CN215297734U

CN215297734U - Optical fiber circulator

Info

Publication number: CN215297734U
Application number: CN202120751567.8U
Authority: CN
Inventors: 顾共恩; 张美容; 樊恒志
Original assignee: Anewcom Inc
Current assignee: Anewcom Inc
Priority date: 2021-04-14
Filing date: 2021-04-14
Publication date: 2021-12-24
Anticipated expiration: 2031-04-14

Abstract

The utility model relates to an optical fiber circulator, including ring core, first optical collimator, second optical collimator, the transmitting terminal, the receiving terminal of ring core lie in the same one side of ring core, and the public end of ring core lies in the opposite side of ring core, and the transmitting terminal, the receiving terminal that lie in ring core one side respectively with second optical collimator optical coupling, lie in the public end and the first optical collimator optical coupling of ring core opposite side, the ring core includes first polarization beam splitter, second polarization beam splitter and polarization conversion subassembly, the polarization conversion subassembly is fixed between first polarization beam splitter and second polarization beam splitter, forms a whole after-fixing on the magnetic path again. The utility model discloses an optical fiber circulator assembly degree of difficulty is little, and reliability, stability can be good, the integrated level is high.

Description

Optical fiber circulator

Technical Field

The utility model belongs to the optical communication field, concretely relates to optical fiber circulator.

Background

The optical fiber circulator is a nonreciprocal passive device with multi-port input and output, and is characterized by that when the optical signal is input from designated port, it can only be propagated in the device along the defined sequence, and when the transmission sequence of optical signal is changed, its loss is very large, so that it can implement signal isolation. With the continuous development of optical fiber communication technology, it has become one of the important devices in the present and future optical fiber communication systems.

The most popular circulators at present have the problems of complex packaging, high cost, low integration level and the like.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's defect, provide an optical fiber circulator, its assembly degree of difficulty is little, and reliability, stability can be good, the integrated level is high.

The technical scheme of the utility model is realized like this: the utility model discloses an optical fiber circulator, including ring core, first optical collimator, second optical collimator, the transmitting terminal, the receiving terminal of ring core lie in the same one side of ring core, and the public end of ring core lies in the opposite side of ring core, and the transmitting terminal, the receiving terminal that lie in ring core one side respectively with second optical collimator optical coupling, lie in the public end and the first optical collimator optical coupling of ring core opposite side, the ring core includes first polarization beam splitter, second polarization beam splitter and polarization conversion subassembly, the polarization conversion subassembly is fixed between first polarization beam splitter and second polarization beam splitter, forms a whole after-fixing on the magnetic path again.

Furthermore, the optical fiber circulator further comprises a packaging shell, the circulator core is fixed in the packaging shell, one end of the packaging shell is fixedly connected with the first optical fiber collimator, and the other end of the packaging shell is fixedly connected with the second optical fiber collimator.

The packaging shell is a glass tube, the second optical fiber collimator is fixed at one axial end of the glass tube, and the first optical fiber collimator is fixed at the other axial end of the glass tube; the annular core is positioned between the second optical fiber collimator and the first optical fiber collimator.

Further, the circulator core is a three-port circulator core; the second optical fiber collimator is a double-core collimator, the first optical fiber collimator is a single-core collimator, and the double-core collimator is respectively and correspondingly optically coupled with the transmitting end and the receiving end which are positioned on the same side of the annular core.

Further, a first polarization conversion assembly and a second polarization conversion assembly are fixed between the first polarization splitting prism and the second polarization splitting prism, the first polarization splitting prism is provided with a first light passing surface S1, a polarization splitting surface, a reflecting surface S2, a second light passing surface S3 and a third light passing surface S5, the second polarization splitting prism is provided with a first light passing surface SS5, a first polarization splitting surface SS4, a second polarization splitting surface SS2, a second light passing surface SS1, a third light passing surface SS3 and a second light passing surface SS6, when P light enters from the first port, the P light enters from the first light passing surface SS5 of the second polarization splitting prism, is transmitted through the first polarization splitting surface SS4 of the second polarization splitting prism and then exits through the second light passing surface SS1 thereof, the P light exiting from the second light passing surface SS1 of the second polarization splitting prism passes through the first polarization conversion assembly and then enters from the third light passing surface S5 of the first polarization splitting prism, the P light incident from the first port is transmitted to the second port and does not change the polarization state when passing through the first polarization conversion component; when the P light enters from the second port, the P light entering from the first light-passing surface S1 of the first polarization splitting prism is transmitted through the polarization splitting surface of the first polarization splitting prism and then exits from the third light-passing surface S5 thereof to the first polarization conversion assembly, the first polarization conversion assembly is used for converting the P light entering from the second port into the S light and then exits to the second light-passing surface SS1 of the second polarization splitting prism, the first polarization splitting surface SS4 of the second polarization splitting prism is used for reflecting the S light exiting from the first polarization conversion assembly to the second polarization splitting surface SS2 of the second polarization splitting prism, and then the S light is reflected by the second polarization splitting surface SS2 of the second polarization splitting prism and then exits from the third light-passing surface SS3 thereof to the third port and then is output; when the S light enters from the second port, the S light entering from the first light-passing surface S1 of the first polarization splitting prism reaches the reflection surface of the first polarization splitting prism after being reflected by the polarization splitting surface of the first polarization splitting prism, and exits from the second light-passing surface S3 of the first polarization splitting prism after being reflected by the reflection surface of the first polarization splitting prism to the second polarization conversion assembly, the second polarization conversion assembly is configured to convert the S light entering from the second port into the P light and then exits to the fourth light-passing surface SS6 of the second polarization splitting prism, and the S light entering from the fourth light-passing surface SS6 of the second polarization splitting prism and exiting from the third light-passing surface SS3 of the second polarization splitting prism after being transmitted by the second polarization splitting surface SS2 of the second polarization splitting prism is then exits to the third port and then outputs; the reflecting surface of the first polarization beam splitter prism is a total reflection surface.

Furthermore, the first polarization splitting prism is a trapezoidal polarization splitting prism formed by gluing a PBS polarization splitting right-angle triangular prism and a PBS polarization splitting parallelogram prism; the bonding surface of the PBS polarization splitting parallelogram prism of the first polarization splitting prism and the PBS polarization splitting right-angle triangular prism is a polarization splitting surface, and the reflecting surface S2 of the first polarization splitting prism is a surface parallel to and corresponding to the bonding surface on the PBS polarization splitting parallelogram prism; the second polarization splitting prism is a square PBS polarization splitting prism formed by gluing two PBS polarization splitting right-angle triangular prisms and one PBS polarization splitting parallelogram prism; the gluing surfaces of the two PBS polarization splitting right-angle triangular prisms of the second polarization splitting prism and the PBS polarization splitting parallelogram prism are polarization splitting surfaces; and the polarization beam splitting surface is plated with a polarization beam splitting film.

Further, the annular core is a four-port annular core; the second optical fiber collimator is a three-core collimator, the first optical fiber collimator is a single-core collimator, and the three-core collimator is respectively and correspondingly optically coupled with the transmitting end, the first receiving end and the second receiving end which are positioned on the same side of the annular core.

Furthermore, the first polarization splitting prism and the second polarization splitting prism are respectively provided with a first light passing surface, a polarization splitting surface, a total reflection surface, a second light passing surface and a third light passing surface, wherein the polarization splitting surface of the first polarization splitting prism is used for reflecting the second polarized light incident from the second port to the total reflection surface thereof, and the second polarized light is emitted from the second light passing surface to the fourth port for output after being reflected by the total reflection surface of the first polarization splitting prism; the polarization splitting surface of the first polarization splitting prism is used for transmitting the first polarized light incident from the second port and then transmitting the first polarized light to the polarization conversion assembly through the third light passing surface of the first polarization splitting prism, the polarization conversion assembly is used for performing polarization conversion on the first polarized light incident from the second port and then emitting the first polarized light to the first light passing surface of the second polarization splitting prism and reaching the polarization splitting surface of the second polarization splitting prism, and the polarization splitting surface of the second polarization splitting prism is used for reflecting the polarized light after the polarization conversion to the total reflection surface of the second polarization splitting prism and then emitting the second polarized light to the third port from the second light passing surface of the second polarization splitting prism after the reflection of the total reflection surface of the second polarization splitting prism; the first polarized light signal incident from the first port is incident to the polarization beam splitting surface of the second polarization beam splitting prism from the third light passing surface of the second polarization beam splitting prism, is transmitted by the polarization beam splitting surface of the second polarization beam splitting prism, then reaches the polarization beam splitting surface of the first polarization beam splitting prism through the polarization conversion assembly, and is transmitted by the polarization beam splitting surface of the first polarization beam splitting prism, and then is emitted from the first light passing surface of the first polarization beam splitting prism to the second port for output; when the first polarized light signal incident from the first port is transmitted to the second port, the polarization state of the first polarized light signal is not changed after passing through the polarization conversion component.

Furthermore, the first polarization splitting prism and the second polarization splitting prism are both trapezoidal polarization splitting prisms formed by gluing a PBS polarization splitting right-angle triangular prism and a PBS polarization splitting parallelogram prism; the bonding surface of the PBS polarization splitting parallelogram prism of the first polarization splitting prism and the PBS polarization splitting right-angle triangular prism is a polarization splitting surface, and the reflecting surface S2 of the first polarization splitting prism is a surface parallel to and corresponding to the bonding surface on the PBS polarization splitting parallelogram prism; and the polarization beam splitting surface is plated with a polarization beam splitting film.

Furthermore, the polarization conversion assembly is adhered between the first polarization beam splitter prism and the second polarization beam splitter prism to form a whole and then adhered to the magnetic block.

Further, the polarization conversion assembly includes a faraday magneto-rotation plate and a half-wave plate.

The utility model discloses following beneficial effect has at least: the utility model discloses the transmitting terminal, the receiving terminal of the ring core of optic fibre circulator are located the same one side of ring core, and the public end of ring core is located the opposite side of ring core, and transmitting terminal, the receiving terminal that are located ring core one side respectively with second fiber collimator optical coupling, the public end that is located ring core opposite side and first fiber collimator optical coupling, ring core include first polarization beam splitter prism, second polarization beam splitter prism and polarization conversion subassembly, polarization conversion subassembly is fixed between first polarization beam splitter prism and second polarization beam splitter prism, forms a whole after fix on the magnetic path again, and the assembly degree of difficulty is little, and reliability stability can be good, and the integrated level is high, and the volume reduces.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an optical fiber circulator according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a four-port circulator core according to an embodiment of the present invention;

FIG. 3 is a schematic plan optical diagram of a four port circulator core according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a three-port circulator core according to an embodiment of the present invention;

FIG. 5 is a schematic plan optical diagram of a three port toroid core according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a trapezoidal polarization splitting prism according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a square polarization splitting prism according to an embodiment of the present invention.

In the drawing, 1 is a package housing, 2 is an annular core, 21 is a first polarization beam splitter prism, 22 is a faraday magnetic rotation plate, 23 is a half-wave plate, 24 is a second polarization beam splitter prism, 25 is a magnetic block, 26 is a polarization conversion assembly, 261 is a first polarization conversion assembly, 262 is a second polarization conversion assembly, 3 is a first optical fiber collimator, and 4 is a second optical fiber collimator.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the present invention.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of the present invention, "a plurality" or "a plurality" means two or more unless otherwise specified.

Example one

Referring to fig. 1 to 3, the embodiment of the utility model provides an optical fiber circulator, including annular core 2, first optical collimator 3, second optical collimator 4, the transmitting terminal of annular core, receiving terminal are located the same one side of annular core, and the public end of annular core is located the opposite side of annular core, and transmitting terminal, the receiving terminal that are located annular core one side are optical coupling with second optical collimator 4 respectively, and the public end that is located annular core opposite side is optical coupling with first optical collimator 3, annular core 2 includes first polarization beam splitter prism 21, second polarization beam splitter prism 24 and polarization conversion module 26, polarization conversion module fixes between first polarization beam splitter and second polarization beam splitter, forms a whole after fix on the magnetic path again. Furthermore, the polarization conversion assembly is adhered between the first polarization beam splitter prism and the second polarization beam splitter prism to form a whole and then adhered to the magnetic block. One or two groups of polarization conversion components can be arranged between the first polarization beam splitter prism and the second polarization beam splitter prism according to requirements.

Further, the polarization conversion assembly includes a faraday magneto-rotation plate 22 and a half-wave plate 23.

Furthermore, the optical fiber circulator further comprises a packaging shell 1, the circulator core is fixed in the packaging shell 1, one end of the packaging shell 1 is fixedly connected with the first optical fiber collimator, and the other end of the packaging shell is fixedly connected with the second optical fiber collimator.

The packaging shell is a glass tube, the second optical fiber collimator is fixed at one axial end of the glass tube, and the first optical fiber collimator is fixed at the other axial end of the glass tube; the annular core is positioned between the second optical fiber collimator and the first optical fiber collimator. The first optical fiber collimator and the second optical fiber collimator of the embodiment can be fixedly connected with the glass tube through fixing glue, and the glass tube is packaged. And the magnetic block of the annular core is fixed in the glass tube through fixing glue.

Adopt the utility model discloses a four port ring shape wares, its first port, third port, fourth port are located the homonymy, and the homonymy can be accomplished with the receiving port to the transmission port promptly. The first port and the second port are respectively positioned on the left side and the right side.

Further, the magnetic block 25 adopts a neodymium iron boron magnet or a similar permanent magnet, and the effective magnetic field intensity provided is 1000Gs gauss. The bonding surfaces of the upper end surface and the lower end surface of the magnetic block 25 preferably need to be polished.

Further, the polarization conversion assembly 26 includes a faraday magneto-rotation plate 22 and a half-wave plate 23; and a first light passing surface on one side of the Faraday magneto-rotation plate 22 is adhered to a third light passing surface of the first polarization beam splitter prism 21, a second light passing surface on the other side of the Faraday magneto-rotation plate 22 is adhered to a light passing surface on one side of the half-wave plate 23, and a light passing surface on the other side of the half-wave plate 23 is adhered to a first light passing surface of the second polarization beam splitter prism 24.

The optical path is from the second port to the first port, the Faraday rotation plate and the half-wave plate have the same optical rotation direction under the action of a magnetic field, and the polarization state of light is changed (45 degrees +45 degrees) by 90 degrees; the optical path from the first port to the second port is opposite to the optical path from the second port to the first port, and the faraday and half-wave plates are opposite in optical rotation direction under the action of the magnetic field, so that the polarization state of the light is changed (45 ° + (-45 °)) by 0 ° which is equivalent to no change of the polarization state.

The bottom surface of the faraday magnetic rotation plate 22 of the present embodiment is bonded to the upper end surface of the magnetic block 25.

The angle of rotation of the faraday rotator plate 22 in this embodiment is 45 deg., meaning that the polarization of light passing through it is rotated by 45 deg..

The light-passing surfaces on both sides of the half-wave plate 23 may be polished and then bonded to other members. In this embodiment, the upper end surface and the bottom surface of the half-wave plate 23 may be first finely ground, and then the bottom surface of the half-wave plate 23 may be bonded to the upper end surface of the magnetic block 25. The optical axis of the half-wave plate is 22.5 °.

Further, the first light-passing surface S1 of the first polarization splitting prism 21 is AR-coated; the second light-passing surface S3 of the first polarization splitting prism 21 is coated with an AR film; the third light passing surface S5 of the first polarization beam splitter prism 21 is bonded with the Faraday magneto-rotation sheet 22, and when bonding, a glue coating film is bonded again or a glue with a refractive index matched with the glue coating film is selected for bonding again; the polarization splitting surface S4/S6 of the first polarization splitting prism 21 is coated with a polarization splitting film (PBS film, P light transmission, S light reflection, this multilayer dielectric film satisfies brewster' S condition) for the first polarization light (P light) transmission and the second polarization light (S light) reflection. The first polarization splitting prism 21 has polished S1, S2, S3, S4, S5, S6, and S7 surfaces, S3 and S5 forming a plane, S1 surface being parallel to S3 surface and S5 surface, and S2 surface being parallel to S4 surface.

Further, a first light-passing surface S1 of the second polarization beam splitter prism 24 is bonded with the half-wave plate 23, and during bonding, a glue coating film is bonded again or a glue with a refractive index matched with the glue coating film is selected for bonding again; a second light-passing surface S3 of the second polarization splitting prism 24 is coated with an AR film; a third light passing surface S5 of the second polarization splitting prism 24 is coated with an AR film; the polarization splitting surface S4/S6 of the second polarization splitting prism 24 is coated with a polarization splitting film (PBS film, P light transmission, S light reflection, this multilayer dielectric film satisfies brewster' S condition) for the first polarization light (P light) transmission and the second polarization light (S light) reflection. The second polarization beam splitter prism 24 has polished S1, S2, S3, S4, S5, S6 and S7 surfaces, the S3 and S5 are in a plane, the S1 is parallel to the S3 and S5, and the S2 is parallel to the S4 surface.

Preferably, the first polarization splitting prism 21 and the second polarization splitting prism 24 are both trapezoidal polarization splitting prisms formed by gluing one PBS polarization splitting right-angle triangular prism and one PBS polarization splitting parallelogram prism; the upper end surface S2 of the PBS polarization light splitting parallelogram prism is the total reflection surface, and the left side surface S1 of the PBS polarization light splitting parallelogram prism is the first light passing surface; the right side surface S3 of the PBS polarization splitting parallelogram prism is the second light-passing surface; the combined surface formed by gluing the lower end surface S4 of the PBS polarization splitting parallelogram prism and the inclined surface S6 of the PBS polarization splitting right-angle triangular prism is a polarization splitting surface; the right-angle side surface S5 of the PBS polarization splitting right-angle triangular prism is the third light-passing surface, and the right-angle bottom surface S7 of the PBS polarization splitting right-angle triangular prism is used for being bonded with the magnetic block 25. In this embodiment, the lengths of the left and right sides of the PBS polarizing splitting parallelogram prism of the first polarizing splitting prism 21 are greater than the lengths of the left and right sides of the PBS polarizing splitting parallelogram prism of the second polarizing splitting prism 24.

The combination surfaces of the first polarization beam splitter prism 21, the second polarization beam splitter prism 24, the Faraday magneto-rotation plate 22 and the half-wave plate 23 are light-passing surfaces, when the two components are bonded, the glue coating film is bonded again or bonded by adopting glue with matched refractive index, no separated gap exists, and the light path loss is small. The first polarization beam splitter prism 21, the second polarization beam splitter prism 24, the Faraday magnetic rotation plate 22 and the half-wave plate 23 of the embodiment are adhered into a whole by glue and then adhered to the magnetic block 25, so that the assembly difficulty is small, the reliability and stability performance are good, and the volume is reduced.

Referring to fig. 3, an optical signal P is incident to the second Port2 from the first Port1, the P light is transmitted through the S4 polarization splitting surface of the second polarization splitting prism 24, passes through the half-wave plate and the faraday rotator 22, and under the action of a magnetic field, the optical rotation directions of the half-wave plate and the faraday rotator are opposite, so that the polarization state is not changed, and the S4 polarization splitting surface reaching the first polarization splitting prism 21 is transmitted and output from the second Port 2; if a P optical signal is input from the second Port2 in reverse, after the P light is transmitted through the S4 polarization splitting surface of the first polarization splitting prism 21, the magnetic pole of the magnetic block 25 is opposite to the direction from the first Port to the second Port, the optical rotation angles of the faraday magnetic rotation plate 22 and the half-wave plate are the same, the first polarization light is changed into a second polarization light signal, the second polarization light signal is reflected from the S4 polarization splitting surface of the second polarization splitting prism 24, and then the second polarization light signal is reflected by the S2 polarization splitting surface to reach the third Port3, and the optical signal cannot be output from the first Port 1; if the optical signal S light is incident from the second Port2 optical transmission Port, the S light is reflected by the S4 polarization splitting surface of the first polarization splitting prism 21, and then reflected by the S2 total reflection surface of the first polarization splitting prism 21, and is output from the fourth Port4 of the S3 surface, so that the output optical signal of one Port is added from the second Port2 to the fourth Port4, and further, the light cannot be output from the second Port2 to the first Port 1. It is explained that the optical signal inputted from the second Port2 can be outputted only from the third Port3 and the fourth Port4, but not from the first Port1, so that the purpose of unidirectional transmission of the optical signal is achieved, and an output optical signal for receiving the fourth Port4 is added.

Example two

Referring to fig. 4 to 7, the difference between the present embodiment and the first embodiment is: the toroidal core 2 of the present embodiment is a three-port toroidal core; the second optical fiber collimator 4 is a double-core collimator, the first optical fiber collimator 3 is a single-core collimator, and the double-core collimator is respectively and correspondingly optically coupled with the transmitting end and the receiving end which are positioned on the same side of the annular core.

A specific embodiment of a three-port toroidal core is given below.

A first polarization conversion assembly 261 and a second polarization conversion assembly 262 are fixed between the first polarization beam splitter prism 21 and the second polarization beam splitter prism 24, the first polarization beam splitter prism 21 is provided with a first light passing surface S1, a polarization beam splitting surface, a reflection surface S2, a second light passing surface S3 and a third light passing surface S5, the second polarization beam splitter prism 24 is provided with a first light passing surface SS5, a first polarization beam splitting surface SS4, a second polarization beam splitting surface SS2, a second light passing surface SS1, a third light passing surface SS 539 3 and a fourth light passing surface SS6, when P light enters from the first port, the P light enters from the first light passing surface SS5 of the second polarization beam splitter prism, passes through the first polarization beam splitting surface SS4 of the second polarization beam splitter prism and then is emitted through the second light passing surface SS1, the P light emitted from the second light passing surface SS1 of the second polarization beam splitter prism passes through the first polarization beam splitter assembly and then enters from the third light passing surface S5 of the first polarization beam splitter prism, the P light incident from the first port is transmitted to the second port and does not change the polarization state when passing through the first polarization conversion component; when the P light enters from the second port, the P light entering from the first light-passing surface S1 of the first polarization splitting prism is transmitted through the polarization splitting surface of the first polarization splitting prism and then exits from the third light-passing surface S5 thereof to the first polarization conversion assembly, the first polarization conversion assembly is used for converting the P light entering from the second port into the S light and then exits to the second light-passing surface SS1 of the second polarization splitting prism, the first polarization splitting surface SS4 of the second polarization splitting prism is used for reflecting the S light exiting from the first polarization conversion assembly to the second polarization splitting surface SS2 of the second polarization splitting prism, and then the S light is reflected by the second polarization splitting surface SS2 of the second polarization splitting prism and then exits from the third light-passing surface SS3 thereof to the third port and then is output; when the S light enters from the second port, the S light entering from the first light-passing surface S1 of the first polarization splitting prism reaches the reflection surface of the first polarization splitting prism after being reflected by the polarization splitting surface of the first polarization splitting prism, and exits from the second light-passing surface S3 of the first polarization splitting prism after being reflected by the reflection surface of the first polarization splitting prism to the second polarization conversion assembly, the second polarization conversion assembly is configured to convert the S light entering from the second port into the P light and then exits to the fourth light-passing surface SS6 of the second polarization splitting prism, and the S light entering from the fourth light-passing surface SS6 of the second polarization splitting prism and exiting from the third light-passing surface SS3 of the second polarization splitting prism after being transmitted by the second polarization splitting surface SS2 of the second polarization splitting prism is then exits to the third port and then outputs; the reflecting surface of the first polarization beam splitter prism is a total reflection surface.

Furthermore, the first polarization splitting prism is a trapezoidal polarization splitting prism formed by gluing a PBS polarization splitting right-angle triangular prism and a PBS polarization splitting parallelogram prism; the bonding surface of the PBS polarization splitting parallelogram prism of the first polarization splitting prism and the PBS polarization splitting right-angle triangular prism is a polarization splitting surface, and the reflecting surface S2 of the first polarization splitting prism is a surface parallel to and corresponding to the bonding surface on the PBS polarization splitting parallelogram prism; the second polarization splitting prism is a square PBS polarization splitting prism formed by gluing two PBS polarization splitting right-angle triangular prisms and one PBS polarization splitting parallelogram prism; the gluing surfaces of the two PBS polarization splitting right-angle triangular prisms of the second polarization splitting prism and the PBS polarization splitting parallelogram prism are polarization splitting surfaces; the polarization splitting surface is coated with a polarization splitting film (P light transmission and S light reflection, and the multilayer dielectric film meets the Brewster condition).

As shown in fig. 5, which is a schematic plan optical diagram of the present design, an optical signal P enters a Port2 from a Port1 optical transmission Port, the P is transmitted through a square polarization beam splitter S4 polarization beam splitting plane, passes through a half-wave plate and a faraday magneto-rotation plate, reaches a trapezoidal polarization beam splitter S4 polarization beam splitting plane, and is transmitted and output from a Port 2; if the P optical signal is input from the Port2 in reverse, after the P light is transmitted through the polarization beam splitting surface of the trapezoidal polarization beam splitter prism S4, the magnetic poles of the magnetic blocks are reversed, and through the rotation of the Faraday magnetic rotation plate and the half-wave plate, the optical signal is reflected from the polarization beam splitting surface of the square polarization beam splitter prism S4 and then reflected through the polarization beam splitting surface of the S2 to reach the Port3, and the optical signal cannot be output from the Port 1; if the optical signal S light is incident from the Port2 optical transmission Port, the S light is reflected by the S4 polarization splitting surface of the trapezoidal polarization splitting prism, reflected by the S2 total reflection surface of the trapezoidal polarization splitting prism, emitted from the S3 surface, and then optically rotated by the Faraday magneto-optical rotation plate and the half-wave plate, the output optical signal from the Port3 is transmitted by the S2 surface of the square polarization splitting prism and cannot be output from the Port1, further, the optical signal input from the Port2 can only be output from the Port3 but cannot be output from the Port1, and therefore the purpose of unidirectional transmission of the optical signal is achieved.

Of course, the three-port ring core of the present invention is not limited to the above-mentioned embodiments, and can be adjusted as needed. If two groups of polarization conversion components between the first polarization splitting prism and the second polarization splitting prism are adjusted to be one group of polarization conversion components, the second polarization splitting prism can be replaced by a parallelogram PBS polarization splitting prism formed by gluing two PBS polarization splitting parallelogram prisms, and the gluing surfaces of the two PBS polarization splitting parallelogram prisms are polarization splitting surfaces. Two surfaces of the two PBS polarization splitting parallelogram prisms, which are parallel to and correspond to the gluing surface, are reflecting surfaces.

EXAMPLE III

The embodiment further comprises an isolator, wherein the isolator is fixed on a light passing surface corresponding to the first port on the second polarization splitting prism, so that light incident from the first port is transmitted to the second polarization splitting prism through the isolator. The isolator may prevent the optical signal from returning to the first port, increasing isolation. Other technical features of the present embodiment are the same as those of the first embodiment or the second embodiment.

The utility model discloses improve the circulator core of current optic fibre circulator, other technical characteristics can refer to current optic fibre circulator. The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fiber optic circulator, comprising: the device comprises an annular core, a first optical fiber collimator and a second optical fiber collimator, wherein a transmitting end and a receiving end of the annular core are positioned on the same side of the annular core, a common end of the annular core is positioned on the other side of the annular core, the transmitting end and the receiving end positioned on one side of the annular core are respectively optically coupled with the second optical fiber collimator, the common end positioned on the other side of the annular core is optically coupled with the first optical fiber collimator, the annular core comprises a first polarization beam splitter prism, a second polarization beam splitter prism and a polarization conversion assembly, and the polarization conversion assembly is fixed between the first polarization beam splitter prism and the second polarization beam splitter prism to form a whole and then fixed on a magnetic block.

2. The fiber optic circulator of claim 1 wherein: the optical fiber coupler is characterized by further comprising a packaging shell, the annular core is fixed in the packaging shell, one end of the packaging shell is fixedly connected with the first optical fiber collimator, and the other end of the packaging shell is fixedly connected with the second optical fiber collimator.

3. The fiber optic circulator of claim 1 wherein: the annular core is a three-port annular core; the second optical fiber collimator is a double-core collimator, the first optical fiber collimator is a single-core collimator, and the double-core collimator is respectively and correspondingly optically coupled with the transmitting end and the receiving end which are positioned on the same side of the annular core.

4. The fiber optic circulator of claim 3 wherein: a first polarization conversion assembly and a second polarization conversion assembly are fixed between the first polarization splitting prism and the second polarization splitting prism, the first polarization splitting prism is provided with a first light passing surface S1, a polarization splitting surface, a reflecting surface S2, a second light passing surface S3 and a third light passing surface S5, the second polarization splitting prism is provided with a first light passing surface SS5, a first polarization splitting surface SS4, a second polarization splitting surface SS2, a second light passing surface SS1, a third light passing surface SS3 and a fourth light passing surface SS6, when P light enters from the first port, the P light enters from the first light passing surface SS5 of the second polarization splitting prism, is transmitted through the first polarization splitting surface SS4 of the second polarization splitting prism and then exits through the second light passing surface SS1 thereof, the P light exiting from the second light passing surface SS1 of the second polarization splitting prism enters from the third light passing surface S5 of the first polarization splitting prism after passing through the first polarization conversion assembly, the P light incident from the first port is transmitted to the second port and does not change the polarization state when passing through the first polarization conversion component; when the P light enters from the second port, the P light entering from the first light-passing surface S1 of the first polarization splitting prism is transmitted through the polarization splitting surface of the first polarization splitting prism and then exits from the third light-passing surface S5 thereof to the first polarization conversion assembly, the first polarization conversion assembly is used for converting the P light entering from the second port into the S light and then exits to the second light-passing surface SS1 of the second polarization splitting prism, the first polarization splitting surface SS4 of the second polarization splitting prism is used for reflecting the S light exiting from the first polarization conversion assembly to the second polarization splitting surface SS2 of the second polarization splitting prism, and then the S light is reflected by the second polarization splitting surface SS2 of the second polarization splitting prism and then exits from the third light-passing surface SS3 thereof to the third port and then is output; when the S light enters from the second port, the S light entering from the first light-passing surface S1 of the first polarization splitting prism reaches the reflection surface of the first polarization splitting prism after being reflected by the polarization splitting surface of the first polarization splitting prism, and exits from the second light-passing surface S3 of the first polarization splitting prism after being reflected by the reflection surface of the first polarization splitting prism to the second polarization conversion assembly, the second polarization conversion assembly is configured to convert the S light entering from the second port into the P light and then exits to the fourth light-passing surface SS6 of the second polarization splitting prism, and the S light entering from the fourth light-passing surface SS6 of the second polarization splitting prism and exiting from the third light-passing surface SS3 of the second polarization splitting prism after being transmitted by the second polarization splitting surface SS2 of the second polarization splitting prism is then exits to the third port and then outputs; the reflecting surface of the first polarization beam splitter prism is a total reflection surface.

5. The fiber optic circulator of claim 3 wherein: the first polarization splitting prism is a trapezoidal polarization splitting prism formed by gluing a PBS polarization splitting right-angle triangular prism and a PBS polarization splitting parallelogram prism; the bonding surface of the PBS polarization splitting parallelogram prism of the first polarization splitting prism and the PBS polarization splitting right-angle triangular prism is a polarization splitting surface, and the reflecting surface S2 of the first polarization splitting prism is a surface parallel to and corresponding to the bonding surface on the PBS polarization splitting parallelogram prism; the second polarization splitting prism is a square PBS polarization splitting prism formed by gluing two PBS polarization splitting right-angle triangular prisms and one PBS polarization splitting parallelogram prism; the gluing surfaces of the two PBS polarization splitting right-angle triangular prisms of the second polarization splitting prism and the PBS polarization splitting parallelogram prism are polarization splitting surfaces; and the polarization beam splitting surface is plated with a polarization beam splitting film.

6. The fiber optic circulator of claim 1 wherein: the annular core is a four-port annular core; the second optical fiber collimator is a three-core collimator, the first optical fiber collimator is a single-core collimator, and the three-core collimator is respectively and correspondingly optically coupled with the transmitting end, the first receiving end and the second receiving end which are positioned on the same side of the annular core.

7. The fiber optic circulator of claim 6 wherein: the first polarization beam splitter prism and the second polarization beam splitter prism are respectively provided with a first light passing surface, a polarization beam splitting surface, a total reflection surface, a second light passing surface and a third light passing surface, and the polarization beam splitting surface of the first polarization beam splitter prism is used for reflecting the second polarized light incident from the second port to the total reflection surface thereof, reflecting the second polarized light by the total reflection surface of the first polarization beam splitter prism and then emitting the second polarized light from the second light passing surface thereof to the fourth port for output; the polarization splitting surface of the first polarization splitting prism is used for transmitting the first polarized light incident from the second port and then transmitting the first polarized light to the polarization conversion assembly through the third light passing surface of the first polarization splitting prism, the polarization conversion assembly is used for performing polarization conversion on the first polarized light incident from the second port and then emitting the first polarized light to the first light passing surface of the second polarization splitting prism and reaching the polarization splitting surface of the second polarization splitting prism, and the polarization splitting surface of the second polarization splitting prism is used for reflecting the polarized light after the polarization conversion to the total reflection surface of the second polarization splitting prism and then emitting the second polarized light to the third port from the second light passing surface of the second polarization splitting prism after the reflection of the total reflection surface of the second polarization splitting prism; the first polarized light signal incident from the first port is incident to the polarization beam splitting surface of the second polarization beam splitting prism from the third light passing surface of the second polarization beam splitting prism, is transmitted by the polarization beam splitting surface of the second polarization beam splitting prism, then reaches the polarization beam splitting surface of the first polarization beam splitting prism through the polarization conversion assembly, and is transmitted by the polarization beam splitting surface of the first polarization beam splitting prism, and then is emitted from the first light passing surface of the first polarization beam splitting prism to the second port for output; when the first polarized light signal incident from the first port is transmitted to the second port, the polarization state of the first polarized light signal is not changed after passing through the polarization conversion component.

8. The fiber optic circulator of claim 7 wherein: the first polarization beam splitter prism and the second polarization beam splitter prism are both trapezoidal polarization beam splitter prisms formed by gluing a PBS polarization beam splitter right-angle triangular prism and a PBS polarization beam splitter parallelogram prism; the bonding surface of the PBS polarization splitting parallelogram prism of the first polarization splitting prism and the PBS polarization splitting right-angle triangular prism is a polarization splitting surface, and the reflecting surface S2 of the first polarization splitting prism is a surface parallel to and corresponding to the bonding surface on the PBS polarization splitting parallelogram prism; and the polarization beam splitting surface is plated with a polarization beam splitting film.

9. The fiber optic circulator of claim 1 wherein: the polarization conversion assembly is adhered between the first polarization beam splitter prism and the second polarization beam splitter prism to form a whole and then adhered to the magnetic block.

10. The fiber optic circulator of claim 1 or 9, wherein: the polarization conversion assembly comprises a Faraday magneto-rotation plate and a half-wave plate.