Polarization-maintaining magneto-optical switch

Abstract

The utility model provides a polarization-maintaining magneto-optical switch which comprises a polarization-maintaining single-fiber collimator and a polarization splitting prism which are sequentially arranged along an optical path, a reflecting film is attached to the lower surface of the polarization splitting prism, and a light beam entering the polarization splitting prism is divided into a first light beam and a second light beam with the polarization directions perpendicular to each other. The second light beam is parallel to the first light beam after being reflected by the reflecting film; the first light beam is sequentially provided with a first Faraday rotator, a first polarization beam splitting walk-off prism, a second Faraday rotator, a second half-wave plate and a first polarization-maintaining double-fiber collimator along a light path; the second light beam is sequentially provided with a first half-wave plate, a first Faraday rotator, a second polarization splitting walk-off prism, a third half-wave plate and a second polarization-maintaining double-fiber collimator along the light path. According to the utility model, the polarization splitting prism is adopted to replace a birefringent crystal, so that the material cost is reduced, the difficulty of light spot separation is reduced by adopting a vertical light splitting mode, the light path is simplified, and the debugging difficulty is reduced.

Description

Technical Field

[0001] The utility model relates to the field of optical devices, in particular to a polarization-maintaining magneto-optical switch. Background Art

[0002] An optical switch (OS) is a device with one or more selectable transmission windows that can perform mutual conversion or logical operations on optical signals in an optical transmission line or integrated optical circuit. The basic form of an optical switch is 2X2, that is, there are two optical fibers at the input and output ends, which can achieve two connection states: parallel connection and cross connection. Figure 2 A larger space-division optical switching unit can be constructed by cascading and combining a basic 2x2 optical switch and a corresponding 1x2 optical switch.

[0003] A Chinese utility model patent, publication number CN210401904U, provides a 1×4 magneto-optical switch with a switching speed of tens of microseconds, significantly improving switching speed compared to mechanical optical switches. This utility model utilizes the magneto-optical effect, using a coil and Faraday crystal combination as the key components for optical path switching. Optical crystals of appropriate specifications (such as beam splitters and lenses) are then used to achieve the optical path switching function. However, this structure has the disadvantages of high cost, complex structure, poor stability, and weak shutdown capability. Utility Model Content

[0004] In order to solve the problems of the prior art, the utility model provides a polarization-maintaining magneto-optical switch, which adopts a polarization beam splitting prism instead of a birefringent crystal, thereby reducing material costs. At the same time, the vertical beam splitting method is adopted to reduce the difficulty of light spot separation, simplify the optical path, and reduce the difficulty of debugging.

[0005] The utility model comprises a polarization-maintaining single fiber collimator and a polarization beam splitter prism which are sequentially arranged along an optical path. A reflective film is attached to the lower surface of the polarization beam splitter prism. A light beam entering the polarization beam splitter prism is split into a first light beam and a second light beam whose polarization directions are perpendicular to each other. The second light beam is parallel to the first light beam after being reflected by the reflective film. A first Faraday rotator, a first polarization beam splitting walk-off prism, a second Faraday rotator, a second half-wave plate, and a first polarization-maintaining dual-fiber collimator are sequentially arranged along the optical path of the first light beam. A first half-wave plate, a first Faraday rotator, a second polarization beam splitting walk-off prism, a third half-wave plate, and a second polarization-maintaining dual-fiber collimator are sequentially arranged along the optical path of the second light beam.

[0006] As a further improvement, the first polarization splitting walk-off prism and the second polarization splitting walk-off prism respectively split the light beam into two beams of light with vertical polarizations and make the two beams of light walk away, and the directions of the first polarization splitting walk-off prism and the second polarization splitting walk-off prism are different.

[0007] The beneficial effects of the utility model are:

[0008] The use of polarization beam splitting prisms instead of birefringent crystals reduces material costs. At the same time, the use of vertical beam splitting reduces the difficulty of spot separation, simplifies the optical path, and reduces the difficulty of debugging.

[0009] The invention has the advantages of simple optical path structure, small size, no moving parts, good reliability and repeatability, simple debugging and assembly, and low material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 This is a schematic structural diagram of the utility model.

[0012] Figure 2 is the polarization state diagram of the first output light path.

[0013] Figure 3 is the polarization state diagram of the second output light path.

[0014] Figure 4 This is the polarization state diagram of the third output light path.

[0015] Figure 5 This is the polarization state diagram of the fourth output light path.

[0016] Figure 6 A schematic diagram of the comparative structure.

[0017] In the figure, 01-polarization-maintaining single fiber collimator; 02-polarization beam splitter prism; 03-first half-wave plate; 04-first Faraday rotator; 05-first polarization-splitting walk-off prism; 06-second polarization-splitting walk-off prism; 07-second Faraday rotator; 08-second half-wave plate; 09-third half-wave plate; 10-first polarization-maintaining dual fiber collimator; 11-second polarization-maintaining dual fiber collimator; 12-third Faraday rotator; 13-first half-wave plate; 14-first PBS; 15-fourth Faraday rotator; 16-second half-wave plate; 17-second PBS; 18-fifth Faraday rotator; 19-third half-wave plate; 20-third PBS. DETAILED DESCRIPTION

[0018] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] The utility model structure is as follows Figure 1 As shown, it includes a polarization-maintaining single fiber collimator 1 and a polarization beam splitter prism 2 arranged in sequence along the optical path. The lower surface of the polarization beam splitter prism is affixed with a reflective film. The light beam entering the polarization beam splitter prism is split into a first light beam and a second light beam with mutually perpendicular polarization directions. The second light beam is parallel to the first light beam after being reflected by the reflective film. The first light beam is sequentially provided with a first Faraday rotator 04, a first polarization beam splitting walk-off prism 05, a second Faraday rotator 07, a second half-wave plate 08, and a first polarization-maintaining dual-fiber collimator 10 along the optical path. The second light beam is sequentially provided with a first half-wave plate 03, a first Faraday rotator 04, a second polarization beam splitting walk-off prism 06, a third half-wave plate 09, and a second polarization-maintaining dual-fiber collimator 11 along the optical path.

[0020] As a further improvement, the first polarization splitting walk-off prism and the second polarization splitting walk-off prism respectively split the light beam into two beams of light with vertical polarizations and make the two beams of light walk away, and the directions of the first polarization splitting walk-off prism and the second polarization splitting walk-off prism are different.

[0021] The utility model can output four optical paths, and the polarization states of the optical paths are shown in the figure below. Figure 2-5 As shown, after the light beam passes through the polarization-maintaining single fiber collimator 01, it forms vertically polarized light, which is then split into two light beams by the polarization splitting prism 02. The first light beam does not pass through the first half-wave plate 03, and its polarization remains unchanged. The second light beam passes through the first half-wave plate 03, and its polarization changes. The two light beams then enter the first Faraday rotator 04 to control the Faraday rotator to change its polarization state. They are then split by the first polarization splitting walk-off prism 05 and the second polarization splitting walk-off prism 06, respectively, to form four light paths. The polarization state is then changed by the second Faraday rotator 07 and the second Faraday rotator, ultimately obtaining four outputs with different polarization states.

[0022] The utility model contrast structure is as follows Figure 6As shown, the optical system includes a third Faraday rotator 12, a first half-wave plate 13, and a first PBS 14, which are sequentially arranged along the optical path. The light beam is split into a first light beam and a second light beam with mutually perpendicular polarization directions by the first PBS 14. A fourth Faraday rotator 15, a second half-wave plate 16, and a second PBS 17 are sequentially arranged along the optical path of the first light beam. The second PBS splits the first light beam into two output light beams with mutually perpendicular polarization directions. A fifth Faraday rotator 18, a third half-wave plate 19, and a third PBS 20 are sequentially arranged along the optical path of the second light beam. The third PBS 20 splits the second light beam into two output light beams with mutually perpendicular polarization directions. By adjusting the orientation of the second PBS 17 and the third PBS 20, different light output positions can be obtained.

[0023] In actual engineering, this comparative structure is relatively more expensive than the technical solution protected by the present utility model. In addition, there are also stability issues in magnetic field control. The three Faraday rotators place high demands on the design of the magnetic field drive module.

[0024] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred implementation method of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with this technical field is within the technical scope disclosed by this utility model. For ordinary technicians in this technical field, changes or replacements that can be easily thought of should be included in the protection scope of this utility model without departing from the principle of this utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims

1. A polarization-maintaining magneto-optical switch, characterized in that: The invention comprises a polarization-maintaining single fiber collimator and a polarization beam splitter prism arranged in sequence along an optical path. A reflective film is attached to the lower surface of the polarization beam splitter prism. A light beam entering the polarization beam splitter prism is split into a first light beam and a second light beam with polarization directions perpendicular to each other. The second light beam is parallel to the first light beam after being reflected by the reflective film. A first Faraday rotator, a first polarization beam splitting walk-off prism, a second Faraday rotator, a second half-wave plate, and a first polarization-maintaining dual-fiber collimator are arranged in sequence along the optical path of the first light beam. A first half-wave plate, a first Faraday rotator, a second polarization beam splitting walk-off prism, a third half-wave plate, and a second polarization-maintaining dual-fiber collimator are arranged in sequence along the optical path of the second light beam.

2. The polarization-maintaining magneto-optical switch according to claim 1, wherein: The first polarization splitting walk-off prism and the second polarization splitting walk-off prism respectively split the light beam into two beams of light with vertical polarizations and make the two beams of light walk away. The directions of the first polarization splitting walk-off prism and the second polarization splitting walk-off prism are different.

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