of the lens polarization-maintaining fiber is between 3 and 12 μm.

Preferably, the lens polarization maintaining fiber of the lens polarization maintaining fiber has a third wedge surface perpendicular to the central axial surface and forming an included angle of 20 ° to 40 ° with the fiber axis, and preferably 30 °.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

compared with the prior art, the lens polarization maintaining optical fiber is micro-processed on the basis of the polarization maintaining optical fiber, has small action area, does not need to be added with other components, and is easy to package and small in size; the wedge-shaped surface and the micro-lens structure are used for shaping and matching the light spot, so that the coupling efficiency of the light spot and the optical fiber is improved. The polarization-maintaining fiber coupler manufactured by the method has the advantages of compact structure, small volume and long service life, and can be widely applied to devices in various fields of aviation, aerospace, navigation, communication and the like, such as coupling devices of fiber optic gyroscopes, hydrophones and the like, and tail fibers of EDFA, Y waveguides and the like.

Drawings

FIG. 1 is a schematic diagram of a structure of a lens polarization maintaining fiber provided by the present invention;

FIG. 2 is a schematic diagram of a structure of a lens polarization maintaining fiber according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a structure of a lens polarization maintaining fiber according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a lens polarization maintaining fiber according to an embodiment of the present invention.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: the polarization maintaining optical fiber comprises a panda-type polarization maintaining optical fiber stress area 1, a first wedge-shaped surface 2, a second wedge-shaped surface 3, a semicylindrical lens 4 and a third wedge-shaped surface 5.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The invention provides a lens polarization maintaining fiber for manufacturing a polarization maintaining fiber coupler, which is a panda type polarization maintaining fiber as shown in figure 1, wherein the top of the end surface of the polarization maintaining fiber is processed into a semi-cylindrical lens; and the semi-cylindrical lens is used for converging the polarized light transmitted by the polarization-maintaining optical fiber and is coupled to the receiving end of the polarization-maintaining optical fiber coupler.

Preferably, the lens polarization maintaining fiber has a first and a second wedge-shaped surfaces that are symmetrical about a central axis plane, and the semicylindrical lens is processed and formed on a curved surface where the first and the second wedge-shaped surfaces intersect, as shown in fig. 2; preferably, the first and second wedge faces are at an angle of between 15 ° and 60 ° to the central axis plane; the included angle between the extension and intersection edge of the first wedge-shaped surface and the second wedge-shaped surface and the axis of the optical fiber is 78-86 degrees, so that the ratio of the fast axis to the slow axis is proper, and the maximum coupling efficiency with the light source is ensured; the included angle between the extending and intersecting edge of the first wedge-shaped surface and the connecting line of the circle centers of the panda eyes is 0 degree or 90 degrees, and the optimal 90 degrees ensure the processing efficiency and the qualification rate of the process at the same time; the curvature radius of the semi-cylindrical lens is preferably between 3 and 12 mu m, and preferably between 4 and 7 mu m. An included angle between the first wedge-shaped surface and the second wedge-shaped surface of the wedge-shaped end surface is 90 degrees, so that the lens polarization-maintaining optical fiber has the maximum coupling tolerance with a light source; the existence of the first wedge-shaped surface and the second wedge-shaped surface effectively adjusts light spots, reduces the space requirement of the polarization maintaining optical fiber coupler, forms a proper coupling distance and improves the coupling tolerance.

Preferably, the lens polarization maintaining fiber has a third wedge surface perpendicular to the central axial surface and forming an included angle of 20 degrees to 40 degrees with the axis of the fiber, preferably 30 degrees, and the effect of reducing reflected light is most obvious. The third wedge-shaped surface can reduce the back coupling of the reflected light into the polarization-maintaining optical fiber, thereby improving the coupling efficiency, and more importantly, reducing the signal interference caused by the reflected light and prolonging the service life of the polarization-maintaining optical fiber.

When the lens polarization-maintaining optical fiber provided by the invention is used for preparing a polarization-maintaining optical fiber coupler, the requirement on space can be effectively reduced, and the volume of the polarization-maintaining optical fiber coupler is reduced; more importantly, due to the integrated design of the lens and the polarization maintaining fiber, a good light spot is formed during manufacturing, multiple coupling is not needed, and the alignment difficulty is greatly reduced; meanwhile, compared with the conical design, the coupling efficiency is obviously improved. The invention does not use the micro lens group, has higher coupling tolerance, ensures the convenience of packaging and reduces the manufacturing cost of the device.

The coupling mode of the lens polarization-maintaining fiber can overcome the defects of large coupling difficulty and large required space of the traditional micro lens and the micro lens group, however, the coupling efficiency is far away due to the shape design of the lens on the end face, and the coupling efficiency of the common end face processing is low and is only 20 to 30 percent. The design of the end face of the lens polarization-maintaining optical fiber is extremely important under the premise. Through repeated practice, the coupling efficiency of the semicylindrical lens and the conical lens in various types of microlenses is equivalent to that of the conventional microlens set, however, when the optical field is adjusted by matching with the wedge-shaped surface to improve the coupling tolerance, the coupling efficiency of the polarization-maintaining optical fiber of the conical lens is greatly reduced, the coupling efficiency can be effectively improved to 60-80% by matching the end face of the wedge-shaped polarization-maintaining optical fiber with the semicylindrical lens, and the coupling efficiency can be improved to 70-90% by matching the preferred scheme with the third wedge-shaped surface.

The following are examples: