Wavelength division multiplexing structure for multi-wavelength and narrow wavelength interval

Abstract

The invention relates to a wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals, which comprises a first mounting surface, a second mounting surface, a third mounting surface, a fourth mounting surface, a fifth mounting surface and a fifth mounting surface, and is characterized in that the first mounting surface is provided with a reflecting diaphragm I, a reflecting diaphragm II and an optical channel I, and the second mounting surface is provided with an optical filter I, an optical filter II and an optical channel II; a PBS prism, a third optical filter and a fourth optical filter are arranged on the third mounting face, a first passage is reserved between the PBS prism and the third optical filter, a second passage is reserved between the third optical filter and the fourth optical filter, a third reflecting diaphragm is arranged on the fourth mounting face, a third optical channel, a fourth optical channel and a fifth optical channel are arranged on the fifth mounting face, and a fourth reflecting diaphragm is arranged on the fifth mounting face. An optical rotation sheet is arranged in the third optical channel; the multi-wavelength narrow-wavelength combiner has the advantages that by analyzing the wavelength intervals, adjusting the placing sequence of the optical filters and additionally arranging the PBS prisms and the optical rotators, the purpose of combining multi-wavelength and narrow-wavelength intervals is achieved, meanwhile, the size cannot be greatly changed, and the efficiency of an optical system and the manufacturing efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of optical communication, and particularly to a wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals. Background Art

[0002] In modern optical communication systems and optical sensing technologies, with the continuous growth of data transmission requirements, the efficient utilization of optical fiber bandwidth has become crucial. Dense wavelength division multiplexing (DWDM) technology, as an effective means, can simultaneously transmit multiple optical signals of different wavelengths on a physical medium (such as a single-mode optical fiber), thereby significantly improving the transmission capacity.

[0003] For example, a multi-wavelength gas sensor is a device that uses the interaction between light of different wavelengths and specific gas molecules to detect and analyze gas components and concentrations. Through wavelength multiplexing, multiple optical signals of different wavelengths can be transmitted through a single optical fiber, greatly simplifying the physical structure of the system. Specific wavelengths can be easily added or removed to meet different detection requirements, improving the detection efficiency.

[0004] However, when implementing multi-wavelength multiplexing, the situation of narrow wavelength intervals may be encountered. For example, in a six-wavelength device (such as the above-mentioned gas sensor, or 50G PON, etc.), the multi-wavelength and narrow wavelength interval may be less than 40 nm, and usually includes:

[0005] Emission wavelengths of λ1 - λ3: 1631.4 nm, 1650.9 nm, and 1680.2 nm respectively;

[0006] Emission wavelengths of λ4 - λ6: 1566.2 nm, 1529.2 nm, and 1578.2 nm respectively;

[0007] Among the above wavelengths, the wavelength intervals in λ1 - λ3 are less than 40 nm, and the wavelength intervals in λ4 - λ6 are less than 40 nm. It is impossible to achieve multiplexing using a conventional 45° filter.

[0008] Traditional solutions usually use two 13.5° MUX structures to complete multi-wavelength multiplexing, which results in a large overall package volume and is difficult to achieve miniaturized design of the device. For example, in a compact environment where multiple functional modules need to be integrated, this large-volume design greatly limits its application range.

[0009] Another common alternative is to use a single 13.5° MUX. Although it can reduce the occupied volume to a certain extent, it will increase the number of reflections of the incident light in the tail section, making the optical path longer, and thus affecting the coupling efficiency of the system. This problem is particularly prominent in application scenarios with high-precision requirements, such as multi-wavelength detection in gas sensors, where strict requirements are imposed on signal strength and stability.

[0010] Based on this, this case is thus proposed. Summary of the Invention

[0011] The object of the present invention is to provide a wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals to achieve multiplexing of multiple wavelengths and narrow wavelength intervals. At the same time, the volume of the entire wavelength division multiplexing structure will not change significantly, and both the high optical system efficiency and manufacturing efficiency are relatively excellent.

[0012] In order to achieve the above object, the technical solution of the present invention is as follows:

[0013] A wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals includes a carrier. The carrier includes five mounting surfaces from the first to the fifth, and a hollow space is provided inside the carrier for the light path to pass through. A first reflection film, a second reflection film, and a first optical channel are provided on the first mounting surface. A first filter, a second filter, and a second optical channel are provided on the second mounting surface. A PBS prism, a third filter, and a fourth filter are provided on the third mounting surface, and a first aisle is reserved between the PBS prism and the third filter, and a second aisle is reserved between the third filter and the fourth filter. A third reflection film is provided on the fourth mounting surface. A third optical channel, a fourth optical channel, and a fifth optical channel are provided on the fifth mounting surface, and a rotator is provided in the third optical channel.

[0014] The PBS prism is used to transmit horizontally polarized light and reflect vertically polarized light; the rotator is used to rotate horizontally polarized light into vertically polarized light.

[0015] The horizontally polarized light incident from the first filter sequentially passes through the first filter and the PBS prism and then reaches the first optical channel and is output.

[0016] The horizontally polarized light incident from the second filter sequentially passes through the second filter and the third filter and then reaches the second reflection film. After being reflected by the second reflection film, it passes through the first aisle to reach the first filter. After being reflected by the first filter, it reaches the PBS prism. After being transmitted by the PBS prism, it reaches the first optical channel and is output.

[0017] The horizontally polarized light incident from the second optical channel passes through the fourth filter and then reaches the first reflection film. After being reflected by the first reflection film, it passes through the second aisle to reach the second filter. After being reflected by the second filter, it reaches the third filter. After being transmitted by the third filter, it reaches the second reflection film. After being reflected by the second reflection film, it passes through the first aisle to reach the first filter. After being reflected by the first filter, it reaches the PBS prism. After being transmitted by the PBS prism, it reaches the first optical channel and is output.

[0018] The horizontally polarized light incident from the third optical channel is rotated into vertically polarized light by the rotator and then reaches the third reflection film. After being reflected by the third reflection film, it reaches the PBS prism. After being reflected by the PBS prism, it reaches the first optical channel and is output.

[0019] The horizontally polarized light incident from optical channel four reaches filter three after being reflected by reflecting diaphragm three, reaches reflecting diaphragm two after being reflected by filter three, passes through aisle one after being reflected by reflecting diaphragm two, reaches filter one after being reflected by filter one, reaches the PBS prism after being reflected by filter one, and is transmitted through the PBS prism to optical channel one and output;

[0020] The horizontally polarized light incident from optical channel five reaches filter four after being reflected by reflecting diaphragm three, reaches reflecting diaphragm one after being reflected by filter four, passes through aisle two after being reflected by reflecting diaphragm one, reaches filter two after being reflected by filter two, reaches filter three after being reflected by filter two, is transmitted through filter three to reach reflecting diaphragm two, passes through aisle one after being reflected by reflecting diaphragm two, reaches filter one after being reflected by filter one, reaches the PBS prism after being reflected by filter one, and is transmitted through the PBS prism to optical channel one and output.

[0021] Furthermore, a filter five is installed at the optical channel two for transmitting one of the lights incident on the optical channel two.

[0022] Furthermore, the carrier includes a mother carrier and an embedded carrier. The first mounting surface and the second mounting surface are provided on the mother carrier, and a mounting groove is provided on the mother carrier for the embedded carrier to be embedded. The third mounting surface, the fourth mounting surface and the fifth mounting surface are provided on the embedded carrier.

[0023] Furthermore, the reflecting diaphragm three includes three mutually independent reflecting diaphragms, and the three reflecting diaphragms respectively correspond to filter three, filter four and filter five one by one.

[0024] Furthermore, filter one transmits the light with a wavelength of 1631.4 nm and reflects the light with other wavelengths;

[0025] Filter two transmits the light with a wavelength of 1650.9 nm and reflects the light with other wavelengths;

[0026] Filter three reflects the light with a wavelength of 1529.2 nm and transmits the light with other wavelengths;

[0027] Filter four reflects the light with a wavelength of 1578.2 nm and transmits the light with other wavelengths;

[0028] Filter five transmits the light with a wavelength of 1680.2 nm and reflects the light with other wavelengths.

[0029] Furthermore, the carrier is made of a metal bracket.

[0030] The advantages of the present invention are as follows

[0031] 1. By analyzing each wavelength interval, adjusting the placement order of the filters, and adding a PBS prism and a rotator, the purpose of multiplexing multiple wavelengths with narrow wavelength intervals is achieved. Meanwhile, the volume will not change significantly, and it has better applicability to the subsequent supporting packages, improving the optical system efficiency and manufacturing efficiency. It also has good applicability for the design of more wavelengths such as eight wavelengths and ten wavelengths in the future;

[0032] 2. Adopting the structure of an embedded carrier can double the applicable wavelengths. Meanwhile, various angles of the carrier can be conveniently adjusted to achieve the multiplexing function, ensuring that the structural volume will not change significantly. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. is a three-dimensional structure schematic diagram of the wavelength division multiplexing structure in the embodiment;

[0034] Figure 2 is Figure 1 a three-dimensional structure schematic diagram from another perspective;

[0035] Figure 3 is Figure 1 an internal perspective schematic diagram of;

[0036] Figure 4 FIG. is a schematic diagram of the route of the λ1-λ3 emission wavelengths in the wavelength division multiplexing structure in the embodiment;

[0037] Figure 5 FIG. is a schematic diagram of the route of the λ4-λ6 emission wavelengths in the wavelength division multiplexing structure in the embodiment;

[0038] Figure 6 FIG. is a schematic diagram of the route of the λ1-λ6 emission wavelengths in the wavelength division multiplexing structure in the embodiment;

[0039] LABEL DESCRIPTION

[0040] In Figure 4 In Figure 5 In Figure 6 □ represents horizontally polarized light, and ○ represents vertically polarized light;

[0041] 1. First mounting surface; 2. Second mounting surface; 3. Third mounting surface; 4. Fourth mounting surface; 5. Fifth mounting surface; 6. First reflecting film; 7. Second reflecting film; 8. Third reflecting film; 9. First aisle; 10. Second aisle; 11. First filter; 12. Second filter; 13. Third filter; 14. Fourth filter; 15. Fifth filter; 16. PBS prism; 17. Rotator; 18. First optical channel; 19. Mother carrier; 20. Embedded carrier. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] The present invention will be further described in detail below in conjunction with embodiments. It should be understood that the orientation or positional relationships indicated by terms such as "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. in the text are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0043] As Figures 1 to 3 shown, this embodiment proposes a wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals, including a carrier. The carrier includes a mother carrier 19 and an embedded carrier 20. A first mounting surface 1 and a second mounting surface 2 are provided on the mother carrier 19, and a mounting groove is provided on the mother carrier 19 for the embedded carrier 20 to be embedded. A third mounting surface 3, a fourth mounting surface 4, and a fifth mounting surface 5 are provided on the embedded carrier 20. By using the embedded carrier 20, the application wavelength can be doubled, and various angles of the carrier can be adjusted. While realizing the multiplexing function, it is ensured that the structure volume will not change too much. In addition, a hollow space needs to be opened in the carrier for the light path to pass through.

[0044] The first mounting surface 11 and the second mounting surface 2 are arranged in the front-rear direction, and the embedded carrier 2018 is located between the first mounting surface 11 and the second mounting surface 2. The third mounting surface 3 is located below the fourth mounting surface 4 and the fifth mounting surface 5. Among them, a first reflection film 6, a second reflection film 7, and a first optical channel 18 are provided on the first mounting surface 1. A first filter 11, a second filter 12, and a second optical channel are provided on the second mounting surface 2. A PBS prism 16, a third filter 13, and a fourth filter 14 are provided on the third mounting surface 3. A first aisle 9 is reserved between the PBS prism 16 and the third filter 13, and a second aisle 10 is reserved between the third filter 13 and the fourth filter 14. A third reflection film 8 is provided on the fourth mounting surface 4. An optical channel three, an optical channel four, and an optical channel five are provided on the fifth mounting surface 5, and a rotatory polarizer 17 is provided in the optical channel three.

[0045] The PBS prism 16 is used to transmit horizontally polarized light and reflect vertically polarized light; the rotatory polarizer 17 is used to rotate horizontally polarized light into vertically polarized light.

[0046] This solution is used to solve the situation where a 45° filter cannot be used for multiplexing for six wavelengths and narrow wavelength intervals. Six wavelengths and narrow wavelength intervals usually include the following wavelengths:

[0047] λ1 - λ3 emission wavelengths: 1631.4 nm (λ1), 1650.9 nm (λ2), 1680.2 nm (λ3) respectively;

[0048] The emission wavelengths of λ4 - λ6 are 1566.2 nm (λ4), 1529.2 nm (λ5), and 1578.2 nm (λ6) respectively;

[0049] Among the above wavelengths, the wavelength intervals of λ1 - λ3 are less than 40 mm, and the wavelength intervals of λ4 - λ6 are less than 40 mm.

[0050] In addition, it should be noted that most of the optical paths on the market are in horizontal polarization state. During actual operation, a laser emitting horizontal polarized light can also be selected so that the emitted optical paths are all in horizontal polarization state, that is, the emission wavelengths of λ1 - λ6 are all horizontal polarized light.

[0051] The first filter 11 transmits light with a wavelength of 1631.4 nm and reflects light with other wavelengths.

[0052] The second filter 12 transmits light with a wavelength of 1650.9 nm and reflects light with other wavelengths.

[0053] The third filter 13 reflects light with a wavelength of 1529.2 nm and transmits light with other wavelengths.

[0054] The fourth filter 14 reflects light with a wavelength of 1578.2 nm and transmits light with other wavelengths.

[0055] Next, with reference to Figure 4 and Figure 6 , the route directions of the emission wavelengths of λ1 - λ3 in this wavelength division multiplexing structure will be described.

[0056] The working optical path principle of λ1: The horizontally polarized light incident from the first filter 11 sequentially passes through the first filter 11 and the PBS prism 16 and then reaches the first optical channel 18 and is output.

[0057] The working optical path principle of λ2: The horizontally polarized light incident from the second filter 12 sequentially passes through the second filter 12 and the third filter 13 and then reaches the second reflecting film 7. After being reflected by the second reflecting film 7, it passes through the first aisle 9 to reach the first filter 11. After being reflected by the first filter 11, it reaches the PBS prism 16. After being transmitted by the PBS prism 16, it reaches the first optical channel 18 and is output.

[0058] The working optical path principle of λ3: The horizontally polarized light incident from the second optical channel passes through the fourth filter 14 and then reaches the first reflecting film 6. After being reflected by the first reflecting film 6, it passes through the second aisle 10 to reach the second filter 12. After being reflected by the second filter 12, it reaches the third filter 13. After being transmitted by the third filter 13, it reaches the second reflecting film 7. After being reflected by the second reflecting film 7, it passes through the first aisle 9 to reach the first filter 11. After being reflected by the first filter 11, it reaches the PBS prism 16. After being transmitted by the PBS prism 16, it reaches the first optical channel 18 and is output.

[0059] Ideally, only λ3 enters the second optical channel. However, inevitably, some stray light will also enter the second optical channel, interfering with λ3 and even the light of other wavelengths within the wavelength division multiplexing structure. Preferably, in this embodiment, a fifth filter 15 is installed at the second optical channel. The fifth filter 15 transmits light with a wavelength of 1680.2 nm and reflects light of the remaining wavelengths. In this way, the stray light incident on the second optical channel cannot be transmitted, and only the light with a wavelength of 1680.2 nm (λ3) can enter.

[0060] Hereinafter, with reference to Figure 5 and Figure 6 , the routing of the emission wavelengths λ4 - λ6 in this wavelength division multiplexing structure will be described.

[0061] Working optical path principle of λ4: The horizontally polarized light incident from the third optical channel is rotated into vertically polarized light by the optical rotation sheet 17 and then reaches the third reflection film 8. After being reflected by the third reflection film 8, it reaches the PBS prism 16. After being reflected by the PBS prism 16, it reaches the first optical channel 18 and is output.

[0062] Working optical path principle of λ5: The horizontally polarized light incident from the fourth optical channel is reflected by the third reflection film 8 and then reaches the third filter 13. After being reflected by the third filter 13, it reaches the second reflection film 7. After being reflected by the second reflection film 7, it passes through the first aisle 9 and reaches the first filter 11. After being reflected by the first filter 11, it reaches the PBS prism 16. After being transmitted by the PBS prism 16, it reaches the first optical channel 18 and is output.

[0063] Working optical path principle of λ6: The horizontally polarized light incident from the fifth optical channel is reflected by the third reflection film 8 and then reaches the fourth filter 14. After being reflected by the fourth filter 14, it reaches the first reflection film 6. After being reflected by the first reflection film 6, it passes through the second aisle 10 and reaches the second filter 12. After being reflected by the second filter 12, it reaches the third filter 13. After being transmitted by the third filter 13, it reaches the second reflection film 7. After being reflected by the second reflection film 7, it passes through the first aisle 9 and reaches the first filter 11. After being reflected by the first filter 11, it reaches the PBS prism 16. After being transmitted by the PBS prism 16, it reaches the first optical channel 18 and is output.

[0064] Generally, the third reflection film 8 is a single integral piece. However, on the right side of the third reflection film 8, there are 3 corresponding optical channels, and below it, there are a PBS prism 16 and 2 filters. When installing and matching, it is not convenient to flexibly adjust the angle of a single integral film. Preferably, in this embodiment, the third reflection film 8 includes three mutually independent reflection films, so that the three reflection films can correspond to the third filter 13, the fourth filter 14, and the fifth filter 15 respectively, facilitating the matching adjustment of the installation angle.

[0065] In addition, the carrier in this embodiment adopts the form of a metal bracket to replace the existing glass block design structure, reducing costs and improving production efficiency.

[0066] The above embodiments are only used to explain the concept of the present invention, rather than limiting the protection scope of the present invention. Any non-substantive modifications made to the present invention using this concept shall fall within the protection scope of the present invention.

Claims

1. A wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals, comprising a carrier, characterized in that, The carrier includes five mounting surfaces from the first to the fifth, and a hollow space is provided inside the carrier for the light path to pass through; a first reflecting diaphragm, a second reflecting diaphragm and a first optical channel are provided on the first mounting surface, a first filter, a second filter and a second optical channel are provided on the second mounting surface, a PBS prism, a third filter and a fourth filter are provided on the third mounting surface, and a first aisle is reserved between the PBS prism and the third filter, and a second aisle is reserved between the third filter and the fourth filter. A third reflecting diaphragm is provided on the fourth mounting surface, and a third optical channel, a fourth optical channel and a fifth optical channel are provided on the fifth mounting surface, and a rotator is provided in the third optical channel; The PBS prism is used to transmit horizontally polarized light and reflect vertically polarized light; the rotator is used to rotate horizontally polarized light into vertically polarized light; The horizontally polarized light incident from the first filter passes through the first filter and the PBS prism in sequence and then reaches the first optical channel and is output; The horizontally polarized light incident from the second filter passes through the second filter and the third filter in sequence and then reaches the second reflecting diaphragm. After being reflected by the second reflecting diaphragm, it passes through the first aisle to reach the first filter, is reflected by the first filter and then reaches the PBS prism, is transmitted by the PBS prism and then reaches the first optical channel and is output; The horizontally polarized light incident from the second optical channel passes through the fourth filter and then reaches the first reflecting diaphragm. After being reflected by the first reflecting diaphragm, it passes through the second aisle to reach the second filter, is reflected by the second filter and then reaches the third filter, is transmitted by the third filter and then reaches the second reflecting diaphragm. After being reflected by the second reflecting diaphragm, it passes through the first aisle to reach the first filter, is reflected by the first filter and then reaches the PBS prism, is transmitted by the PBS prism and then reaches the first optical channel and is output; The horizontally polarized light incident from the third optical channel is rotated into vertically polarized light by the rotator and then reaches the third reflecting diaphragm. After being reflected by the third reflecting diaphragm, it reaches the PBS prism, is reflected by the PBS prism and then reaches the first optical channel and is output; The horizontally polarized light incident from the fourth optical channel is reflected by the third reflecting diaphragm and then reaches the third filter. After being reflected by the third filter, it reaches the second reflecting diaphragm. After being reflected by the second reflecting diaphragm, it passes through the first aisle to reach the first filter, is reflected by the first filter and then reaches the PBS prism, is transmitted by the PBS prism and then reaches the first optical channel and is output; The horizontally polarized light incident from the fifth optical channel is reflected by the third reflecting diaphragm and then reaches the fourth filter. After being reflected by the fourth filter, it reaches the first reflecting diaphragm. After being reflected by the first reflecting diaphragm, it passes through the second aisle to reach the second filter, is reflected by the second filter and then reaches the third filter, is transmitted by the third filter and then reaches the second reflecting diaphragm. After being reflected by the second reflecting diaphragm, it passes through the first aisle to reach the first filter, is reflected by the first filter and then reaches the PBS prism, is transmitted by the PBS prism and then reaches the first optical channel and is output.

2. A wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals as described in claim 1, characterized in that, A fifth filter is installed at the second optical channel for transmitting one of the lights incident at the second optical channel.

3. A wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals as described in claim 1, characterized in that, The carrier includes a mother carrier and an embedded carrier. The first mounting surface and the second mounting surface are provided on the mother carrier, and an installation groove is provided on the mother carrier for the embedded carrier to be embedded. The third mounting surface, the fourth mounting surface and the fifth mounting surface are provided on the embedded carrier.

4. A wavelength division multiplexing structure for multi-wavelength and narrow wavelength intervals according to claim 1, characterized in that, The third reflective diaphragm includes three independent reflective diaphragms, and the three reflective diaphragms respectively correspond to the third filter, the fourth filter, and the fifth filter one by one.

5. A wavelength division multiplexing structure for multi-wavelength and narrow wavelength interval according to claim 2, characterized in that: The first filter transmits light with a wavelength of 1631.4 nm and reflects light with other wavelengths; The second filter transmits light with a wavelength of 1650.9 nm and reflects light with other wavelengths; The third filter reflects light with a wavelength of 1529.2 nm and transmits light with other wavelengths; The fourth filter reflects light with a wavelength of 1578.2 nm and transmits light with other wavelengths; The fifth filter transmits light with a wavelength of 1680.2 nm and reflects light with other wavelengths.

6. A wavelength division multiplexing structure for multiple wavelengths and narrow wavelength intervals according to claim 1, characterized in that, The carrier adopts a metal bracket.

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