Miniature fixed optical add-drop multiplexer

Abstract

The utility model relates to a wavelength division multiplexing technology, in particular to a miniature fixed optical add-drop multiplexer, which comprises a first device and a second device which are cascaded through a common optical fiber and are four-port devices, and one port of the first device and one port of the second device are used as transmission ports; one of the other three ports of the first device is used as a common port; the other two ports are used as reflecting ends; and one of the other three ports of the second device is used as a common end for outputting optical signals, and the other two ports are used as reflection ends for inputting the optical signals. Compared with a device used for box type packaging in the market, the volume size is obviously reduced, a steel pipe of a branching device can be directly used for packaging, the use volume is greatly reduced, the structure is exquisite, the economic value and the use value are great, the technological structure is simple, the volume is small, and production is convenient.

Description

Technical Field

[0001] This utility model relates to wavelength division multiplexing technology, specifically a miniature fixed optical add-drop multiplexer. Background Technology

[0002] WDM (Wavelength Division Multiplexing) technology has completely changed the way people communicate. Its huge bandwidth, excellent high speed and transparency make it the preferred technology in the field of fiber optic communication today.

[0003] The technical principle of thin-film filter type FOADM (Fixed Optical Add / Drop Multiplexer) is mainly based on the interference and filtering effects of optical thin films.

[0004] Optical thin films are typically composed of multiple layers of materials with different refractive indices, each with precisely designed thickness and refractive index. When light waves pass through these thin film layers, they are reflected and transmitted at different interfaces, accompanied by phase changes. These reflected and transmitted lights interfere with each other, forming a specific spectral response.

[0005] In the operation of a FOADM, the input multi-wavelength optical signal first passes through a beam splitter to separate the different wavelengths. Then, these separated optical signals enter their respective thin-film filters. Based on preset wavelength selection characteristics, the thin-film filters reflect or transmit the target wavelength optical signal to the output port, allowing for the addition or removal of optical signals. Finally, the processed optical signals are recombined and transmitted to the next optical network node.

[0006] Traditional cascaded structures require the combination of two three-port devices operating in the same frequency band, which not only increases the complexity of the equipment but also makes the entire module occupy a large space. Furthermore, to ensure that these devices function properly, a suitable enclosure is needed, further increasing the overall module size. Utility Model Content

[0007] The purpose of this invention is to provide a miniature fixed optical add-drop multiplexer to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A miniature fixed optical add-drop multiplexer includes a first device and a second device cascaded through a common optical fiber, the first device and the second device having the same structure.

[0010] Both the first device and the second device are four-port devices. One port of the first device and one port of the second device serve as transmission ports for cascading the first device and the second device through the common optical fiber.

[0011] One of the other three ports of the first device is used as a common terminal for optical signal input; the other two ports are used as reflective terminals for optical signal output.

[0012] One of the other three ports of the second device is used as a common terminal for optical signal output, and the other two ports are used as reflective terminals for optical signal input.

[0013] The miniature fixed optical add-drop multiplexer described above: the first device is provided with a large glass tube on the outside, a three-fiber collimator is provided at one end of the large glass tube, and a single-fiber collimator is provided at the other end of the large glass tube.

[0014] The transmission end is located at one end of the single-fiber collimator, while the common end and the reflection end are integrated at one end of the three-fiber collimator.

[0015] As described above, the miniature fixed optical add-drop multiplexer includes a second small glass tube, with a single-fiber pigtail and a spherical lens fixedly disposed at both ends of the second small glass tube, respectively.

[0016] The single-fiber pigtails in the single-fiber collimators of the first and second devices are connected by a common optical fiber.

[0017] As described above, the miniature fixed optical add-drop multiplexer includes a first small glass tube, through which a fixed three-fiber pigtail is inserted. A self-focusing lens is provided at the end of the three-fiber pigtail away from the first small glass tube, a first filter is provided at the end of the self-focusing lens away from the three-fiber pigtail, and a second filter is provided at the end of the first filter away from the self-focusing lens.

[0018] The miniature fixed optical add-drop multiplexer described above: the first device, the second device, and the common optical fiber are all encapsulated in a steel tube, and a rubber plug is provided at the opening of the steel tube.

[0019] An optical fiber connecting the common end and the reflective end of the first device extends out of the encapsulation steel tube through a rubber plug; an optical fiber connecting the common end and the reflective end of the second device also extends out of the encapsulation steel tube through a rubber plug.

[0020] As described above, the miniature fixed optical add-drop multiplexer has one end of a single-fiber pigtail as a pigtail, and the other end is ground to form an 8° surface and coated with an anti-reflection film; the spherical lens has one end corresponding to the 8° surface of the single-fiber pigtail as an 8° inclined surface, while the other end is a sphere, and both ends are coated with anti-reflection films.

[0021] As described above, the miniature fixed optical add-drop multiplexer has a three-fiber pigtail at one end and is ground to form an 8° surface at the other end, which is coated with an anti-reflection film. The self-focusing lens has an 8° angle on one side facing the three-fiber pigtail and a 0° angle on the other side, with anti-reflection films coated at both ends.

[0022] Compared with the prior art, the beneficial effects of this utility model are: both the first device and the second device are encapsulated in the encapsulation steel tube, so there is only one bend in the common optical fiber, and the steel tube encapsulation method can be used directly, which greatly reduces the structural size of the entire device.

[0023] Compared to devices using box-type packaging on the market, its size is significantly reduced. It can be directly packaged using the steel tube of the splitter, and the size can be reduced to L30xW7xH4mm, greatly reducing the usage volume. It can meet the requirements of simple FOADM design. Its structure is ingenious, with great economic and practical value. The process structure is simple, the size is small, and it is convenient to produce. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a miniature fixed optical add-drop multiplexer.

[0025] Figure 2 This is a schematic diagram of the internal structure of a miniature fixed optical add-drop multiplexer.

[0026] Figure 3 This is a schematic diagram of the structure of a single-fiber collimator in a miniature fixed optical add-drop multiplexer.

[0027] Figure 4 This is a schematic diagram of the three-fiber collimator in a miniature fixed optical add-drop multiplexer.

[0028] Figure 5 This is a schematic diagram of the final packaged structure of a miniature fixed optical add-drop multiplexer.

[0029] In the diagram: 1-First device; 11-Three-fiber collimator; 12-Single-fiber collimator; 13-Large glass tube; 111-First small glass tube; 112-Three-fiber pigtail; 113-Self-focusing lens; 114-First filter; 115-Second filter; 121-Second small glass tube; 122-Single-fiber pigtail; 123-Spherical lens; 2-Second device; 3-Common optical fiber; 4-Rubber stopper; 5-Encapsulating steel tube. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0031] Please see Figures 1-5 As an embodiment of the present invention, the miniature fixed optical add-drop multiplexer includes a first device 1 and a second device 2 cascaded through a common optical fiber 3, and the first device 1 and the second device 2 have the same structure.

[0032] Both the first device 1 and the second device 2 are four-port devices. One port of the first device 1 and one port of the second device 2 serve as transmission ports for cascading the first device 1 and the second device 2 through the common optical fiber 3.

[0033] One of the other three ports of the first device 1 is used as a common terminal for optical signal input; the other two ports are used as reflection terminals for optical signal output.

[0034] One of the other three ports of the second device 2 is used as a common terminal for optical signal output, and the other two ports are used as reflective terminals for optical signal input.

[0035] In this embodiment, the optical signal enters from the common terminal of the first device 1, one reflected optical signal is output from one of the reflection terminals of the second device 2, and the other reflected optical signal is output from the other reflection terminal of the second device 2, while the transmitted optical signal is output from the common terminal of the second device 2.

[0036] Correspondingly, the optical signal can also be input from the common terminal of the second device 2, one reflected optical signal is output from one of the reflection terminals of the first device 1, and the other reflected optical signal is output from the other reflection terminal of the first device 1, while the transmitted optical signal is output from the common terminal of the first device 1.

[0037] As a further embodiment of the present invention, a large glass tube 13 is provided on the outside of the first device 1, a three-fiber collimator 11 is provided at one end of the inside of the large glass tube 13, and a single-fiber collimator 12 is provided at the other end of the inside of the large glass tube 13.

[0038] The transmission end is located at one end of the single-fiber collimator 12, and the common end and the reflection end are integrated at one end of the three-fiber collimator 11.

[0039] In this embodiment, a three-fiber collimator 11 is used to collimate a small-mode beam transmitted within the optical fiber into a large-mode beam, enabling it to transmit over a longer distance. A single-fiber collimator 12 is also used to collimate a small-mode beam transmitted within the optical fiber into a large-mode beam, increasing the transmission distance, especially when applied to bend-resistant optical fibers. When the optical fiber signal is transmitted between the transmission ends of the first device 1 and the second device 2, it is collimated by the single-fiber collimator 12 and transmitted undistorted in the common optical fiber 3. The large glass tube 13 is mainly used to fix and connect the three-fiber collimator 11 and the single-fiber collimator 12 in the same device, acting as a connecting bridge. The large glass tube 13 is made of high borosilicate glass.

[0040] As a further embodiment of the present invention, the single fiber collimator 12 includes a second small glass tube 121, and a single fiber pigtail 122 and a spherical lens 123 are respectively fixedly disposed at both ends of the second small glass tube 121.

[0041] The single fiber pigtail 122 in the single fiber collimator 12 of the first device 1 and the second device 2 are connected by a common optical fiber 3.

[0042] In this embodiment, the second small glass tube 121 is also made of borosilicate glass and is used as a connecting bridge to connect the single-fiber pigtail 122 and the spherical lens 123. The single-fiber pigtail 122 is formed by inserting an optical fiber into a single-hole capillary tube and then bonding and curing it with adhesive. One end serves as a pigtail, and the other end is ground to form an 8° surface and coated with an anti-reflection film to adapt to the bending-resistant optical fiber.

[0043] The spherical lens 123 mainly refracts the light beam through the curvature of the spherical surface, thereby collimating or focusing the light beam. One end of it, which corresponds to the 8° surface of the single-fiber pigtail 122, is also an 8° inclined surface, while the other end is a spherical surface. Both ends are coated with anti-reflective coatings.

[0044] As a further embodiment of this utility model, the three-fiber collimator 11 includes a first small glass tube 111, through which a fixed three-fiber pigtail 112 is threaded. A self-focusing lens 113 is provided at the end of the three-fiber pigtail 112 away from the first small glass tube 111, a first filter 114 is provided at the end of the self-focusing lens 113 away from the three-fiber pigtail 112, and a second filter 115 is provided at the end of the first filter 114 away from the self-focusing lens 113.

[0045] In this embodiment, the first small glass tube 11 is also made of high borosilicate glass, which serves as a sealing drum. The three-fiber pigtail 112 is formed by inserting an optical fiber into a three-hole capillary tube and then fixing it with glue. One end is a pigtail, and the other end is ground to form an 8° surface and coated with an anti-reflective film.

[0046] Correspondingly, the self-focusing lens 113 has an 8° angle on one side facing the three-fiber pigtail 112 and a 0° angle on the other side, with anti-reflection coatings on both ends; while the first filter 114 and the second filter 115 are both rectangular crystals, made of glass substrate, and composed of dozens of layers of dielectric films of different materials, refractive indices and thicknesses, with a reflective film on one side and an anti-reflection film on the other.

[0047] As a further embodiment of this utility model, the first device 1, the second device 2, and the common optical fiber 3 are all encapsulated in an encapsulation steel tube 5, and a rubber plug 4 is provided at the opening of the encapsulation steel tube 5.

[0048] The optical fiber connecting the common end and the reflective end of the first device 1 passes through the rubber plug 4 and extends out of the encapsulation steel tube; the optical fiber connecting the common end and the reflective end of the second device 2 also passes through the rubber plug 4 and extends out of the encapsulation steel tube.

[0049] In this embodiment, both the first device 1 and the second device 2 are encapsulated in the encapsulation steel tube 5. Therefore, there is only one bend in the common optical fiber 3, and the steel tube encapsulation method can be directly used, which greatly reduces the structural size of the entire device.

[0050] Compared to devices using box-type packaging on the market, its size is significantly reduced. It can be directly packaged using the steel tube of the splitter, and the size can be reduced to L30xW7xH4mm, greatly reducing the usage volume. It can meet the requirements of simple FOADM design. Its structure is ingenious, with great economic and practical value. The process structure is simple, the size is small, and it is convenient to produce.

[0051] The above embodiments are exemplary and not restrictive. Therefore, without departing from the spirit or basic characteristics of this utility model, any technical solutions that can be implemented in other specific forms are included in this utility model.

Claims

1. A miniature fixed optical add-drop multiplexer, comprising a first device (1) and a second device (2) cascaded via a common optical fiber (3), wherein the first device (1) and the second device (2) have identical structures, characterized in that, The first device (1) and the second device (2) are both four-port devices. One port of the first device (1) and one port of the second device (2) serve as transmission ports for cascading the first device (1) and the second device (2) through the common optical fiber (3). One of the other three ports of the first device (1) is used as a common terminal for optical signal input; the other two ports are used as reflection terminals for optical signal output. One of the other three ports of the second device (2) is used as a common terminal for optical signal output, and the other two ports are used as reflective terminals for optical signal input.

2. The miniature fixed optical add-drop multiplexer according to claim 1, characterized in that, The first device (1) is provided with a large glass tube (13) on the outside. A three-fiber collimator (11) is provided at one end of the large glass tube (13), and a single-fiber collimator (12) is provided at the other end of the large glass tube (13). The transmission end is located at one end of the single fiber collimator (12), and the common end and the reflection end are integrated at one end of the three fiber collimator (11).

3. A miniature fixed optical add-drop multiplexer according to claim 2, characterized in that, The single-fiber collimator (12) includes a second small glass tube (121), and a single-fiber pigtail (122) and a spherical lens (123) are fixedly installed at both ends of the second small glass tube (121); The single fiber pigtail (122) in the single fiber collimator (12) of the first device (1) and the second device (2) are connected by a common optical fiber (3).

4. A miniature fixed optical add-drop multiplexer according to claim 3, characterized in that, The three-fiber collimator (11) includes a first small glass tube (111), through which a three-fiber pigtail (112) is fixed. A self-focusing lens (113) is provided at the end of the three-fiber pigtail (112) away from the first small glass tube (111), a first filter (114) is provided at the end of the self-focusing lens (113) away from the three-fiber pigtail (112), and a second filter (115) is provided at the end of the first filter (114) away from the self-focusing lens (113).

5. A miniature fixed optical add-drop multiplexer according to claim 1, characterized in that, The first device (1), the second device (2), and the common optical fiber (3) are all encapsulated in a steel tube (5), and a rubber plug (4) is provided at the opening of the steel tube (5). The optical fiber connecting the common end and the reflective end of the first device (1) passes through the rubber plug (4) and extends out of the encapsulation steel tube; the optical fiber connecting the common end and the reflective end of the second device (2) also passes through the rubber plug (4) and extends out of the encapsulation steel tube.

6. A miniature fixed optical add-drop multiplexer according to claim 4, characterized in that, One end of the single-fiber tail (122) is used as a tail, and the other end is ground to form an 8° surface and coated with an anti-reflective film; the spherical lens (123) is also an 8° inclined surface at one end corresponding to the 8° surface of the single-fiber tail (122), while the other end is a spherical surface, and both ends are coated with an anti-reflective film.

7. A miniature fixed optical add-drop multiplexer according to claim 6, characterized in that, One end of the three-fiber tail (112) is a tail fiber, and the other end is ground to form an 8° surface and coated with an anti-reflective film; the self-focusing lens (113) has an 8° surface on one side facing the three-fiber tail (112) and a 0° surface on the other side, and both ends are coated with an anti-reflective film.

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