WO2022041340A1

WO2022041340A1 - Low-cost small optical circulator

Info

Publication number: WO2022041340A1
Application number: PCT/CN2020/115583
Authority: WO
Inventors: 赵武丽; 李阳; 邓伟松; 林念念; 王宗源; 薛听雨; 徐云兵
Original assignee: 福州高意通讯有限公司
Priority date: 2020-08-24
Filing date: 2020-09-16
Publication date: 2022-03-03
Also published as: CN114089480A

Abstract

Disclosed is a low-cost small optical circulator, which is formed by gluing a left polarization beam splitter gluing prism, a half-wave plate, a magneto-optical rotation piece, and a right polarization beam splitter gluing prism having a high reflective film plated on one surface. The left polarization beam splitter gluing prism is formed by gluing a parallelogram prism and a right angle triangular prism. The right polarization beam splitter gluing prism is formed by gluing a parallelogram prism and a right angle triangular prism having a high reflective film plated on one surface. In cooperation with a single fiber collimator, a dual fiber collimator or an optical port assembly, the circulator core can be used for realizing a single-core or two-in-one low-cost small circulator, and the circulator has the advantages of high isolation degree, low cost, and small size.

Description

A low-cost small optical circulator

technical field

The invention relates to the field of optical communication devices, in particular to a low-cost small optical circulator.

Background technique

With the vigorous development of high-speed optical networks and data centers, optical communication equipment requires optical modules to have both small size and low cost. Optical circulators are widely used in optical modules because they have the function of transmitting optical signals in a specific direction, and can improve integration and reduce costs by sharing common terminals to send and receive optical signals.

In such an application scenario, the application requirements of communication equipment for circulators have undergone great changes compared with traditional online circulators, which are embodied in the following two aspects:

a) Intensified demand for low cost;

b) The high integration with optical modules brings diversification of packaging forms, such as direct integration with optical port components and two-in-one structure.

Therefore, it is of great market value and significance to study how to reduce the cost and provide a more compact optical circulator with better performance.

SUMMARY OF THE INVENTION

Aiming at the situation of the prior art, the purpose of the present invention is to provide a low-cost small optical circulator which is compact in structure, low in cost, and can meet the special application requirements of the existing high-speed optical network and data center for the circulator.

In order to realize the above-mentioned technical purpose, the technical scheme adopted in the present invention is:

A low-cost small optical circulator is characterized in that: it comprises a left polarization beam splitter, a magneto-optical rotating plate, a half-wave plate and a right polarization beam splitter arranged in sequence, and the upper end surface of the right polarization beam splitter is coated with With high reflective film.

As a possible implementation manner, the further described left polarization beam splitter, magneto-optical rotating plate, half-wave plate and right polarization beam splitter coated with a high-reflection film on one side constitute a circulator core.

As a possible implementation manner, further, the left polarization beam splitter, the magneto-optical rotating plate, the half-wave plate and the right polarization beam splitter are sequentially glued into one.

As a possible implementation manner, further, the left polarizing beam splitter is formed by gluing a parallel block and a right angle triangular prism, wherein the lower end surface of the parallel block of the left polarizing beam splitter is an inclined plane structure and is connected to the right angle triangular prism. The right-angle surfaces of the left polarizing beam splitter are attached to each other, and the end face of the parallel block of the left polarizing beam splitter close to the magneto-optical rotating plate is attached to the upper part of the magneto-optical rotating plate, and the upper part of the inclined surface of the right-angle prism of the left polarizing beam splitter is rotated with the magneto-optical rotating plate. The lower part of the sheet is attached; in addition, the right polarizing beam splitter is also formed by gluing a parallel block and a right angle triangular prism, and the upper end surface of the parallel block of the right polarizing beam splitter is an inclined plane structure and is opposite to the inclined plane of the right angle prism. Fitting, and the end face of the parallel block of the right polarizing beam splitter close to the half-wave plate is fitted with the lower part of the half-wave plate, and the right-angle surface of the right-angle triangular prism of the right polarizing beam splitter is fitted with the upper part of the half-wave plate, The other right-angle surface of the right-angle triangular prism of the right polarizing beam splitter is coated with a high-reflection film.

As a preferred implementation option, preferably, the rotation angle of the magneto-optical rotating plate is 45°; the design value of the optical axis of the half-wave plate is 22.5° or 67.5°.

As a preferred implementation option, preferably, the magneto-optical rotating plate cooperates with the half-wave plate to form a non-reciprocal optical path structure, which is used to rotate the polarization direction of the optical signal passing through one of the directions by 90°, The polarization direction of the optical signal passing in the other direction remains unchanged.

As a preferred implementation option, preferably, an optical signal port I is formed at the lower part of the inclined plane of the right-angle block of the left polarization beam splitter, and the parallel block of the left polarization beam splitter is far away from the end face of the magneto-optical rotating plate to form an optical signal Port II, the end face of the parallel block of the right polarization beam splitter away from the half-wave plate forms the optical signal port III.

When the circulator core is working, the light beam of the optical signal port I is incident from the hypotenuse side of the right angle triangular prism of the left polarization beam splitter, and the light beam of the optical signal port II is incident from the side of the parallel block of the left polarization beam splitter. The beam of port III exits from the parallel block side of the right polarizing beam splitter.

As one of the possible implementation structures, the optical circulator further includes three single-fiber collimators corresponding to the optical signal port I, the optical signal port II, and the optical signal port III one-to-one, that is, the circulator core and the Three single-fiber collimators together form a three-port circulator.

As the second possible implementation structure, the optical circulator further includes three dual-fiber collimators corresponding to the optical signal port I, the optical signal port II and the optical signal port III one-to-one, wherein the optical signal port I corresponding to the optical signal port I The dual-fiber collimator is cross-coupled with the dual-fiber collimator corresponding to the optical signal port II, and the dual-fiber collimator corresponding to the optical signal port II is also cross-coupled with the dual-fiber collimator corresponding to the optical signal port III, that is, the The circulator core and three dual-fiber collimators together form a three-port two-in-one circulator.

As a third possible implementation structure, the optical circulator further includes two single-fiber collimators and an optical port assembly; wherein the two single-fiber collimators correspond to the optical signal port I and the optical signal port III respectively and are used for It is used for the input and output coupling of the optical signal of the optical signal port I and the optical signal port III, and the optical port component corresponds to the optical signal port II and is used for the input and output coupling of the optical signal of the optical signal port II, that is, the circulator core, the two A single fiber collimator and an optical port assembly together form a three-port circulator with an integrated optical port assembly.

A small optical circulator is characterized in that: it comprises two low-cost small optical circulators described in the third implementation structure arranged in up and down mirror images; one of the low-cost small optical circulators has a left polarization beam splitter and its optical A turning parallel block is arranged between the port assemblies, that is, two circulator cores, four single-fiber collimators, a turning parallel block and two optical port assemblies together form a two-in-one three-port circulator.

Using the above technical solution, compared with the prior art, the present invention has the following beneficial effects: this solution utilizes a circulator core with a high-reflection film to cooperate with a dual-fiber collimator or a turning parallel block and an optical port assembly, The isolation and integration of the circulator are improved, and the unit price of each circulator is effectively reduced.

Description of drawings

The scheme of the present invention will be further elaborated below in conjunction with the accompanying drawings and specific embodiments:

Figure 1 is a structural block diagram of an optical transceiver module that integrates a three-port circulator and transmits and receives optical signals through a shared optical port;

FIG. 2 is a structural block diagram of a two-in-one optical transceiver module whose package structure includes two optical transceiver functional components;

3 is a schematic diagram of the optical path of the circulator core according to Embodiment 1 of the present invention;

4 is a schematic diagram of an optical path from an optical signal port I to an optical signal port II of the circulator core based on Embodiment 1;

5 is a schematic diagram of an optical path from an optical signal port II to an optical signal port III of the circulator core based on Embodiment 1;

6 is a schematic diagram of polarization state deflection of the half-wave plate shown in FIG. 4 to right 45° linearly polarized light;

7 is a schematic diagram of polarization state deflection of the half-wave plate shown in FIG. 4 to left 45° linearly polarized light;

FIG. 8 is a schematic diagram of the polarization state deflection of the vertical linearly polarized light by the half-wave plate shown in FIG. 4 (light from right to left);

9 is a schematic diagram of the polarization state deflection of the half-wave plate shown in FIG. 4 (light from right to left) to horizontal linearly polarized light;

10 is a top view of the optical path of the three-port circulator (based on a single-fiber collimator) according to Embodiment 2 of the present invention;

11 is a side view of an optical path of a three-port circulator (based on a single-fiber collimator) according to Embodiment 2 of the present invention;

12 is a top view of the optical path of the two-in-one three-port circulator (based on the dual-fiber collimator) according to Embodiment 3 of the present invention;

13 is a side view of the optical path of the two-in-one three-port circulator (based on the dual-fiber collimator) according to Embodiment 3 of the present invention;

14 is a schematic top view of a small three-port circulator (based on an optical port) according to Embodiment 4 of the present invention;

FIG. 15 is a schematic top view of a two-in-one three-port circulator (based on dual optical ports) according to Embodiment 5 of the present invention.

detailed description

To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

As shown in FIG. 3 , a low-cost small optical circulator in this embodiment includes a left polarization beam splitter 110 , a magneto-optical rotating plate 120 , a half-wave plate 130 and a right polarization beam splitter 140 arranged in sequence. The upper end surface of the right polarizing beam splitter 140 is coated with a high-reflection film 150 . FIG. 3 also shows a schematic diagram of the optical path of the circulator core formed by the structure; in addition, the rotation angle of the magneto-optical rotating plate 120 is 45°, and the optical axis of the half-wave plate 130 is designed to be 22.5° or 67.5° (combined with FIG. 6 to Figure 9 one); the magneto-optical rotating plate 120 and the half-wave plate 130 constitute a magneto-optical non-reciprocal element, that is, the polarization direction rotates 90° when the beam passes through one side, and the polarization direction remains unchanged when passing through the other side.

4 and 5 are respectively schematic diagrams of dismantling the optical path of the circulator core according to the present invention; the optical signal of channel 1 (ie, the optical signal port I) is incident on the hypotenuse side of the right angle triangular prism 112 of the left polarization controller 110, The interface between the triangular prism 112 and the parallel block 111 is divided into two beams whose polarization directions are perpendicular to each other. After passing through the magneto-optical rotating plate 120 and the half-wave plate 130 in turn, the polarization direction is rotated by 90°, and then combined into a single beam after passing through the right polarization beam splitter 140 , the incident high-reflection film 150; the beam reflected by the high-reflection film 150 is divided into two beams whose polarization directions are perpendicular to each other after passing through the interface of the right-angle prism 141 and the parallel block 142 of the right polarizing beam splitter 140, and then passes through the half-wave plate 130 and the magnetic The polarization direction of the optical rotating plate 120 remains unchanged, and is combined into a single beam after passing through the left polarization beam splitter 110, and then exits through the parallel block 111 side of the left polarization beam splitter 110 and is coupled to channel 2 (ie, the optical signal port II). )middle.

The optical signal of channel 2 (ie, optical signal port II) is incident on the surface of the parallel block 111 of the left polarization controller 110, and is divided into two beams whose polarization directions are perpendicular to each other after passing through the interface between the triangular prism block 112 and the parallel block 111. The polarization direction of the light rotating plate 120 and the half-wave plate 130 is rotated by 90°, and is combined into a single beam after passing through the right polarization beam splitter 140. signal port III).

6 to 9 are respectively schematic diagrams corresponding to the polarization state deflection of the linearly polarized light by the half-wave plate 130 shown in FIG. 4; when the incident light is incident from left to right, the linearly polarized light of 45° on the right rotates into horizontally polarized light ( Figure 6), the left 45° linearly polarized light is rotated to be vertically polarized light (Figure 7); when the incident light is incident from right to left, the vertical linearly polarized light is rotated to the right 45° polarized light (Figure 8, from the right Looking to the left), the horizontal linearly polarized light is rotated to the left 45° polarized light (Figure 9, looking from right to left).

Example 2

As shown in FIG. 10 or FIG. 11 , the low-cost small optical circulator in this embodiment includes a left polarization beam splitter 110 , a magneto-optical rotating plate 120 , a half-wave plate 130 , and a right polarization beam splitter coated with a high-reflection film 150 Circulator core 140 glued together and three

single fiber collimators

160, 170 and 180.

FIG. 10 is a schematic plan view of the light path of the present embodiment, and FIG. 11 is a side view light path schematic view. The optical signal of channel 1 is collimated by the collimator 160 and then enters the left polarization beam splitter 110 of the circulator core, and then passes through the magneto-optical rotating plate 120, the half-wave plate 130, and the right polarization beam splitter 140 in sequence, and then reaches the high reflection film 150. After being reflected by the high-reflection film 150, it passes through the right polarization beam splitter 140, the half-wave plate 130, and the magneto-optical rotating plate 120 in sequence, and then exits through the left polarization beam splitter 110, and is then coupled to the channel 2 through the collimator 170. The optical signal of channel 2 is collimated by the collimator 170 and then enters the left polarization beam splitter 110 of the circulator core, passes through the magneto-optical rotating plate 120, the half-wave plate 130, and the right polarization beam splitter 140 in sequence, and then passes through the collimator. 180 is coupled into channel 3.

Example 3

As shown in FIG. 12 or FIG. 13 , the low-cost small optical circulator in this embodiment includes a left polarization beam splitter 210 , a magneto-optical rotating plate 220 , a half-wave plate 230 , and a right polarization beam splitter coated with a high-reflection film 250 Circulator core 240 glued together and three

dual fiber collimators

260, 270 and 280.

FIG. 12 is a schematic plan view of the light path of the present embodiment, and FIG. 13 is a side view light path schematic view. The optical signal of channel 1 of the circulator 1 is incident through the upper optical fiber of the dual-fiber collimator 260, and after being collimated by the collimator, it enters the left polarization beam splitter 210 of the circulator core and passes through the magneto-optical rotating plate 220 and the half-wave plate in turn. 230. After the right polarization beam splitter 240 reaches the high-reflection film 250, after being reflected by the high-reflection film 250, it passes through the right polarization beam splitter 240, the half-wave plate 230, the magneto-optical rotating plate 220 in turn, and then passes through the left polarization beam splitter 210 Outgoing, then focused and coupled to the lower fiber of the collimator 270; the optical signal of channel 2 of the circulator 1 is incident through the upper fiber of the dual-fiber collimator 270, and after being collimated by the collimator, it enters the left side of the circulator core. The polarization beam splitter 210 passes through the magneto-optical rotating plate 220 , the half-wave plate 230 , and the right polarization beam splitter 240 in sequence, and is coupled to the channel 3 through the lower fiber of the collimator 280 . The optical path of circulator 2 is the same as that of circulator 1, but the incident end of channel 1 is the lower fiber of collimator 260, the exit end of channel 2 is the upper fiber of collimator 270, and the incident end of channel 2 is collimator 270. The lower fiber of the channel 3 is the upper fiber of the collimator 280.

Example 4

As shown in FIG. 14 , the low-cost small optical circulator in this embodiment includes a left polarization beam splitter 310 , a magneto-optical rotating plate 320 , a half-wave plate 330 , and a right polarization beam splitter 340 coated with a high-reflection film 350 glued together The resulting circulator core, single-

fiber collimators

360, 380 and optical port assembly 370. The direction of the optical path of this embodiment is the same as that of the embodiment 1, the difference is that the single-fiber collimator 170 used for the optical signal coupling of the channel 2 in the embodiment 1 is replaced with an optical port assembly 370 .

Example 5

As shown in FIG. 15 , the small optical circulator in this embodiment is based on the two circulator core structures disclosed in Embodiment 1, which specifically includes two circulator cores, two optical ports, and four single-fiber collimators. And a double circulator composed of parallel blocks for optical path turning. The direction of the optical path of a single circulator is the same as that in Example 3, wherein channel 1 of circulator 1 corresponds to single-fiber collimator 450, channel 3 corresponds to single-fiber collimator 440, channel 2 corresponds to optical port 480; channel 1 of circulator 2 corresponds to single-fiber collimator 440 Corresponding to the single-fiber collimator 460 , channel 3 corresponds to the single-fiber collimator 470 , and channel 2 corresponds to the optical port 490 . The parallel block 430 is used for turning and receiving the optical path between the circulator core 420 and the optical port 490 .

The above are the embodiments of the present invention. For those of ordinary skill in the art, according to the teachings of the present invention, without departing from the principle and spirit of the present invention, all equivalent changes and modifications made according to the scope of the patent application of the present invention , substitutions and modifications shall all fall within the scope of the present invention.

Claims

A low-cost small optical circulator is characterized in that: it comprises a left polarization beam splitter, a magneto-optical rotating plate, a half-wave plate and a right polarization beam splitter arranged in sequence, and the upper end surface of the right polarization beam splitter is coated with With high reflective film.
The low-cost small optical circulator according to claim 1, wherein the left polarization beam splitter, the magneto-optical rotating plate, the half-wave plate and the right polarization beam splitter are sequentially glued into one.
The low-cost small optical circulator according to claim 1 or 2, wherein the left polarization beam splitter is formed by gluing a parallel block and a right angle triangular prism, wherein the parallel block of the left polarization beam splitter The lower end face of the left polarizing beam splitter is in an inclined plane structure and is attached to the right angle face of the right angle triangular prism, and the end face of the parallel block of the left polarizing beam splitter close to the magneto-optical rotating plate is attached to the upper part of the magneto-optical rotating plate, and the left polarizing beam splitter The upper part of the inclined surface of the right angle triangular prism is attached to the lower part of the magneto-optical rotating plate; in addition, the right polarizing beam splitter is also made of a parallel block and a right angle triangular prism glued together, and the upper end face of the parallel block of the right polarizing beam splitter It is an inclined plane structure and fits with the inclined plane of its right angle triangular prism, and the end face of the parallel block of the right polarization beam splitter close to the half-wave plate is attached to the lower part of the half wave plate, and the right angle of the right angle prism of the right polarization beam splitter is right angle. The surface is attached to the upper part of the half-wave plate, and the other right-angle surface of the right-angle triangular prism of the right polarizing beam splitter is coated with a high-reflection film.
The low-cost small optical circulator according to claim 3, wherein the rotation angle of the magneto-optical rotating plate is 45°; the design value of the optical axis of the half-wave plate is 22.5° or 67.5°.
The low-cost small optical circulator according to claim 3, wherein the magneto-optical rotating plate cooperates with the half-wave plate to form a non-reciprocal optical path structure, which is used for optical signals passing through one of the directions. The polarization direction is rotated by 90°, and the polarization direction of the optical signal passing in the other direction remains unchanged.
The low-cost small optical circulator according to claim 3, wherein an optical signal port I is formed on the lower part of the inclined plane of the right-angle block of the left polarization beam splitter, and the parallel block of the left polarization beam splitter rotates away from the magneto-optical The end face of the plate forms the optical signal port II, and the end face of the parallel block of the right polarization beam splitter away from the half-wave plate forms the optical signal port III.
The low-cost small optical circulator according to claim 6, wherein the optical circulator further comprises three single-fiber collimators corresponding to the optical signal port I, the optical signal port II and the optical signal port III one-to-one device.
The low-cost small optical circulator according to claim 6, wherein the optical circulator further comprises three dual-fiber collimators corresponding to the optical signal port I, the optical signal port II and the optical signal port III one-to-one The dual-fiber collimator corresponding to the optical signal port I is cross-coupled with the dual-fiber collimator corresponding to the optical signal port II, and the dual-fiber collimator corresponding to the optical signal port II is also connected to the dual-fiber collimator corresponding to the optical signal port III. Fiber collimator cross-coupling.
The low-cost compact optical circulator according to claim 6, wherein the optical circulator further comprises two single-fiber collimators and an optical port assembly; wherein the two single-fiber collimators are respectively connected with the optical The signal port I corresponds to the optical signal port III and is used for the input and output coupling of the optical signal of the optical signal port I and the optical signal port III. The optical port component corresponds to the optical signal port II and is used for the input and output coupling of the optical signal of the optical signal port II. .
A small optical circulator, characterized in that: it comprises two low-cost small optical circulators according to claim 9 arranged in an up and down mirror image; wherein the left polarization beam splitter of one low-cost small optical circulator and its optical port A turning parallel block is arranged between the components.