Miniaturized optical path wave combining module with isolator function

Abstract

The utility model discloses a miniaturizable optical path wave combining module with an isolator function, which comprises a polarization light splitting element, an optical path wave combining module and an optical path wave combining module, and is characterized in that the polarization light splitting element is provided with a light splitting interface; each optical isolation unit comprises a polaroid, a phase delay element, a reflection optical element and a Faraday optical rotation sheet which are arranged along an incident light path; and the third phase delay element and the third reflection optical element are arranged along a reflection light path of the light splitting interface. The optical path wave combining module is wide in application range, has the function of an optical isolator, and can be miniaturized.

Description

Technical Field

[0001] The utility model relates to the technical field of optical communications, in particular to a miniaturized optical path combining module with an isolator function. Background Art

[0002] Optical combiners are used to combine optical signals from different optical paths into one optical signal and output it. Currently, the most widely used high-speed optical communication optical combiners are of the following three types: (1) Z-block-based optical combiners, which are obtained by butterfly packaging or box packaging of Z-blocks. These optical combiners have the disadvantages of high cost, complex process, and difficulty in miniaturization; (2) Arrayed waveguide grating (AWG)-based optical combiners, which have strict requirements on wavelength selection, high insertion loss, and are also difficult to miniaturize; (3) Filter-based optical combiners, which are large in size and also difficult to miniaturize. Utility Model Content

[0003] The purpose of the utility model is to provide a miniaturized optical path combining module with an isolator function. The optical path combining module has a wide range of applications, has an optical isolator function, and can be miniaturized.

[0004] The utility model 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 are arranged on both sides of the polarization beam splitter element. 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 phase delay element and the reflective optical element are used to modulate the incident polarized light; the reflective optical elements in the two optical isolation units are used to guide the respective incident polarized lights to opposite sides of the beam splitting interface;

[0007] A third phase delay element and a third reflective optical element are arranged along a reflective optical path of the beam splitting interface. The third reflective optical element is used to reflect the reflected polarized light from the beam splitting interface back to the beam splitting interface. The third phase delay element is used to modulate the incident reflected polarized light.

[0008] In some specific embodiments, the polarization beam splitting element is a PBS prism.

[0009] In some specific embodiments, the two optical isolation units are symmetrically arranged on both 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 half-wave plate, and the optical rotation angle of the Faraday rotator is configured to be 45°.

[0013] In some 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-reflection mirror or a high-reflection 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 laminated and arranged along the second direction, wherein the reflective optical element and Faraday rotator in one optical isolation unit are laminated and arranged along the first direction, and the reflective optical element and Faraday rotator in the other optical isolation unit are laminated and arranged in the opposite direction of the first direction; and the Faraday rotators in the two optical isolation units are respectively laminated 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°.

[0017] In some specific embodiments, 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 to fit 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 pairwise 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] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] 1. This utility model can realize the one-way passage of optical signals and reverse cutoff, and has the function of optical isolator;

[0022] 2. The utility model has a wide applicable wavelength range and can be used within the effective working wavelength range of the polarization beam splitter and the Faraday rotator.

[0023] 3. By adjusting the optical path, this utility model can achieve reverse or near-reverse light output, meaning that the direction of the incident light and the outgoing light are opposite or nearly opposite. Compared to existing optical combiner devices that output light in the forward direction, reverse or near-reverse light output facilitates optical path folding, enabling miniaturization of the optical combiner module. In the provided embodiment, the optical combiner module can be dimensioned to 2.5mm by 1.3mm, meeting the requirements of conventional TO-CAN packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a structural diagram of the optical path combining module in an embodiment of the present utility model;

[0026] Figure 2 for Figure 1 3D perspective view of the mid-path multiplexing module;

[0027] 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 utility model;

[0028] Figure 4 Schematic diagram of the optical transmission principle of the second optical isolation unit in an embodiment of the present utility model.

[0029] Figure 1: Polarization spectrometer 100, light exit surface 100a, spectrometer 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

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] Figures 3-4 The figure shows a schematic diagram of the optical path combining module of the embodiment of the present invention from a top view angle. Figures 3-4 Mark the XY rectangular coordinate system, and record the positive and negative directions of the X axis as "right" and "left" respectively, and the positive and negative directions of the Y axis as "back" and "front" respectively. 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 utility model are described in detail.

[0032] 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 optionally be a ceramic base.

[0033] The polarization beam splitter 100 has a beam splitting interface 110 that reflects polarized S light and transmits polarized P light. The beam splitting interface 110 is tilted relative to both the X-axis and the Y-axis. In this embodiment, the angles between the beam splitting interface 110 and the positive directions of both the X-axis and the Y-axis are 45°. A light exit surface 100a is provided at the front end of the polarization beam splitter 100, and the combined light is output from the light exit surface 100a. A PBS prism can be used as the polarization beam splitter 100.

[0034] The two optical isolation units are designated as a first optical isolation unit and a second optical isolation unit, and are disposed on either side of the polarization beam splitter element. In an embodiment of the present invention, the first optical isolation unit and the second optical isolation unit are symmetrically disposed on either side of the polarization beam splitter element 100. The first optical isolation unit and the second optical isolation unit receive first and second incident polarized light, respectively, modulate the first and second incident polarized light, and direct the modulated polarized light toward the first and second surfaces of the beam splitter interface 110, respectively. In a specific embodiment, the polarization state of the modulated incident polarized light is S-polarized light, which reaches the beam splitter interface 110 as S-polarized light and is reflected.

[0035] In this embodiment, both the first incident polarized light and the second incident polarized light arrive at the beam splitter interface 110 as S-polarized light and are reflected by the first and second surfaces of the beam splitter interface 110, respectively, forming two reflected light paths. A third phase delay element 400 and a third reflecting optical element 500 are sequentially arranged on one of the reflected light paths. Specifically, the third phase delay element 400 and the third reflecting optical element 500 are sequentially arranged on the reflected light path of the second surface of the beam splitter interface 110. The reflected polarized light reflected from the second surface passes through the third phase delay element 400, the third reflecting optical element 500, and the third phase delay element 400 in sequence, and then returns to the second surface of the beam splitter interface 110. During this process, the third phase delay element 400 rotates the polarization plane of the reflected polarized light twice, converting it into P-polarized light. The reflected polarized light then returns to the second surface of the beam splitter interface 110 as P-polarized light and passes through the beam splitter interface 110. The third phase retarder 400 has an optical rotation angle configured to rotate the polarization plane of the reflected polarized light twice, converting the reflected polarized light into polarized P light. Specifically, the third phase retarder 400 may be a quarter-wave plate. The third reflective optical element 500 may be a highly reflective mirror or film, configured to deflect the direction of travel of the reflected polarized light by 180°.

[0036] In the present invention, the first optical isolation unit and the second optical isolation unit primarily serve to transmit and isolate incident polarized light. In this embodiment, the first optical isolation unit includes a first polarizer 210, a first phase retarder 220, a first reflective optical element 230, and a first Faraday rotator 240, arranged along the first incident optical 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 direct the first incident polarized light toward the first surface of the beam splitting interface 110. The first phase retarder 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 retarder 220 and the first Faraday rotator 240 are configured such that the first incident polarized light reaches the beam splitting interface 110 as S-polarized light, and the backward-transmitted light is perpendicular to the polarization direction of the first polarizer 210 upon reaching the first polarizer 210. Backward-propagating light is a beam of light generated in the optical path that propagates in the opposite direction and can adversely affect light sources. In the present invention, the backward-propagating light that reaches the first polarizer 210 is perpendicular to the polarization direction of the first polarizer 210 and cannot be transmitted through the first polarizer 210, thereby achieving optical path isolation.

[0037] The second optical isolation unit has the same structure as the first optical 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 optical isolation unit are the same as those of the first optical isolation unit and are not further described here.

[0038] In a magnetic field, the first Faraday rotator 240 and the second Faraday rotator 340 can rotate the polarization plane of polarized light. In this embodiment, magnets are used to generate the magnetic field. For example, a magnetic block can be disposed at the top of each of the first Faraday rotator 240 and the second Faraday rotator 340. Alternatively, a magnetic block 250 can be disposed at the top of each of the first Faraday rotator 240 and the second Faraday rotator 340, spanning the first Faraday rotator 240 and the second Faraday rotator 340.

[0039] 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°, so that the deflected incident polarized light is incident on two opposite sides of the light splitting interface 110. The first reflective optical element 230 and the second reflective optical element 330 can be specifically selected from reflective prisms.

[0040] In the first and second optical isolation units, first incident polarized light enters from the first light input surface 210a at the front end of the first polarizer 210, and second incident polarized light enters from the second light input surface 310a of the second polarizer 310. The first and second phase delay elements 220 and 320 are used to rotate the polarization plane of the incident polarized light. The first and second reflective optical elements 230 and 330 are used to change the direction of travel of the polarized light by reflection. The first and second Faraday rotators 240 and 340 are used to rotate the polarization plane of the incident polarized light again, converting the polarized light into S-polarized light, which then reaches both sides of the beam splitting interface 110.

[0041] In this embodiment, a possible specific layout of the optical path combining module is as follows:

[0042] 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 a first direction; the first polarizer 210, the first phase retarder 220, and the first reflective optical element 230 are sequentially laminated and arranged along a second direction; and the second polarizer 310, the second phase retarder 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 and second directions are the positive directions of the X and Y axes, and the angle between them is 90°. Selecting an angle of 90° facilitates manufacturing and reduces size.

[0043] When the first reflective optical element 230 and the second reflective optical element 330 are reflective prisms, the first Faraday rotator 240 and the first phase retarder 220 are respectively arranged to mate with two right-angled surfaces of the first reflective optical element 230, and the second Faraday rotator 340 and the second phase retarder 320 are respectively arranged to mate with two right-angled surfaces of the second reflective optical element 330.

[0044] The working principle of the optical path combining module of the present invention will be provided below in conjunction with embodiments.

[0045] In this embodiment, the first phase delay element 220 and the second phase delay element 320 are half-wave plates for rotating the polarization plane of polarized light 45° counterclockwise. The first Faraday rotator 240 and the second Faraday rotator 340 have a rotation angle of 45° for rotating the polarization plane of polarized light 45° counterclockwise. The first reflective optical element 230 and the second reflective optical element 330 are reflective prisms.

[0046] The first incident polarized light, denoted as λ1, 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, travels along the positive Y-axis, and reaches the first phase retarder 220. The first phase retarder 220 rotates the polarization plane of the polarized light by 45° counterclockwise. After passing through the first reflective optical element 230, the polarized light's direction of travel is reversed to the negative X-axis. The first Faraday rotator 240 rotates the polarization plane of the polarized light by another 45° counterclockwise, converting the horizontally polarized P light into horizontally polarized S light. The horizontally polarized S light is incident from the right side of the polarization splitter element 100 onto the first surface of the beam splitter interface 110. After reflection from the beam splitter interface 110, it is output from the light exit surface 100a at the front end of the polarization splitter element 100, producing the first exit light. The first exit light is horizontally polarized S light with a polarization direction opposite to that of the incident polarized light λ1.

[0047] The second incident polarized light, denoted as λ2, 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, travels along the positive Y-axis, and reaches the second phase retarder 320. The second phase retarder 320 rotates the polarization plane of the polarized light 45° counterclockwise. After passing through the second reflective optical element 330, the polarized light changes its direction of travel to the positive X-axis. The second Faraday rotator 340 rotates the polarization plane of the polarized light by another 45° counterclockwise, converting the horizontally polarized P light into horizontally polarized S light. Horizontally polarized S light is incident on the second surface of the beam splitting interface 110 from the left side of the polarization beam splitter 100, reflected by the beam splitter interface 110, and travels in the positive direction along the Y axis to the third phase delay element 400. The third phase delay element 400 converts the circularly polarized light into circularly polarized light. The third reflective optical element 500 is used to deflect the traveling direction of the circularly polarized light by 180°. The light then returns to the third phase delay element 400, whereupon the circularly polarized light is converted into linearly polarized P light. The light is incident on the second surface of the beam splitting interface 110 from the rear end of the polarization beam splitter 100, 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 second exit light. The second exit light is horizontally polarized P light in the opposite direction to the incident polarized light λ2.

[0048] When external reflected light enters, backward propagation light is generated. The polarization state of the backward propagation 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 beam splitting interface 110 and enters the first optical isolation unit in the reverse direction. The first Faraday rotator 240 rotates the reverse polarized S light counterclockwise by 45°. The first reflective optical element 230 guides the light to the first phase delay element 220, which rotates the light clockwise by 45°, offsetting the rotation of the first Faraday rotator 240. The reverse polarized S light then reaches the first polarizer 210 in its original state. At this point, the polarized S light is perpendicular to the polarization direction of the first polarizer 210, thereby achieving optical isolation.

[0049] 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 back to the second surface of the splitter interface 110. It is reflected by the second surface of the splitter interface 110 and enters the second optical isolation unit in the opposite direction. The second optical isolation unit implements optical isolation on it. The principle is the same as that of the first optical isolation unit and will not be repeated here.

[0050] 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 .

[0051] 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.

[0052] In the above-mentioned embodiments, the optical path design was redesigned using a polarization beam splitter, a phase delay element (e.g., a half-wave plate or a quarter-wave plate), a reflective optical element, and a Faraday rotator, achieving reverse light output, where the incident polarization and the outgoing polarization are opposite. While existing optical combiner devices mostly output light in the forward direction, reverse light output allows for optical path folding, providing a foundation for significantly reducing the size of optical combiner modules and chips, enabling miniaturization of optical combiner modules.

[0053] The size of the optical path combining module in the above embodiment can be controlled to 2.5mm*1.3mm, which is fully applicable to conventional TO-CAN packaging.

[0054] Note that the above are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are readily apparent to those skilled in the art without departing from the scope of protection of the present invention. Therefore, while the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of protection of the present invention.

Claims

1. A miniaturized optical path combining module with isolator function, characterized by: include: a polarization beam splitting element having a beam splitting interface; Two optical isolation units are arranged on both sides of the polarization beam splitting element, 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 phase delay element and the reflective optical element are used to modulate the incident polarized light; the reflective optical elements in the two optical isolation units are used to guide the respective incident polarized lights to the two sides of the beam splitting interface relative to each other; A third phase delay element and a third reflective optical element are arranged along a reflective optical path of the beam splitting interface. The third reflective optical element is used to reflect the reflected polarized light from the beam splitting interface back to the beam splitting interface. The third phase delay element is used to modulate the incident reflected polarized light.

2. The miniaturized optical path combining module with isolator function according to claim 1, characterized in that: The polarization beam splitting element is a PBS prism.

3. The miniaturized optical path combining module with isolator function according to claim 1, characterized in that: The two optical isolation units are symmetrically arranged on both sides of the polarization beam splitting element.

4. The miniaturized optical multiplexing module with isolator function according to claim 1, wherein: 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 according to claim 1, wherein: The reflective optical elements in the two light isolation units are reflective prisms.

6. The miniaturized optical multiplexing module with isolator function according to claim 1, wherein: 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 according to claim 1, characterized in that: The polarization angle of the third reflective optical element is 180°.

8. The miniaturized optical multiplexing module with isolator function according to claim 1, wherein: The third reflective optical element is a high reflective mirror or a high reflective film.

9. The miniaturized optical multiplexing module with isolator function according to claim 1, wherein: The third phase delay element is a quarter wave plate.

10. The miniaturized optical path combining module with isolator function according to claim 1, characterized in that: The polarizer, phase delay element, and reflective optical element in each optical isolation unit are sequentially laminated and arranged along the second direction. The reflective optical element and Faraday rotator in one optical isolation unit are laminated and arranged along the first direction, while the reflective optical element and Faraday rotator in the other optical isolation unit are laminated and arranged in the opposite direction to the first direction. The Faraday rotators in the two optical isolation units are respectively laminated and arranged on both sides of the polarization beam splitting element. The angle between the first direction and the second direction is 80° to 100°.

11. The miniaturized optical path combining module with isolator function according to 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-angled surfaces of the reflective optical element.

12. The miniaturized optical multiplexing module with isolator function according to claim 1, wherein: The device further 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 multiplexing module with isolator function according to claim 12, characterized in that: The base is a ceramic base.

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