Miniaturized optical path wave combining module with isolator function and application thereof
By using polarization spectroscopic optical spectroscopy elements, phase delay and optical rotary sheets in the optical path combination module, the reverse output and isolation of optical signals are achieved, and the problem of difficulty in miniaturization of existing optical path combination devices is solved, and the application of widely used and the reduction of module size.
Patent Information
- Application Number
- CN202411649822.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-01-07
AI Technical Summary
Existing optical-path combined devices are difficult to miniaturize, and have high costs, complex processes, and have strict requirements on wavelength selection, making them difficult to apply widely.
A miniaturizable optical path combined module with isolator function is designed, using polarized spectroscopic optical component, two optical isolation unit and third phase retardation element to realize the reverse or Close to the reverse output, combined with the ceramic base, the module is miniaturized.
It realizes unidirectional passage and optical isolation of optical signals, has a wide wavelength range, and the module size can be controlled to be 2.5mm*1.3mm, which is suitable for conventional TO-CAN packages, realizing the miniaturization of optical combined wave modules.
Smart Images
Figure CN119270537A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical communication technology, and in particular to a miniaturized optical path combining module with an isolator function and its application. Background Art
[0002] Optical combiner devices are used to combine optical signals in different optical paths into one optical signal and output it. Currently, there are three types of optical combiner devices for high-speed optical communication that are widely used: (1) Optical combiner devices based on Z-blocks, which are obtained by butterfly packaging or box packaging of Z-blocks. This type of optical combiner device has the disadvantages of high cost, complex process, and difficulty in miniaturization; (2) Optical combiner devices based on arrayed waveguide gratings (AWGs), which have strict requirements on wavelength selection, large insertion loss, and are also difficult to miniaturize; (3) Optical combiner devices based on filters, which are large in size and also difficult to miniaturize. Summary of the invention
[0003] The purpose of the present application is to provide a miniaturized optical path combining module with an isolator function and its application. The optical path combining module has a wide range of applications, has an optical isolator function, and can be miniaturized.
[0004] On the one hand, the present application provides a miniaturized optical path combining module with an isolator function, comprising:
[0005] A polarization beam splitting element having a beam splitting interface;
[0006] Two optical isolation units, each optical isolation unit includes: a polarizer, a phase delay element, a reflective optical element, and a Faraday rotator arranged along the incident light path; the incident polarized light is converted into polarized S light after passing through the phase delay element and the Faraday rotator, and the backward transmitted light is orthogonal to the polarization direction of the polarizer after passing through the Faraday rotator and the phase delay element; the reflective optical elements in the two optical isolation units are used to relatively guide the respective incident polarized lights to the two sides of the splitting interface;
[0007] A third phase delay element and a third reflective optical element are arranged along a reflective optical path of the splitter interface. The third reflective optical element is used to reflect the reflected polarized light from the splitter interface back to the splitter interface. The third phase delay element is used to adjust the polarization direction of the reflected polarized light passing through so that the reflected polarized light reaches the splitter interface in the state of polarized P light.
[0008] In some specific embodiments, the polarization beam splitting element is a PBS prism.
[0009] In some specific embodiments, two optical isolation units are arranged on two sides of the polarization beam splitting element.
[0010] In some specific embodiments, the deflection angle of the reflective optical elements in the two light isolation units is 80° to 100°.
[0011] In some specific embodiments, the reflective optical elements in the two light isolation units are reflective prisms.
[0012] In some specific embodiments, the phase delay element is a 1 / 2 wave plate, and the optical rotation angle of the Faraday rotator is configured to be 45°.
[0013] In some specific embodiments, the polarization angle of the third reflective optical element is 180°.
[0014] In some specific embodiments, the third reflective optical element is a high reflective mirror or a high reflective film.
[0015] In some specific embodiments, the third phase delay element is a quarter wave plate.
[0016] In some specific embodiments, the polarizer, phase delay element, and reflective optical element in each optical isolation unit are sequentially bonded and arranged along the second direction, wherein the reflective optical element and the Faraday rotator in one optical isolation unit are bonded and arranged along the first direction, and the reflective optical element and the Faraday rotator in the other optical isolation unit are bonded and arranged in the opposite direction of the first direction; and the Faraday rotators in the two optical isolation units are respectively bonded and arranged on both sides of the polarization splitting element; and the angle between the first direction and the second direction is 80° to 100°.
[0017] In some specific implementations, the reflective optical element is a reflective prism, and the phase delay element and the Faraday rotator in each optical isolation unit are respectively arranged in contact with two right-angled surfaces of the reflective optical element.
[0018] In some specific embodiments, the miniaturized optical path combining module further includes a base, and the polarization beam splitting element, the two-by-two optical isolation units, the third phase delay element, and the third reflective optical element are all disposed on the base.
[0019] Furthermore, the base is a ceramic base.
[0020] On the other hand, the present application also provides the application of the above-mentioned miniaturized optical path combining module in polarization multiplexing optical communication transmission.
[0021] Compared with the prior art, this application has the following advantages and beneficial effects:
[0022] 1. This application can realize the one-way passage of optical signals and reverse cutoff, and has the function of optical isolator;
[0023] 2. The present application has a wide applicable wavelength range and can be used within the effective working wavelength range of polarization beam splitters and Faraday rotators.
[0024] 3. This application can achieve reverse or nearly reverse light emission through optical path adjustment, that is, the direction of incident light is opposite or nearly opposite to that of outgoing light; compared with the current optical path combiner device with forward light emission, reverse or nearly reverse light emission is conducive to optical path folding, so that the miniaturization of the optical path combiner module can be realized. In the provided embodiment, the size of the optical path combiner module can be controlled to 2.5mm*1.3mm, which can meet the requirements of conventional TO-CAN packaging. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0026] Figure 1 This is a schematic diagram of the structure of the optical path combining module in the embodiment of the present application;
[0027] Figure 2 for Figure 1 3D perspective view of the mid-path multiplexing module;
[0028] Figure 3 This is a schematic diagram of the optical path transmission principle of the first optical isolation unit in an embodiment of the present application;
[0029] Figure 4 Schematic diagram of the optical path transmission principle of the second optical isolation unit in the embodiment of the present application.
[0030] Figure numerals: polarization splitter element 100, light output surface 100a, splitter interface 110; first polarizer 210, first light input surface 210a, first phase delay element 220, first reflective optical element 230, first Faraday rotator 240, magnetic block 250; second polarizer 310, second light input surface 310a, second phase delay element 320, second reflective optical element 330, second Faraday rotator 340; third phase delay element 400, third reflective optical element 500, base 600. DETAILED DESCRIPTION
[0031] The following will be combined with the implementation methods of this application to clearly and completely describe the technical solutions in the implementation methods of this application. Obviously, the described implementation methods are only part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0032] Figures 3-4 FIG. 1 is a schematic diagram of a top view of an optical path combining module according to an embodiment of the present application. Figures 3-4 In the figure, we mark the XY rectangular coordinate system, and the positive and negative directions of the X axis are marked as "right" and "left", and the positive and negative directions of the Y axis are marked as "back" and "front". Figures 1 to 4 The structure and working principle of the miniaturized optical path combining module with isolator function in the embodiment of the present application are described in detail.
[0033] The miniaturized optical path combining module of this embodiment includes a base 600, and a polarization splitting element 100, a first optical isolation unit, a second optical isolation unit, a third phase delay element 400 and a third reflective optical element 500 arranged on the base 600; the base 600 can be a ceramic base.
[0034] The polarization beam splitter element 100 has a beam splitter interface 110 that reflects polarized S light and transmits polarized P light. The beam splitter interface 110 is inclined relative to both the X-axis and the Y-axis. In this embodiment, the angles between the beam splitter interface 110 and the positive directions of the X-axis and the Y-axis are both 45°. A light emitting surface 100a is provided at the front end of the polarization beam splitter element 100, and the combined wave is output from the light emitting surface 100a. The polarization beam splitter element 100 can specifically be a PBS prism.
[0035] The two optical isolation units are respectively recorded as the first optical isolation unit and the second optical isolation unit, and are respectively arranged on both sides of the polarization beam splitter element. In the embodiment of the present application, the first optical isolation unit and the second optical isolation unit are symmetrically arranged on both sides of the polarization beam splitter element 100, and the first optical isolation unit and the second optical isolation unit respectively receive the first incident polarized light and the second incident polarized light, and the first incident polarized light and the second incident polarized light are relatively guided to the first surface and the second surface of the beam splitter interface 110. In the process of guiding the first incident polarized light and the second incident polarized light to the beam splitter interface 110, the two optical isolation units also convert the polarization state of the first incident polarized light and the second incident polarized light into polarized S light, and reach the beam splitter interface 110 in the state of polarized S light and are reflected.
[0036] In the present application, the first incident polarized light and the second incident polarized light both arrive at the beam splitting interface 110 in the state of polarized S light, and are respectively reflected by the first surface and the second surface of the beam splitting interface 110, forming two reflected light paths. The third phase delay element 400 and the third reflective optical element 500 are arranged in sequence on one of the reflected light paths. In this embodiment, the third phase delay element 400 and the third reflective optical element 500 are arranged in sequence on the reflected light path of the second surface of the beam splitting interface 110, and the reflected polarized light reflected by the second surface passes through the third phase delay element 400, the third reflective optical element 500, and the third phase delay element 400 in sequence, and returns to the second surface of the beam splitting interface 110 again. In this process, the third phase delay element 400 rotates the polarization plane of the reflected polarized light twice, converts the reflected polarized light into polarized P light, and the reflected polarized light returns to the second surface of the beam splitting interface 110 in the state of polarized P light, and passes through the beam splitting interface 110. The optical rotation angle of the third phase delay element 400 is configured such that after rotating the polarization plane of the reflected polarized light twice, the reflected polarized light is converted into polarized P light. The third phase delay element 400 may be a quarter wave plate. The third reflective optical element 500 may be a high reflective mirror or a high reflective film to deflect the traveling direction of the reflected polarized light by 180°.
[0037] In the present application, the first optical isolation unit and the second optical isolation unit mainly play the role of transmitting the incident polarized light and optical isolation. In this embodiment, the first optical isolation unit includes a first polarizer 210, a first phase delay element 220, a first reflective optical element 230, and a first Faraday rotator 240 arranged along the first incident light path L1; the first polarizer 210 has the same polarization direction as the first incident polarized light; the first reflective optical element 230 is used to guide the first incident polarized light to the first surface of the light splitting interface 110; the first phase delay element 220 and the first Faraday rotator 240 are used to rotate the polarization planes of the first incident polarized light and the backward transmitted light; the optical rotation angles of the first phase delay element 220 and the first Faraday rotator 240 are configured to: make the first incident polarized light reach the light splitting interface 110 in the state of polarized S light, and make the backward transmitted light perpendicular to the polarization direction of the first polarizer 210 when it reaches the first polarizer 210 in the reverse direction. The backward transmission light is a light beam that is generated in the optical path and is transmitted in the reverse direction, which may have an adverse effect on the light source, etc. In the present application, the backward transmission light that reaches the first polarizer 210 is perpendicular to the polarization direction of the first polarizer 210, and the backward transmission light cannot be transmitted from the first polarizer 210, thereby achieving optical path isolation.
[0038] The second light isolation unit has the same structure as the first light isolation unit, and includes a second polarizer 310, a second phase delay element 320, a second reflective optical element 330, and a second Faraday rotator 340 arranged along the second incident light path L2; the structure and principle of the second light isolation unit are the same as those of the first light isolation unit, and will not be repeated here.
[0039] In a magnetic field environment, the first Faraday rotator 240 and the second Faraday rotator 340 can rotate the polarization plane of polarized light. In this embodiment, a magnet is used to generate a magnetic field. For example, a magnetic block can be arranged at the top of each of the first Faraday rotator 240 and the second Faraday rotator 340, or a magnetic block 250 spanning the first Faraday rotator 240 and the second Faraday rotator 340 can be arranged at the top of the first Faraday rotator 240 and the second Faraday rotator 340.
[0040] In this embodiment, the first reflective optical element 230 and the second reflective optical element 330 are used to deflect the direction of the incident polarized light by 80° to 100°, and the deflected incident polarized light is incident on two sides of the light splitting interface 110. The first reflective optical element 230 and the second reflective optical element 330 can be reflective prisms.
[0041] In the first light isolation unit and the second light isolation unit, the first incident polarized light enters from the first light input surface 210a at the front end of the first polarizer 210, and the second incident polarized light enters from the second light input surface 310a of the second polarizer 310; the first phase delay element 220 and the second phase delay element 320 are used to rotate the polarization plane of the incident polarized light; the first reflecting optical element 230 and the second reflecting optical element 330 are used to change the traveling direction of the polarized light by reflection; the first Faraday rotator 240 and the second Faraday rotator 340 are used to rotate the polarization plane of the incident polarized light again, so that the polarized light is converted into polarized S light and reaches the two sides of the splitting interface 110.
[0042] In this embodiment, a possible specific layout of the optical path combining module is as follows:
[0043] The second reflective optical element 330, the second Faraday rotator 340, the polarization beam splitter 100, the first Faraday rotator 240, and the first reflective optical element 230 are sequentially laminated and arranged along the first direction; the first polarizer 210, the first phase delay element 220, and the first reflective optical element 230 are sequentially laminated and arranged along the second direction; the second polarizer 310, the second phase delay element 320, and the second reflective optical element 330 are sequentially laminated and arranged along the second direction; the angle between the first direction and the second direction is 80° to 100°. In this embodiment, the first direction and the second direction are the positive directions of the X and Y axes, and the angle between the two is 90°. Selecting an angle of 90° facilitates manufacturing and size reduction.
[0044] When the first reflective optical element 230 and the second reflective optical element 330 select reflective prisms, the first Faraday rotator 240 and the first phase delay element 220 are respectively arranged to fit the two right-angled surfaces of the first reflective optical element 230, and the second Faraday rotator 340 and the second phase delay element 320 are respectively arranged to fit the two right-angled surfaces of the second reflective optical element 330.
[0045] The working principle of the optical path combining module of the present application will be provided below in combination with embodiments.
[0046] In this embodiment, the first phase delay element 220 and the second phase delay element 320 are selected as 1 / 2 wave plates to rotate the polarization plane of polarized light 45° counterclockwise; the rotation angles of the first Faraday rotator 240 and the second Faraday rotator 340 are configured to be 45° to rotate the polarization plane of polarized light 45° counterclockwise; the first reflecting optical element 230 and the second reflecting optical element 330 are selected as reflecting prisms.
[0047] The first incident polarized light is recorded as λ1, which is horizontally polarized P light. The polarization direction of the first polarizer 210 is the same as that of the incident polarized light λ1. The incident polarized light λ1 is input from the first light input surface 210a at the front end of the first polarizer 210, and travels along the positive direction of the Y axis to reach the first phase delay element 220. The first phase delay element 220 rotates the polarization plane of the polarized light by 45° counterclockwise, and then passes through the first reflective optical element 230, and the traveling direction of the polarized light is changed to the opposite direction of the X axis. The first Faraday rotator 240 rotates the polarization plane of the polarized light by 45° counterclockwise again, and the horizontally polarized P light is converted into horizontally polarized S light. The horizontally polarized S light is incident on the first surface of the beam splitting interface 110 from the right side of the polarization beam splitting element 100, is reflected by the beam splitting interface 110, and is output from the light exit surface 100a at the front end of the polarization beam splitting element 100 to obtain the first exit light, which is the horizontally polarized S light with the opposite polarization direction to the incident polarized light λ1.
[0048] The second incident polarized light is recorded as λ2, which is horizontally polarized P light. The polarization direction of the second polarizer 310 is the same as that of the incident polarized light λ2. The incident polarized light λ2 is input from the second light input surface 310a at the front end of the second polarizer 310, and travels along the positive direction of the Y axis to reach the second phase delay element 320. The second phase delay element 320 rotates the polarization plane of the polarized light by 45° counterclockwise, and then passes through the second reflective optical element 330, and the traveling direction of the polarized light is changed to the positive direction of the X axis; the second Faraday rotator 340 rotates the polarization plane of the polarized light by 45° counterclockwise again, and the horizontally polarized P light is converted into horizontally polarized S light. The horizontally polarized S light is incident from the left side of the polarization beam splitter 100 to the second surface of the beam splitter interface 110, is reflected by the beam splitter interface 110, travels along the Y-axis in the positive direction to the third phase delay element 400, is converted into circularly polarized light by the third phase delay element 400, and the third reflective optical element 500 is used to deflect the traveling direction of the circularly polarized light by 180°, and returns to the third phase delay element 400 again. The circularly polarized light is converted into linearly polarized P light, and is incident from the rear end of the polarization beam splitter 100 to the second surface of the beam splitter interface 110, passes through the beam splitter interface 110, and is output from the light exit surface 100a at the front end of the polarization beam splitter 100 to obtain a second exit light, which is a horizontally polarized P light in the opposite direction to the incident polarized light λ2.
[0049] When external reflected light enters, backward transmission light is generated. The polarization state of the backward transmission light is random and can be decomposed into polarized S light and polarized P light. The polarized S light is reflected by the first surface of the splitting interface 110 and enters the first light isolation unit in the reverse direction. The first Faraday rotator 240 rotates the reverse polarized S light counterclockwise by 45°. The first reflecting optical element 230 guides the light to the first phase delay element 220. The first phase delay element 220 rotates the light clockwise by 45°, which is offset by the rotation of the first Faraday rotator 240. The reverse polarized S light reaches the first polarizer 210 in the initial state. At this time, the polarized S light is perpendicular to the polarization direction of the first polarizer 210, thereby achieving light isolation.
[0050] The polarized P light in the backward transmitted light passes through the first surface of the splitter interface 110 and enters the third phase delay element 400. The third phase delay element 400 converts it into polarized S light. The third reflective optical element 500 guides it to the second surface of the splitter interface 110 again, and it is reflected by the second surface of the splitter interface 110 and enters the second optical isolation unit in the reverse direction. The second optical isolation unit implements optical isolation on it. The principle is the same as that of the first optical isolation unit, which will not be repeated here.
[0051] The horizontally polarized S light reflected by the first surface of the beam splitting interface 110 and the horizontally polarized P light transmitted through the second surface of the beam splitting interface 110 are combined with each other and output from the light output surface 100 a of the polarization beam splitting element 100 .
[0052] In the above embodiment, horizontally polarized P light is input, and completely orthogonal horizontally polarized P light and horizontally polarized S light are output, which can be applied to polarization multiplexing optical communication transmission.
[0053] In the above embodiments, the optical path is redesigned by using polarization beam splitters, phase delay elements (such as 1 / 2 wave plates, 1 / 4 wave plates), reflective optical elements and Faraday rotators to achieve reverse light emission, that is, the direction of incident polarized light is opposite to that of outgoing polarized light. Most existing optical path combining devices emit light in the forward direction. Compared with the forward light emission, the reverse light emission can achieve optical path folding, which provides a basis for greatly reducing the size of optical path combining modules and optical path combining chips, etc., and enables the miniaturization of optical path combining modules.
[0054] The size of the optical path combining module in the above embodiment can be controlled to 2.5mm*1.3mm, which is completely applicable to conventional TO-CAN packaging.
[0055] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the concept of the present application, all of which belong to the protection scope of the present application.
Claims
1. A miniaturized optical path combining module with an isolator function, characterized in that: include: A polarization beam splitting element having a beam splitting interface; Two optical isolation units, each optical isolation unit includes: a polarizer, a phase delay element, a reflective optical element, and a Faraday rotator arranged along the incident light path; the incident polarized light is converted into polarized S light after passing through the phase delay element and the Faraday rotator, and the backward transmitted light is orthogonal to the polarization direction of the polarizer after passing through the Faraday rotator and the phase delay element; the reflective optical elements in the two optical isolation units are used to relatively guide the respective incident polarized lights to the two sides of the splitting interface; A third phase delay element and a third reflective optical element are arranged along a reflective optical path of the splitter interface. The third reflective optical element is used to reflect the reflected polarized light from the splitter interface back to the splitter interface. The third phase delay element is used to adjust the polarization direction of the reflected polarized light passing through so that the reflected polarized light reaches the splitter interface in the state of polarized P light.
2. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The polarization beam splitting element is a PBS prism.
3. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The two optical isolation units are arranged on two sides of the polarization beam splitting element.
4. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The deflection angle of the reflective optical elements in the two light isolation units is 80° to 100°.
5. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The reflective optical element in the two light isolation units is a reflective prism.
6. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The phase delay element is a 1 / 2 wave plate, and the optical rotation angle of the Faraday rotator is configured to be 45°.
7. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The polarization angle of the third reflecting optical element is 180°.
8. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The third reflective optical element is a high reflective mirror or a high reflective film.
9. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The third phase delay element is a quarter wave plate.
10. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The polarizer, phase delay element, and reflective optical element in each optical isolation unit are sequentially bonded and arranged along the second direction, wherein the reflective optical element and the Faraday rotator in one optical isolation unit are bonded and arranged along the first direction, and the reflective optical element and the Faraday rotator in the other optical isolation unit are bonded and arranged in the opposite direction of the first direction; and the Faraday rotators in the two optical isolation units are respectively bonded and arranged on both sides of the polarization beam splitting element; and the angle between the first direction and the second direction is 80° to 100°.
11. The miniaturized optical path combining module with isolator function as claimed in claim 10, characterized in that: The reflective optical element is a reflective prism, and the phase delay element and the Faraday rotator in each optical isolation unit are respectively arranged in contact with two right-angle surfaces of the reflective optical element.
12. The miniaturized optical path combining module with isolator function as claimed in claim 1, characterized in that: The invention also comprises a base, on which the polarization beam splitting element, the two-by-two light isolation units, the third phase delay element and the third reflective optical element are all arranged.
13. The miniaturized optical path combining module with isolator function as claimed in claim 12, characterized in that: The base is a ceramic base.
14. Application of the miniaturized optical path combining module with isolator function as claimed in any one of claims 1 to 13 in polarization multiplexing optical communication transmission.