CN111694100A - Polarization-independent small-sized integrated free space isolator - Google Patents
Polarization-independent small-sized integrated free space isolator Download PDFInfo
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- CN111694100A CN111694100A CN201910188534.4A CN201910188534A CN111694100A CN 111694100 A CN111694100 A CN 111694100A CN 201910188534 A CN201910188534 A CN 201910188534A CN 111694100 A CN111694100 A CN 111694100A
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- 238000002955 isolation Methods 0.000 abstract description 16
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/27—Optical coupling means with polarisation selective and adjusting means
- G02B6/2746—Optical coupling means with polarisation selective and adjusting means comprising non-reciprocal devices, e.g. isolators, FRM, circulators, quasi-isolators
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/27—Optical coupling means with polarisation selective and adjusting means
- G02B6/2753—Optical coupling means with polarisation selective and adjusting means characterised by their function or use, i.e. of the complete device
- G02B6/2793—Controlling polarisation dependent loss, e.g. polarisation insensitivity, reducing the change in polarisation degree of the output light even if the input polarisation state fluctuates
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/34—Optical coupling means utilising prism or grating
Abstract
The invention discloses a polarization-independent small-sized integrated free space isolator which comprises a first polarization light splitting component, a polarization rotating mechanism and a second polarization light splitting component, wherein the first polarization light splitting component, the polarization rotating mechanism and the second polarization light splitting component are sequentially arranged along the direction of a light path; aiming at the limitation problems that the existing isolator has poor isolation effect or causes great insertion loss to unpolarized light under the condition that the polarization state of input signal light is random or unpolarized light, the scheme provides an isolator scheme which can be suitable for polarized light or unpolarized light as light signal input, namely a polarization-independent free space isolator, namely, the difference loss of the isolator can be very low no matter whether the incident light is polarized or not, and the performance index of the isolation degree cannot be influenced; in addition, the scheme of the invention also has the advantages of small volume, integrated structure, easy processing and mass production, low cost, high reliability and the like.
Description
Technical Field
The invention relates to the field of optical communication devices, in particular to a polarization-independent small-sized integrated free space isolator.
Background
In optical communication, signal light passes through many different optical interfaces during transmission from a light source to a receiver, and at each optical interface, reflection occurs to different degrees, and return light generated by the reflection finally returns to the light source along a light path. When the intensity of the return light is accumulated to a certain degree, the light source is unstable, and the problems of frequency drift, amplitude variation and the like are caused, so that the normal operation of the whole system is influenced, which becomes an important problem to be solved. This results in a non-reciprocal passive device, i.e. an optical isolator, which only allows light to propagate in the forward direction of the optical path.
Optical isolators are a very important class of passive devices in fiber optic communications. Such devices allow light to be transmitted only in the forward direction, while blocking light transmitted in the reverse direction, and function similarly to diodes in electronics. Therefore, the optical isolator is widely used in the processes of transmitting, amplifying, transmitting and the like of optical signals as one of the main basic components of optical communication.
The existing free-space optical isolator has the main structure as shown in fig. 1 or 2, which are a single-stage optical isolator and a double-stage optical isolator, respectively. In fig. 1, for a single-stage optical isolator, the light transmitting optical axes of the polarizers 1 and 3 at two ends form an included angle of 45 degrees, the middle is a 45-degree rotating plate 2, the rotating plate can be provided with a magnetic field or an external magnetic field, and forward conduction and reverse isolation can be realized according to the nonreciprocal characteristic of the rotating plate; in fig. 2, the dual-stage isolator is composed of polarizers 1, 3, 5 and two 45 ° rotators 2, 4, the light transmission optical axes of the polarizers 3 and 5 form an included angle of 45 ° and 90 ° respectively with respect to the polarizer 1, the rotators 2, 4 can be self-contained magnetic field or externally-added magnetic field, forward conduction and reverse isolation can be realized according to the nonreciprocal characteristic of the rotators, and the dual-stage isolator has higher isolation degree than the single-stage isolator.
Because the existing free space isolator is designed for polarized light at the incident end, if the incident end is unpolarized light, only optical signals of components parallel to the transmission direction of the polaroid are allowed to be transmitted, which causes very high insertion loss to the unpolarized light; especially, when the transmitting end is output from a single-sided optical fiber or a multimode optical fiber, the polarization of light is random, and the existing free space isolator structure cannot be used.
Disclosure of Invention
In view of the above-mentioned problems, it is an object of the present invention to provide a polarization independent small integrated free space isolator that is small in size, highly integrated in structure, easy to process, low in cost, highly reliable in use, and suitable for mass production.
In order to achieve the technical purpose, the invention adopts the technical scheme that:
the utility model provides a polarization is irrelevant small-size integrates free space isolator which characterized in that: the polarization beam splitter comprises a first polarization beam splitting component, a polarization rotating mechanism and a second polarization beam splitting component which are sequentially arranged along the direction of a light path;
the first polarization light splitting assembly comprises a first 45-degree oblique square prism and a first 45-degree right-angle prism, wherein the upper end face of the first 45-degree oblique square prism is plated or not plated with a high-reflection film, and the lower end face of the first 45-degree oblique square prism is plated with a polarization light splitting film and is attached and fixed with the inclined plane of the first 45-degree right-angle prism into a whole;
the second polarization beam splitting assembly comprises a second 45-degree oblique prism and a second 45-degree right-angle prism, wherein a polarization beam splitting film is arranged on the upper end surface or the lower end surface of the second 45-degree oblique prism and is fixedly integrated with the inclined surface of the second 45-degree right-angle prism in an attaching mode, and a high reflection film is plated or not plated on the end surface, far away from the polarization beam splitting film, of the second polarization beam splitting assembly.
As one of the preferable implementation structures of the polarization rotation mechanism, the polarization rotation mechanism comprises a 45-degree half-wave plate, a glass flat plate, a 90-degree polarizer, a 45-degree rotating plate, a 45-degree polarizer, a 22.5-degree half-wave plate and a-22.5-degree half-wave plate which are arranged along the direction from the first polarization beam splitting assembly to the second polarization beam splitting assembly, one end surface of the 45-degree half-wave plate is attached to the end surface of the first 45-degree rhombic prism close to the polarization rotation mechanism, one end surface of the glass flat plate is attached to the right-angle surface of the first 45-degree right-angle prism close to the polarization rotation mechanism, the other end surface of the 45-degree half-wave plate and the other end surface of the glass flat plate are respectively attached to one end surface of the 90-degree polarizer, the other end surface of the 90-degree polarizer is attached to one end surface of the 45-degree rotating plate, the other end surface of the 45-degree rotating plate is attached to one end surface of the-45-degree polarizer, one end face of the-22.5-degree half-wave plate is attached to the end face, close to the polarization rotating mechanism, of the second 45-degree rhombic prism, and the other end face of the 22.5-degree half-wave plate and the other end face of the-22.5-degree half-wave plate are respectively attached to the other end face of the-45-degree polarizing plate.
As a second preferred implementation structure of the polarization rotation mechanism, the polarization rotation mechanism includes a first 45-degree half-wave plate, a first glass flat plate, a 90-degree polarizing plate, a first 45-degree rotating plate, -45-degree polarizing plate, a second 45-degree rotating plate, a 0-degree polarizing plate, a second 45-degree half-wave plate and a second glass flat plate which are arranged along the direction from the first polarization beam splitting assembly to the second polarization beam splitting assembly; the 90-degree polaroid, the first 45-degree rotating sheet, the-45-degree polaroid, the second 45-degree rotating sheet and the 0-degree polaroid are sequentially attached, one end face of the first 45-degree half-wave plate is attached to the end face, close to the polarization rotating mechanism, of the first 45-degree rhombic prism, one end surface of the first glass flat plate is attached to a right-angle surface of the first 45-degree right-angle prism, which is close to the polarization rotating mechanism, the other end surface of the first 45-degree half-wave plate and the other end surface of the first glass flat plate are respectively attached to an end surface of the 90-degree polarizing plate, which is close to the first polarization light splitting assembly, one end surface of the second 45-degree half-wave plate is attached to the right-angle surface of the second 45-degree right-angle prism close to the polarization rotating mechanism, one end face of the second glass flat plate is attached to the end face, close to the polarization rotating mechanism, of the second 45-degree rhombic prism, and the other end face of the second 45-degree half-wave plate and the other end face of the second glass flat plate are respectively attached to the end face, close to the second polarization light splitting assembly, of the 0-degree polarizing plate.
As a third preferred implementation structure of the polarization rotation mechanism, the polarization rotation mechanism includes a first 45-degree half-wave plate, a first glass flat plate, a first 45-degree rotating plate, a-45-degree polarizing plate, a second 45-degree rotating plate, a second 45-degree half-wave plate and a second glass flat plate which are arranged along the direction from the first polarization light splitting assembly to the second polarization light splitting assembly; the first 45-degree rotating sheet, the 45-degree polaroid and the second 45-degree rotating sheet are sequentially attached, one end face of the first 45-degree half-wave plate is attached to the end face, close to the polarization rotating mechanism, of the first 45-degree rhombic prism, one end surface of the first glass flat plate is attached to a right-angle surface of the first 45-degree right-angle prism, which is close to the polarization rotating mechanism, the other end surface of the first 45-degree half-wave plate and the other end surface of the first glass flat plate are respectively attached to an end surface of the first 45-degree rotating plate, which is close to the first polarization light splitting assembly, one end surface of the second 45-degree half-wave plate is attached to the right-angle surface of the second 45-degree right-angle prism close to the polarization rotating mechanism, one end face of the second glass flat plate is attached to the end face, close to the polarization rotating mechanism, of the second 45-degree rhombic prism, and the other end face of the second 45-degree half-wave plate and the other end face of the second glass flat plate are respectively attached to the end face, close to the second polarization light splitting assembly, of the second 45-degree rotating plate.
Furthermore, wedge angle pieces are arranged on the end faces, far away from the polarization rotating mechanism, of the first 45-degree oblique square prism and the second 45-degree oblique square prism.
Furthermore, the first polarization light splitting assembly, the polarization rotating mechanism and the second polarization light splitting assembly are fixed into a whole by gluing, optical cement or deepening optical cement in sequence.
An optical isolator comprising the polarization independent small integrated free space isolator described above.
An optical system comprising the optical isolator described above.
By adopting the technical scheme, compared with the prior art, the invention has the beneficial effects that: the scheme of the invention aims at the limitation problems of poor isolation effect or very large insertion loss caused by unpolarized light when the polarization state of input signal light is random or unpolarized light in the existing isolator, and provides an isolator scheme which can be suitable for polarized light or unpolarized light as light signal input, namely a polarization-independent free space isolator, namely, the differential loss of the isolator can be very low no matter whether the incident light is polarized or not, and the performance index of the isolation degree can not be influenced; in addition, the scheme of the invention also has the advantages of small volume, integrated structure, easy processing and mass production, low cost, high reliability and the like.
Drawings
The invention will be further explained with reference to the drawings and the detailed description below:
FIG. 1 is a schematic diagram of one embodiment of a single stage isolator of the prior art;
FIG. 2 is a schematic diagram of an embodiment of a dual stage isolator in the prior art;
FIG. 3 is a schematic view of embodiment 1 of the isolator of the present invention, in which the propagation path of the forward optical path is shown;
FIG. 4 is a schematic view of embodiment 1 of the isolator of the present invention, in which the propagation path of the reverse optical path is shown;
FIG. 5 is a schematic view showing another connection structure of embodiment 1 of the separator of the present invention;
FIG. 6 is a schematic view of embodiment 2 of the isolator of the present invention, in which the propagation path of the forward optical path is shown;
FIG. 7 is a schematic view of embodiment 2 of the isolator of the present invention, in which the propagation path of the reverse optical path is shown;
FIG. 8 is a schematic view showing another connection structure of embodiment 2 of the separator of the present invention;
FIG. 9 is a schematic view of embodiment 3 of the isolator of the present invention, in which the propagation path of the forward optical path is shown;
FIG. 10 is a schematic view of embodiment 3 of the isolator of the present invention, in which the propagation path of the reverse optical path is shown;
FIG. 11 is a schematic view showing another connection structure of embodiment 3 of the separator of the present invention;
fig. 12 is a schematic view of embodiment 4 of the separator of the present invention.
Detailed Description
For convenience of describing the transmission of the optical path, the specific implementation of the scheme of the present invention is defined as follows: the polarization direction of the S light is determined as an X axis from left to right in the drawing, the polarization direction of the P light is positioned on a Y axis, the angle is an included angle with the X axis, the anticlockwise rotation angle relative to the X axis is positive, and the clockwise rotation angle is negative.
Example 1
As shown in one of fig. 3 to 5, the isolator of the present embodiment includes a first polarization beam splitting component 1, a polarization rotation mechanism, and a second polarization beam splitting component 9 sequentially arranged along the optical path direction;
the first polarization light splitting component 1 comprises a first 45-degree oblique square prism 11 and a first 45-degree right-angle prism 12, wherein the upper end surface of the first 45-degree oblique square prism 11 can be selectively plated with a high-reflection film or a non-plated film, and the lower end surface of the first 45-degree oblique square prism is plated with a polarization light splitting film 13 and is attached and fixed with the inclined surface of the first 45-degree right-angle prism 12 into a whole;
the second polarization beam splitting assembly 9 comprises a second 45-degree oblique square prism 91 and a second 45-degree right-angle prism 92, wherein a high-reflection film is plated on the upper end surface or the lower end surface of the second 45-degree oblique square prism 91, and when the high-reflection film is plated on the upper end surface or the high-reflection film is not plated on the upper end surface, a polarization beam splitting film 93 is plated on the lower end surface and is attached and fixed with the inclined surface of the second 45-degree right-angle prism 92 into a whole; when the lower end surface is plated with a high-reflection film or no film, the upper end surface is plated with a polarization beam splitting film 93 and is attached and fixed with the inclined surface of the second 45-degree right-angle prism into a whole (i.e., as shown in the present embodiment).
The polarization rotation mechanism described in this embodiment includes a 45-degree half-wave plate 2, a glass plate 3, a 90-degree polarizer 4, a 45-degree rotator 5, a-45-degree polarizer 6, a 22.5-degree half-wave plate 7, and a-22.5-degree half-wave plate 8 disposed along the direction from the first polarization beam splitting assembly 1 to the second polarization beam splitting assembly 9, one end surface of the 45-degree half-wave plate 2 is attached to the end surface of the first 45-degree rhombic prism 11 close to the polarization rotation mechanism, one end surface of the glass plate 3 is attached to the right-angle surface of the first 45-degree right-angle prism 12 close to the polarization rotation mechanism, the other end surfaces of the 45-degree half-wave plate 2 and the glass plate 3 are respectively attached to one end surface of the 90-degree polarizer 4, the other end surface of the 90-degree polarizer 4 is attached to one end surface of the 45-degree rotator 5, the other end surface of the 45-degree rotator 5 is attached to one, one end face of the 22.5-degree half-wave plate 7 is attached to the right-angle face, close to the polarization rotating mechanism, of the second 45-degree right-angle prism 92, one end face of the-22.5-degree half-wave plate 8 is attached to the end face, close to the polarization rotating mechanism, of the second 45-degree oblique prism 91, and the other end face of the 22.5-degree half-wave plate 7 and the other end face of the-22.5-degree half-wave plate 8 are respectively attached to the other end face of the-45-degree polarizing plate 7.
The structure of the embodiment is a single-stage polarization independent free space isolator, and the single-stage polarization independent free space isolator can be respectively connected with a first polarization light splitting component 1 and a second polarization light splitting component 9 through an optical cement or glue bonding method on the incident end face and the emergent end face of a traditional single-stage free space isolator; if the glue is used for connection, the glue comprises one or more of UV glue, thermal curing glue, dual curing glue and the like; in order to reduce the Insertion Loss (IL), a method of plating an antireflection film on glue can be adopted to eliminate the IL according to the difference of the refractive indexes of the materials, and if the refractive index of the cured glue is close to that of the material of the optical spacing sheet, the antireflection film does not need to be plated.
Fig. 3 shows the propagation path of the forward optical path of the structure of the present embodiment; the incident end signal is unpolarized light (usually a laser, or a single-mode fiber and a corresponding collimator) and is separated into S light and P light after passing through the polarization splitting film 13 of the first polarization splitting assembly 1, wherein: for the S light, after the S light passes through the polarization splitting film 13, the S light is reflected upwards and turns 90 degrees, then a 45-degree reflecting surface with a high reflection film or without a film is plated on the upper end surface of the first 45-degree oblique prism 11, the reflection is usually internal total reflection, the reflected light is transmitted to the polarization rotating mechanism direction and enters the 45-degree half-wave plate 2, and then the polarization direction of the S light is rotated 90 degrees and changed into P light; for the P light, after passing through the polarization splitting film 13, the P light is completely transmitted and then enters the glass flat plate 3, and is still the P light before entering the 90-degree polarizing plate 4. At this time, after the unpolarized light passes through the light splitting assembly, the upper and lower optical paths are all converted into a single P-polarized light, and then the P-polarized light sequentially enters the 90 ° polarizer 4, the 45 ° rotator 5, and the-45 ° polarizer 6, and since the direction of the polarized light is parallel to the transmission direction of the 90 ° polarizer 4, the loss of the polarized light is very low. After passing through a-45-degree polarizing film 6, the polarization direction of light forms-45 degrees with the X axis; for the upper light path, the incident light passes through the 22.5-degree half-wave plate 7, the polarization state is converted into P light, then the P light enters the second polarization light splitting component 9, passes through the polarization light splitting film 93, directly penetrates through the second polarization light splitting component and is emitted from the emergent end; for the lower light path, the incident light passes through a-22.5-degree half-wave plate 8, the polarization state is converted into S light, the S light passes through a 45-degree reflecting surface on the lower end surface of the second 45-degree rhombic prism 91, the reflection is internal total reflection (or a high-reflection film can be optionally coated on the reflecting surface), the reflected light turns upwards to 90 degrees, and after being transmitted through the polarization beam splitting film 93, the light is reflected by the polarization beam splitting film 93 and turns to the right to 90 degrees, and is emitted from an emitting end; at this time, the S light and the P light are recombined into a beam of light, and forward beam combination and conduction are further realized.
As shown in fig. 4, which shows the propagation path of the reverse optical path of the present embodiment; the backward transmission light is also unpolarized light, and according to the reversibility of the light path, before the backward transmission light passes through the 45 ° rotation plate 5, the polarization state of the backward light is consistent with that of the forward light, and there is no isolation effect at this time, but after passing through the 45 ° rotation plate 5, the polarization state of the backward light will be rotated by 90 ° relative to the forward light, which is orthogonal to the optical axis direction 41 of the 90 ° polarization plate 4, that is, the polarization light at this time will be completely absorbed by the 90 ° polarization plate 4, and the function of backward isolation is realized.
In this example, an anti-reflection film may be coated on all the bonded surfaces or deepened optical adhesive surfaces through which the optical path passes, or no anti-reflection film may be coated on all the bonded surfaces or deepened optical adhesive surfaces, but the interface refractive index is matched with the glue refractive index or an optical adhesive dielectric film is coated on all the bonded surfaces or deepened optical adhesive surfaces, and the anti-reflection film is coated on both the incident and exit ports, so that very low insertion loss can be achieved.
Fig. 5 shows a modified structure of the present example, which can ensure that the incident light and the outgoing light are on the same line, i.e., the coaxiality. The embodiment can also realize the light path structure with the incident end and the emergent end vertical to each other by changing the positions of the half-wave plate and the glass plate. The specific working principle is similar to the foregoing, and is not described herein again.
Example 2
As shown in one of fig. 6 to 8, the present embodiment is substantially the same as embodiment 1, except that the polarization rotation mechanism includes a first 45-degree half-wave plate 2, a first glass plate 3, a 90-degree polarizer 4, a first 45-degree rotator 5, a-45-degree polarizer 6, a second 45-degree rotator 7, a 0-degree polarizer 8, a second 45-degree half-wave plate 9, and a second glass plate 10 disposed along the direction from the first polarization splitting assembly 1 to the second polarization splitting assembly 110; the 90-degree polarizer 4, the first 45-degree rotating plate 5, the-45-degree polarizer 6, the second 45-degree rotating plate 7 and the 0-degree polarizer 8 are sequentially attached, one end face of the first 45-degree half-wave plate 2 is attached to the end face, close to the polarization rotating mechanism, of the first 45-degree oblique prism 11, one end face of the first glass flat plate 3 is attached to the right-angle face, close to the polarization rotating mechanism, of the first 45-degree right-angle prism 12, the other end face of the first 45-degree half-wave plate 2 and the other end face of the first glass flat plate 3 are respectively attached to the end face, close to the first polarization light splitting assembly 1, of the 90-degree polarizer 4, one end face of the second 45-degree half-wave plate 9 is attached to the face, close to the polarization rotating mechanism, of the second 45-degree right-angle prism 1102, one end face of the second glass flat plate 10 is attached to the end face, close to the polarization rotating mechanism, and the other end faces of the second 45-degree half-wave plate 9 and the second glass The end face 8 close to the second polarization beam splitting assembly 11 is attached.
In the embodiment, the first polarization beam splitting component 1 and the second polarization beam splitting component 110 are respectively connected to the incident end face and the emergent end face of the traditional double-stage free space optical isolator by using an optical cement or glue bonding method; if the glue is used for connection, the glue comprises one or more of UV glue, thermal curing glue, dual curing glue and the like; in order to reduce the Insertion Loss (IL), a method of plating an antireflection film on glue can be adopted to eliminate the IL according to the difference of the refractive indexes of the materials, and if the refractive index of the cured glue is close to that of the material of the optical spacing sheet, the antireflection film does not need to be plated.
In this embodiment, the present embodiment is a dual-stage polarization independent free space isolator, fig. 6 shows a schematic propagation of a forward optical signal in this embodiment, an incident end signal is unpolarized light (generally, a laser, or a single-mode fiber and a corresponding collimator) and is separated into S light and P light after passing through a polarization splitting film 13 of a first polarization splitting assembly 1, where: for the S light, after passing through the polarization splitting film 13, the light is reflected upward and turned to 90 °, and then passes through a 45 ° reflection surface on the upper end surface of the first 45 ° rhombic prism 11, where the reflection is usually total internal reflection (or a high reflection film may be optionally coated on the surface), the reflection light is transmitted to the right and enters the first 45 ° half-wave plate 2, and the polarization direction of the S light is turned to 90 ° to become P light; for the P light, after passing through the polarization splitting film 13, the light is completely transmitted and then enters the first glass plate 3, and is still the P light before entering the 90-degree polarizing plate 4. At this time, after the unpolarized light passes through the first polarization beam splitter 1, the upper and lower optical paths are all converted into a single P-polarized light, and then the P-polarized light sequentially enters the 90 ° polarizer 4, the first 45 ° rotator 5, the-45 ° polarizer 6, the second 45 ° rotator 7, and the 0 ° polarizer 8, and since the direction of the polarized light is parallel to the transmission direction of the 90 ° polarizer 4, the loss of the polarized light is low. After passing through the 0-degree polarizing film 8, the polarization state of the light is S light; for the upper light path, the light enters through the second 45 ° half-wave plate 9, the polarization state is converted into P light, and then the P light passes through the polarization splitting film 1103 of the second polarization splitting assembly 110, directly penetrates through and is emitted from the exit end; for the lower light path, the light enters through the second flat glass sheet 10, the polarization state is still S light, and passes through the 45 ° reflection surface on the lower end surface of the second 45 ° rhombic prism 1101, where the reflection is usually total internal reflection (or a high reflection film may be optionally coated on the surface), the reflection light turns upward to 90 °, after passing through the polarization splitting film 1101, the light is reflected by the polarization splitting film 1101 and turns rightward to 90 °, and is emitted from the emission end; at this time, the S light and the P light are recombined into a beam of light, and forward beam combination and conduction are further realized.
Fig. 7 shows the reverse transmission light path of the present embodiment, the reverse transmission light is also unpolarized light, and according to the reversibility of the light path, before the reverse transmission light passes through the 45 ° rotation plate (the first 45 ° rotation plate 5 and the second 45 ° rotation plate 7), the polarization state of the reverse light path is consistent with that of the forward light path, at this time, there is no isolation effect, but after passing through the 45 ° rotation plate, the polarization state of the reverse light will rotate 90 ° with respect to the forward light, which is orthogonal to the optical axis direction of the polarizer to be incident, that is, the polarization light at this time will be completely absorbed by the polarizer, thereby achieving the function of reverse isolation. Because the invention has two 45-degree rotating sheets and the polaroids with the mutual included angle of 45 degrees in sequence, the light transmitted in reverse direction can be isolated and absorbed twice, and the isolation degree higher than that of a single-stage isolator can be realized, and can usually reach more than 55 dB.
Fig. 8 is a schematic diagram of a modified structure of the present example, which can ensure that the incident light and the emergent light are on the same line, i.e., coaxiality. The embodiment can also realize the light path structure with the incident end and the emergent end vertical to each other by changing the positions of the half-wave plate and the glass plate. The specific working principle is similar to the foregoing, and is not described herein again.
In this example, an anti-reflection film may be coated on all the bonded surfaces or deepened optical adhesive surfaces through which the optical path passes, or no anti-reflection film may be coated on all the bonded surfaces or deepened optical adhesive surfaces, but the interface refractive index is matched with the glue refractive index or an optical adhesive dielectric film is coated on all the bonded surfaces or deepened optical adhesive surfaces, and the anti-reflection film is coated on both the incident and exit ports, so that very low insertion loss can be achieved.
Example 3
As shown in one of fig. 9 to 11, the present embodiment is substantially the same as embodiment 1, except that the polarization rotation mechanism includes a first 45-degree half-wave plate 2, a first glass plate 3, a first 45-degree rotating plate 4, a-45-degree polarizing plate 5, a second 45-degree rotating plate 6, a second 45-degree half-wave plate 7 and a second glass plate 8 arranged along the direction from the first polarization beam splitting assembly 1 to the second polarization beam splitting assembly 9; the first 45-degree rotating plate 4, the-45-degree polarizing plate 5 and the second 45-degree rotating plate 6 are sequentially attached, one end face of the first 45-degree half-wave plate 2 is attached to the end face, close to the polarization rotating mechanism, of the first 45-degree oblique prism 11, one end face of the first glass flat plate 3 is attached to the right-angle face, close to the polarization rotating mechanism, of the first 45-degree right-angle prism 12, the other end face of the first 45-degree half-wave plate 2 and the other end face of the first glass flat plate 3 are respectively attached to the end face, close to the first polarization light-splitting assembly 1, of the first 45-degree rotating plate 4, one end face of the second 45-degree half-wave plate 7 and the right-angle face, close to the polarization rotating mechanism, of the second 45-degree oblique prism 91, of the one end face of the second glass flat plate 8, the other end face of the second 45-degree half-wave plate 7 and the other end face of the second glass flat plate 8 are respectively attached to the right-angle face, close to the second polarization light-splitting The end faces of the pieces 9 abut.
This embodiment is through the polaroid replacement with traditional doublestage free space optical isolator incident end and exit end for first polarization beam splitting component 1 and second polarization beam splitting component 9, not only can realize the function that the polarization is irrelevant, because the existence of two 45 degrees rotatorys pieces and middle polaroids, can also realize the performance of doublestage isolator. Compared with the structure in the embodiment 2, the structure has the advantages of less materials and higher cost performance. In the structure, a first polarization light splitting component 1, a first 45-degree rotating sheet 4, a-45-degree polarizing sheet 5, a second 45-degree rotating sheet 6 and a second polarization light splitting component 9 are respectively connected by a light glue or glue bonding method; if the glue is used for connection, the glue comprises one or more of UV glue, thermal curing glue, dual curing glue and the like; in order to reduce the Insertion Loss (IL), a method of plating an antireflection film on glue can be adopted to eliminate the IL according to the difference of the refractive indexes of the materials, and if the refractive index of the cured glue is close to that of the material of the optical spacing sheet, the antireflection film does not need to be plated.
In this embodiment, the present embodiment is a dual-stage polarization independent free space isolator, fig. 9 shows a forward optical signal propagation schematic of this embodiment, and an incident end signal is unpolarized light (generally, a laser, or a single-mode fiber and a corresponding collimator) and is separated into S light and P light after passing through the polarization splitting film 13 of the first polarization splitting assembly 1, where: for the S light, after passing through the polarization splitting film 13, the light is reflected upward and turned to 90 °, and then passes through a 45 ° reflection surface on the upper end surface of the first 45 ° rhombic prism 11, where the reflection is usually total internal reflection (or a high reflection film may be optionally coated on the surface), the reflection light is transmitted to the right and enters the first 45 ° half-wave plate 2, and the polarization direction of the S light is turned to 90 ° to become P light; for the P light, after passing through the polarization splitting film 13, the light is completely transmitted and then enters the first glass plate 3, and is still the P light before entering the first 45 ° rotation plate 4. At this time, after unpolarized light passes through the first polarization beam splitter assembly 1, the upper and lower optical paths are all converted into single P-polarized light, and then the single P-polarized light sequentially enters the first 45-degree rotating plate 4, the-45-degree polarizing plate 5 and the second 45-degree rotating plate 6, and since the direction of the polarized light is parallel to the transmission direction of the-45-degree polarizing plate 5, the loss of the polarized light is very low. After passing through the second 45-degree rotating sheet 6, the polarization state of the light is S light; for the upper light path, the light enters through the second 45-degree half-wave plate 7, the polarization state is converted into P light, and then the P light passes through the polarization beam splitting film 93 of the second polarization beam splitting assembly 9, directly penetrates through the polarization beam splitting film and is emitted from the emitting end; for the lower light path, the light enters through the glass flat plate, the polarization state is still S light, the S light passes through the 45 ° reflecting surface of the second 45 ° rhombic prism 91, the reflection here is usually total internal reflection (or a high reflection film can be optionally coated on the surface), the reflected light turns upward to 90 °, after being transmitted through the polarization beam splitting film 93, the light is reflected by the polarization beam splitting film 93 and turns to the right to 90 °, and is emitted from the emitting end; at this time, the S light and the P light are recombined into a beam of light, and forward beam combination and conduction are further realized.
Fig. 10 shows the backward transmission light path of the present embodiment, the backward transmission light is also unpolarized light, and according to the reversibility of the light path, before the backward transmission light passes through the second 45 ° rotation plate 6, the polarization state of the backward light is consistent with the forward light path, and there is no isolation effect at this time, but after passing through the second 45 ° rotation plate 6, the polarization state of the backward light will rotate 90 ° with respect to the forward light, which is orthogonal to the optical axis direction of the-45 ° polarizer 5, that is, the polarization light at this time will be almost completely absorbed by the-45 ° polarizer 5, so as to realize the backward isolation function. If there is residual very weak reverse transmission light, considering that the extinction ratio of the-45-degree polarizer 5 can reach more than 50dB, the polarization direction of the weak reflection light is parallel to the optical axis of the-45-degree polarizer 5, and the polarization state is changed into S light after the reverse transmission passes through the first 45-degree rotating plate 4; for the upper S light, after passing through the first 45 ° half-wave plate 2, it becomes P light, which passes through the 45 ° reflection surface on the upper end surface of the first rhombic prism 11, where the reflection is total internal reflection (or a high reflection film may be optionally coated), the reflection light turns downward to 90 °, after passing through the polarization splitting film 13, the reflection light passes through the polarization splitting film 13, and the light beam exits from the port perpendicular to the incident surface (i.e. the other right-angle surface of the first 45 ° right-angle prism 12); for the lower S light, after passing through the glass flat sheet, the S light is still S light, and after passing through the polarization splitting film 13 of the first polarization splitting assembly 1, the light is reflected by the polarization splitting film 13 and turns downward by 90 °, and the light beam is emitted from the port perpendicular to the incident end; thus, a dual stage isolation function for reverse transmitted light is achieved. The present structure also achieves much higher isolation than a single stage isolator, typically up to over 50 dB.
Fig. 11 is a modified structure of the present example, which can ensure that incident light and outgoing light are on the same line, i.e., coaxiality. The embodiment can also realize the light path structure with the incident end and the emergent end vertical to each other by changing the positions of the half-wave plate and the glass plate. The specific working principle is similar to the foregoing, and is not described herein again.
In this example, an anti-reflection film may be coated on all the bonded surfaces or deepened optical adhesive surfaces through which the optical path passes, or no anti-reflection film may be coated on all the bonded surfaces or deepened optical adhesive surfaces, but the interface refractive index is matched with the glue refractive index or an optical adhesive dielectric film is coated on all the bonded surfaces or deepened optical adhesive surfaces, and the anti-reflection film is coated on both the incident and exit ports, so that very low insertion loss can be achieved.
Example 4
Fig. 12 is a schematic structural diagram of an embodiment 4 of the present invention, which has a structure substantially the same as that of embodiment 1, and is different in that wedge pieces 10 are disposed on end surfaces of the first 45-degree rhombic prism 11 and the second 45-degree rhombic prism 91, which are far away from the polarization rotation mechanism.
In order to improve the Return Loss (RL) performance of the circulator, small-angle wedge sheets with the same angle can be respectively added to the incident port and the emergent port of the polarization-independent free space isolator through the processes of gluing or deepening optical cement or the optical cement, and the incident light beam and the emergent light beam are not 90 degrees from the end surface.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
In all the schemes mentioned in the invention, because the first polarization beam splitting assembly, the second polarization beam splitting assembly and various optical elements can be manufactured into long and very high angle precision slender strips in the same batch during processing, similarly, the 45-degree rotating plate and the half-wave plate can also be manufactured into long strips with optimal length, the slender strips are aligned without complex debugging and alignment, then the slender strips are assembled and integrated by adopting gluing or deepening optical cement or optical cement process, and finally the slender strips are cut into a plurality of finished products, which can greatly reduce the processing and assembling cost.
In addition, because the size of the integrated free space optical isolator can be very small, the size can reach 0.5mm or less, the material cost can be greatly reduced, and the requirement of a future small-sized good device on a micro optical element can be met.
Claims (10)
1. The utility model provides a polarization is irrelevant small-size integrates free space isolator which characterized in that: the polarization beam splitter comprises a first polarization beam splitting component, a polarization rotating mechanism and a second polarization beam splitting component which are sequentially arranged along the direction of a light path;
the first polarization light splitting assembly comprises a first 45-degree oblique square prism and a first 45-degree right-angle prism, wherein the upper end face of the first 45-degree oblique square prism is plated or not plated with a high-reflection film, and the lower end face of the first 45-degree oblique square prism is plated with a polarization light splitting film and is attached and fixed with the inclined plane of the first 45-degree right-angle prism into a whole;
the second polarization beam splitting assembly comprises a second 45-degree oblique prism and a second 45-degree right-angle prism, wherein a polarization beam splitting film is arranged on the upper end surface or the lower end surface of the second 45-degree oblique prism and is fixedly integrated with the inclined surface of the second 45-degree right-angle prism in an attaching mode, and a high reflection film is plated or not plated on the end surface, far away from the polarization beam splitting film, of the second polarization beam splitting assembly.
2. A polarization independent compact integrated free space isolator as claimed in claim 1, wherein: the polarization rotating mechanism comprises a 45-degree half-wave plate, a glass flat plate, a 90-degree polarizing plate, a 45-degree rotating plate, a-45-degree polarizing plate, a 22.5-degree half-wave plate and a-22.5-degree half-wave plate which are arranged along the direction from the first polarization light splitting assembly to the second polarization light splitting assembly, one end surface of the 45-degree half-wave plate is attached to the end surface, close to the polarization rotating mechanism, of the first 45-degree oblique prism, one end surface of the glass flat plate is attached to the right-angle surface, close to the polarization rotating mechanism, of the first 45-degree right-angle prism, the other end surface of the 45-degree half-wave plate and the other end surface of the glass flat plate are respectively attached to one end surface of the 90-degree polarizing plate, the other end surface of the 90-degree polarizing plate is attached to one end surface of the 45-degree rotating plate, the other end surface of the 45-degree rotating plate is attached to one end surface of the, one end face of the-22.5-degree half-wave plate is attached to the end face, close to the polarization rotating mechanism, of the second 45-degree rhombic prism, and the other end face of the 22.5-degree half-wave plate and the other end face of the-22.5-degree half-wave plate are respectively attached to the other end face of the-45-degree polarizing plate.
3. A polarization independent compact integrated free space isolator as claimed in claim 1, wherein: the polarization rotating mechanism comprises a first 45-degree half-wave plate, a first glass plain plate, a 90-degree polarizing plate, a first 45-degree rotating plate, a-45-degree polarizing plate, a second 45-degree rotating plate, a 0-degree polarizing plate, a second 45-degree half-wave plate and a second glass plain plate which are arranged along the direction from the first polarization light splitting assembly to the second polarization light splitting assembly; the 90-degree polaroid, the first 45-degree rotating sheet, the-45-degree polaroid, the second 45-degree rotating sheet and the 0-degree polaroid are sequentially attached, one end face of the first 45-degree half-wave plate is attached to the end face, close to the polarization rotating mechanism, of the first 45-degree rhombic prism, one end surface of the first glass flat plate is attached to a right-angle surface of the first 45-degree right-angle prism, which is close to the polarization rotating mechanism, the other end surface of the first 45-degree half-wave plate and the other end surface of the first glass flat plate are respectively attached to an end surface of the 90-degree polarizing plate, which is close to the first polarization light splitting assembly, one end surface of the second 45-degree half-wave plate is attached to the right-angle surface of the second 45-degree right-angle prism close to the polarization rotating mechanism, one end face of the second glass flat plate is attached to the end face, close to the polarization rotating mechanism, of the second 45-degree rhombic prism, and the other end face of the second 45-degree half-wave plate and the other end face of the second glass flat plate are respectively attached to the end face, close to the second polarization light splitting assembly, of the 0-degree polarizing plate.
4. A polarization independent compact integrated free space isolator as claimed in claim 1, wherein: the polarization rotating mechanism comprises a first 45-degree half-wave plate, a first glass plain plate, a first 45-degree rotating plate, a-45-degree polarizing plate, a second 45-degree rotating plate, a second 45-degree half-wave plate and a second glass plain plate which are arranged along the direction from the first polarization light splitting assembly to the second polarization light splitting assembly; the first 45-degree rotating sheet, the 45-degree polaroid and the second 45-degree rotating sheet are sequentially attached, one end face of the first 45-degree half-wave plate is attached to the end face, close to the polarization rotating mechanism, of the first 45-degree rhombic prism, one end surface of the first glass flat plate is attached to a right-angle surface of the first 45-degree right-angle prism, which is close to the polarization rotating mechanism, the other end surface of the first 45-degree half-wave plate and the other end surface of the first glass flat plate are respectively attached to an end surface of the first 45-degree rotating plate, which is close to the first polarization light splitting assembly, one end surface of the second 45-degree half-wave plate is attached to the right-angle surface of the second 45-degree right-angle prism close to the polarization rotating mechanism, one end face of the second glass flat plate is attached to the end face, close to the polarization rotating mechanism, of the second 45-degree rhombic prism, and the other end face of the second 45-degree half-wave plate and the other end face of the second glass flat plate are respectively attached to the end face, close to the second polarization light splitting assembly, of the second 45-degree rotating plate.
5. A polarization independent mini-integrated free space isolator as claimed in claim 2, 3 or 4, wherein: and wedge angle pieces are arranged on the end surfaces, far away from the polarization rotating mechanism, of the first 45-degree oblique square prism and the second 45-degree oblique square prism.
6. A polarization independent compact integrated free space isolator as claimed in claim 1, wherein: the first polarization light splitting assembly, the polarization rotating mechanism and the second polarization light splitting assembly are fixed into a whole by gluing, optical cement or deepening optical cement in sequence.
7. A polarization independent compact integrated free space isolator as claimed in claim 2, wherein: and the positions of the 45-degree half-wave plate and the glass flat plate of the polarization rotating mechanism are exchanged.
8. A polarization independent compact integrated free space isolator as claimed in claim 3 or 4, wherein: and the positions of the first 45-degree half-wave plate and the first glass flat plate of the polarization rotating mechanism are exchanged.
9. An optical isolator, comprising: comprising a polarization independent compact integrated free space isolator as claimed in any one of claims 1 to 4.
10. An optical system, characterized by: comprising the optical isolator of claim 7.
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| CN201910188534.4A CN111694100A (en) | 2019-03-13 | 2019-03-13 | Polarization-independent small-sized integrated free space isolator |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112799185A (en) * | 2021-04-14 | 2021-05-14 | 武汉恩达通科技有限公司 | Four-port circulator for single-fiber bidirectional communication and optical module |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05188324A (en) * | 1992-01-14 | 1993-07-30 | Namiki Precision Jewel Co Ltd | Polarized wave-no dependence type optical isolator array |
| JPH07281129A (en) * | 1994-04-06 | 1995-10-27 | Fuji Elelctrochem Co Ltd | Optical isolator for high power |
| JPH07301734A (en) * | 1994-03-07 | 1995-11-14 | Fujitsu Ltd | Optical coupler |
| CN1393713A (en) * | 2001-06-25 | 2003-01-29 | Jds尤尼费斯公司 | Optical splitter |
| CN103869418A (en) * | 2014-03-04 | 2014-06-18 | 青岛海泰光电技术有限公司 | Broadband-spectrum high-damage-threshold optical isolator |
| US20160047987A1 (en) * | 2014-08-13 | 2016-02-18 | Finisar Corporation | Optical circulators integrated into transceivers |
| CN108153002A (en) * | 2016-12-05 | 2018-06-12 | 信越化学工业株式会社 | polarization independent type optical isolator |
| CN109407355A (en) * | 2018-12-28 | 2019-03-01 | 光越科技(深圳)有限公司 | Double-stage photo-insulator |
-
2019
- 2019-03-13 CN CN201910188534.4A patent/CN111694100A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05188324A (en) * | 1992-01-14 | 1993-07-30 | Namiki Precision Jewel Co Ltd | Polarized wave-no dependence type optical isolator array |
| JPH07301734A (en) * | 1994-03-07 | 1995-11-14 | Fujitsu Ltd | Optical coupler |
| JPH07281129A (en) * | 1994-04-06 | 1995-10-27 | Fuji Elelctrochem Co Ltd | Optical isolator for high power |
| CN1393713A (en) * | 2001-06-25 | 2003-01-29 | Jds尤尼费斯公司 | Optical splitter |
| CN103869418A (en) * | 2014-03-04 | 2014-06-18 | 青岛海泰光电技术有限公司 | Broadband-spectrum high-damage-threshold optical isolator |
| US20160047987A1 (en) * | 2014-08-13 | 2016-02-18 | Finisar Corporation | Optical circulators integrated into transceivers |
| CN108153002A (en) * | 2016-12-05 | 2018-06-12 | 信越化学工业株式会社 | polarization independent type optical isolator |
| CN109407355A (en) * | 2018-12-28 | 2019-03-01 | 光越科技(深圳)有限公司 | Double-stage photo-insulator |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112799185A (en) * | 2021-04-14 | 2021-05-14 | 武汉恩达通科技有限公司 | Four-port circulator for single-fiber bidirectional communication and optical module |
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