KR102591998B1 - Attenuator type optical device having optical wave filter - Google Patents

Abstract

Provided is an attenuator-type optical device including an optical wave filter, which is compliant with any of normal, low-density, and high-density wavelength division multiplexing (WDM, CWDM, DWDM), is miniaturized to respond to a recently exploding optical communication system effectively, and sufficiently satisfies the characteristics required for optical communications. The optical device of the present invention comprises: a filter element unit containing a thin film wavelength filter; and a fixing unit disposed outside the filter element unit and including a fixing key to cause the end of a ferrule body to form an 8-degree angle for an optical signal, wherein the fixing key is inserted into a frame gap of a frame where the filter element unit is inserted and is inserted into a fixing hole on an outer housing that accommodates the filter element unit and the frame.

Description

Attenuator type optical device having optical wave filter}

The present invention relates to an attenuator-type optical device, and more specifically, to an attenuator-type optical device that can implement devices of desired wavelengths such as optical signals, CWDM, and DWDM by applying an optical wavelength filter.

Wireless communication is developing into the Internet of Things, which connects things and sparks digital innovation. In addition, the era of ultra-latency connectivity is coming, where various devices including sensors, which are a key means of promoting the production, distribution, and utilization of data, are connected. In the era of ultra-latency connectivity, large-capacity data traffic is required as communication frequency signals for multiple services are integrated due to the explosive increase in data traffic, convergence of broadcasting and communications, and increased use of cloud. For this purpose, in a high-speed optical communication network, an optical element containing an optical wavelength filter is needed to enable two-way transmission of a specific wavelength of the desired service optical signal of the system equipment. In addition, the importance of optical devices including optical wavelength filters for high integration, miniaturization, and low cost is increasing. In particular, for effective use of optical communication systems using a wavelength band of 1260 to 1650 nm, miniaturization of optical devices including optical wavelength filters is required.

Meanwhile, various optical wavelength filters are proposed in Korean Patent No. 10-2081100, Japanese Patent Publication No. 2005-283727, and U.S. Patent No. 6,487,342. However, conventional optical wavelength filters are used in optical communication systems, and their unit cost is high. Accordingly, while complying with normal, coarse, and dense wavelength division multiplexing (WDM, CWDM, DWDM), miniaturization is achieved, and the connector is used in the form of an attenuator to operate the transmission network in the current optical communication system, which is rapidly increasing in recent years. There is a need for an optical device including an optical wavelength filter that is effectively applied to . In addition, it must satisfy the characteristics required for optical communication, such as being easily compatible with existing connectors, easy to install, inexpensive, and low installation cost.

The problem to be solved by the present invention is to effectively respond to the recent explosion of optical communication systems by achieving miniaturization while meeting any of normal, low-density, and high-density wavelength division multiplexing (WDM, CWDM, DWDM), and to meet the requirements of optical communication transmission networks. The aim is to provide an attenuator-type optical device that includes a miniaturized optical wavelength filter that sufficiently satisfies the characteristics.

An attenuator-type optical element including an optical wavelength filter to solve the problem of the present invention is disposed outside the filter element portion and the filter element portion including the thin film wavelength filter, and the end of the ferrule body is angled at an 8 degree angle with respect to the optical signal. It includes a fixing part including a fixing key to achieve. At this time, the fixing key is inserted into the frame gap of the frame into which the filter element unit is inserted, and is inserted into a fixing hole of the outer housing that accommodates the filter element unit and the frame.

In the optical device of the present invention, the filter element portion includes first and second ferrule portions, and a protective tube may be disposed between first and second steps of each of the first and second ferrule portions. The tube may be made of ceramic material. The cross-sections of the first and second ferrule bodies may be polished at an angle of 8 degrees and coated with an anti-reflective coating. The first ferrule portion may be press-fitted into a glass tube. A male cap is inserted into one side of the outer housing, and the male cap accommodates the first portion of the filter element unit.

In the preferred optical device of the present invention, a portion of the second portion of the filter element portion may be embedded in the elastic portion. The fixing part includes a support tube, a flange, and the fixing key, and the fixing key is formed on the flange. The fixing key maintains an angle of 8 degrees with respect to the optical signal.

According to the optical device in the form of an attenuator including the optical wavelength filter of the present invention, by applying a fixing part that maintains an 8 degree angle with respect to the optical signal at the end of the ferrule body, normal, coarse and high density It conforms to any one of (dense) wavelength division multiplexing (WDM, CWDM, DWDM) and is miniaturized to effectively respond to the recent explosion of optical communication transmission systems. It satisfies the following characteristics: It is easily compatible with existing optical connectors, is simple to install, is inexpensive, and has low installation costs.

1 is an exploded view showing an optical device according to the present invention.
Figure 2 is an exploded view for explaining the wavelength filter element according to the present invention.
Figures 3 and 4 are cross-sectional process views showing the process of manufacturing the filter element according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The embodiments described below may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described in detail below. Examples of the present invention are provided to more completely explain the present invention to those skilled in the art. In the drawing, the representation is exaggerated for convenience of explanation. Meanwhile, terms indicating location, such as top, bottom, front, etc., are only related to what is shown in the drawing. In practice, the optical element can be used in any optional orientation, and in actual use, the spatial orientation changes depending on the orientation and rotation of the optical element (this is the part that defines in advance which orientation the drawing is drawn in. It has nothing to do with technology) do).

An embodiment of the present invention applies a fixing part that maintains an 8-degree angle at the end of the ferrule body, thereby enabling normal, coarse and dense wavelength division multiplexing (WDM, CWDM, DWDM). We propose an attenuator-type optical device that satisfies any of the above requirements, is miniaturized, effectively responds to the recent explosion of optical communication transmission systems, and includes an optical wavelength filter that sufficiently satisfies the characteristics required by optical communication networks. To this end, the structure of an attenuator-type optical device to which an optical wavelength filter is applied will be studied in detail, and a method of manufacturing an attenuator-type optical device including the wavelength filter will be described in detail.

The optical wavelength filter element according to an embodiment of the present invention is installed in advance in optical communication system equipment and blocks and adjusts the wavelength of the optical signal being serviced to maintain the system equipment stably. Additionally, the optical communication network of the present invention uses a wavelength band of 1260 to 1650 nm. In practice, an attenuator-type optical element containing a wavelength filter can be used for any selective specific wavelength band, and in practical applications, a C-type lens and a stub ferrule, or a G-type lens and a stub ferrule depending on the angular direction of the stub ferrule. Insertion loss varies greatly depending on the fine alignment of the XYZ axes.

Figure 1 is an exploded view showing an attenuator-type optical device 100 including an optical wavelength filter according to an embodiment of the present invention. However, it is not a drawing in the strict sense, and there may be components not shown in the drawing for convenience of explanation.

According to FIG. 1, an attenuator-type optical device 100 including a wavelength filter includes a filter element portion 10 including a wavelength filter, a filter receiving portion 20, and a fixing portion 30. The filter element unit 10 sends and inserts a specific wavelength of the optical signal to match the wavelength element in any one of normal, coarse and dense wavelength division multiplexing (WDM, CWDM, DWDM). The device is manufactured with low loss. For convenience of explanation, the fixing part 30 is divided into a first part (A) and a second part (B) centered on the metal flange 32. The filter element unit 10 will be described in detail later.

The filter receiving part 20 has a built-in filter element part 10, a male cap 21, an outer housing 22, a frame 23, an elastic part 24, a connecting tube 25, and a fixing member. It includes a holder 26 and a female cap 27. The male cap 21 is inserted into the frame 23 and accommodates the first portion A of the filter element portion 10. The male cap 21 is inserted into the outer housing 22 to prevent dust, foreign substances, etc. from penetrating into the optical device 100. The outer housing 22 is preferably made of a metal material, and the elastic portion 24 serves to provide elastic force like a spring. The connecting tube 25 is made of a ceramic material such as zirconia and preferably has a cylindrical shape.

The outer housing 22 is preferably made of a conductive material, such as a metal material, in order to block electromagnetic waves, and is preferably made of a material that has excellent resistance and reliability to temperature and humidity and is advantageous to shock. A portion of the male cap 21 and the filter element portion 10 are exposed on one side of the outer housing 22, and the other side is closed with a female cap 27. The frame 23, when utilized in a known manner, also serves as a fixing key to maintain the angle at which the filter element unit 10 is inserted (angle with respect to the optical signal) at 8 degrees. The first portion (A) of the filter element portion 10 is received in the frame 23 through the frame gap 23a. Specifically, the fixing key 33 is inserted into the frame gap 23a and finally into the fixing hole 22a located at the center of the outer housing 22. In this case, the filter element unit 10 and the frame 23 are firmly fixed to the outer housing 22.

The elastic part 24 is made of a spring-like material, and the elastic part 24 contains part of the second part B. That is, the elastic portion 24 is disposed between the flange 32 and the step 26a of the fixed holder. At this time, the flange 32 is preferably made of metal. The elastic portion 24 adjusts tension to push the filter element portion 10 and firmly couple it to the frame 23. When the filter element unit 10 is coupled to the frame 23 with the help of the elastic unit 24, the filter element unit 10 does not move even when an external force is applied. Meanwhile, the elastic portion 24 serves to firmly couple the filter element portion 10 to the fixing key hole in the frame 23, and may be modified in various ways within the scope of the present invention.

The connecting tube 25 is disposed between the flange 32 and the female cap 27 and receives the second part B. The connecting tube 25 is inserted into the hole 26b of the fixed holder 26. In other words, the first part (A) is inserted into the 8-degree fixing key hole in the frame gap (23a), and the first part (A) is received in the male cap (21). The second part (B) is inserted into the hole (26b) of the fixing holder while being accommodated in the connecting tube (25). In this case, the male cap 21, frame 23, filter element part 10, elastic part 24, connecting tube 25, and fixing holder 26 become an integrated assembly, forming an outer housing ( 22) is built in. When the assembly is embedded in the outer housing 22, the female cap 27 is used to finish the assembly so that it is embedded in the outer housing 22.

Figure 2 is an exploded view showing the filter element unit 10 according to an embodiment of the present invention. At this time, the optical device 100 will be referred to in FIG. 1 . Here, the filter element unit 10 is presented as an example, and may be modified in various ways within the scope of the present invention.

According to FIG. 2, the filter element portion 10 includes a first ferrule portion 11 and a second ferrule portion 13 spaced apart by a predetermined distance. The first ferrule portion 11 includes, for example, a first ferrule body 11a such as a stub ferrule and a first lens 11c such as a C type lens. The second ferrule portion 13 includes, for example, a second ferrule body 13a such as a stub ferrule and a second lens 13c such as a G type lens. At this time, since the first and second ferrule bodies 11a and 13a and the first and second lenses 11c and 13c are already well known, detailed description thereof will be omitted. The ends of the first and second ferrule bodies 11a and 13a are polished to 8 degrees and then subjected to anti-reflection coating. The first ferrule body 11a includes a first step 11b, and the second ferrule portion 13 includes a second step 13b.

The first ferrule body 11a and the first lens 11c are finely aligned along the XYZ axes along the angular direction to reduce insertion loss, and the glass tube 12 is inserted and hardened with EMI3410 epoxy or the like. The thin film wavelength filter 14 is fixed with epoxy to one surface of the second ferrule body 13a and the second lens 13c, and the insertion loss of the . Within the scope of the present invention, the first and second lenses 11c and 13c may be appropriately selected and applied from spherical lenses, aspherical lenses, GRIN lenses, C-type lenses, G-type lenses, etc.

The thin film wavelength filter 14 functions to transmit a single light wavelength by radiating collimated optical signals from the first ferrule body 11a and the first lens 11c as parallel light. At this time, the first ferrule body 11a is polished to 8 degrees and then has an anti-reflective coating applied thereto. The thin film wavelength filter 14 is compatible with normal, coarse and dense wavelength division multiplexing (WDM, CWDM, DWDM). The thin film wavelength filter 14 can transmit only specific wavelengths of optical signals and reflect some of them. The degree to which the specific wavelength of light and insertion loss are transmitted may vary depending on the purpose and characteristics of the optical device 100. Although not shown in the drawings, a known special filter means may be separately disposed between the first and second ferrule portions 11 and 13.

The portion of the first ferrule body (11a) in contact with the first lens (11c) and the portion of the second ferrule body (13a) in contact with the second lens (13c) are polished at an 8-degree inclination to increase light transparency. An anti-reflective coating may be applied. The 8-degree inclined polishing reduces insertion loss and increases the light transmittance, and the anti-reflective coating allows optical signals to pass easily, thereby reducing light loss. A cylindrical protective tube 15 made of a ceramic material such as zirconia is disposed between the first and second steps 11b and 13b, and within the protective tube 15, the first ferrule body 11a has a smaller diameter. In the true part, the first lens 11c, the thin film wavelength filter 14, the second lens 13c, and the second ferrule body 13a are built with a smaller diameter part. The first and second ferrule bodies 11a and 13a include optical fibers in a path through which optical signals are transmitted. The filter element portion 10 including the first and second ferrule portions 11 and 13 adopts an attenuator shape.

An 8 degree angle fixing part 30 is coupled to the outside of the filter element unit 10, specifically the outside of the protection tube 15. The fixing part 30 consists of a cylindrical support tube 31 made of a ceramic material such as zirconia, a flange 32, and a fixing key 33. The support tube 31 supports the fixing part 30 while surrounding the protection tube 15. The fixing key 33 is provided to protrude from the flange 32 made of metal, is inserted into the frame gap 23a, and is finally inserted into the fixing hole 22a of the outer housing 22. In this case, the filter element unit 10 and the frame 23 are integrated and fixed to the outer housing 22. In this way, even if an external force acts on the optical device 100, the insertion angle of the filter device 10 is maintained at 8 degrees, so insertion loss is small when connecting the external connector.

Figures 3 and 4 are cross-sectional views showing the process of manufacturing the filter element unit 10 according to an embodiment of the present invention. At this time, the optical device 100 will be referred to in FIG. 1 .

According to FIG. 3, the method of manufacturing the filter element portion 10 first prepares the first and second ferrule portions 11 and 13. Specifically, the first ferrule body (11a) on which the first step (11b) is formed is manufactured by polishing at an angle of 8 degrees and then applying an anti-reflective coating. That is, one end surface of the first ferrule body 11a is ground at an 8-degree angle to reduce insertion loss, and an anti-reflective coating is applied to the end surface. Thereafter, the first lens 11c is aligned with the first ferrule body 11a so that the insertion loss is less than 0.2 dB, and then bonded with an adhesive such as epoxy to complete the first ferrule portion 11. When the alignment of the first ferrule body (11a) and the first lens (11c) is completed, the first ferrule body (11a) and the first lens (11c) are bonded to the glass tube 12 with EMI-3410 epoxy, etc. and hardened. Do. At this time, it is preferable that one side of the glass tube 12 is in contact with the first step 11b.

The second ferrule body (13a) on which the second step (13b) is formed is manufactured by polishing at an angle of 8 degrees and applying an anti-reflective coating. That is, one end surface of the second ferrule body 13a may be ground at an 8-degree angle to reduce insertion loss, and the end surface may be subjected to anti-reflection coating. Thereafter, the second lens 13c is aligned with the second ferrule body 13a and then bonded with an adhesive such as epoxy to complete the second ferrule portion 13. When the alignment of the second ferrule body 13a and the second lens 13c is completed, a thin film wavelength filter 14 is placed on one side of the second lens 13c, for example, along the angular direction so that the insertion loss is less than 0.25 dB. Finely align the XYZ axes and bond them with an adhesive such as epoxy. The thin film wavelength filter 14 transmits a specific desired wavelength by radiating collimated optical signals from the first ferrule portion 11 as parallel light, and makes it possible to manufacture a device with a small insertion chamber.

According to Figure 4, the diameter of the portion where the diameter is reduced in the first ferrule body (11a), the first lens (11c), the thin film wavelength filter 14, the second lens (13c), and the second ferrule body (13a) have a smaller diameter. The smaller part is embedded in the protective tube (15). That is, the protective tube 15 is made of a material such as ceramic, and is disposed between the first and second steps 11b and 13b. A fixing part 30 consisting of a support tube 31, a flange 32, and a fixing key 33 is disposed outside the protection tube 15. The fixing key 33 provided on the flange 32 is inserted into the frame gap 23a and finally inserted into the fixing hole 22a of the outer housing 22. In this case, the filter element unit 10 and the frame 23 are firmly fixed to the outer housing 22, and the angle at which the filter element unit 10 is inserted is maintained at 8 degrees.

The optical device 100 according to an embodiment of the present invention is applied to existing attenuator types such as SC/PC, SC/APC, FC/PC, FC/APC, LC/PC, LC/APC, etc. and is easily compatible with existing connectors. It is easy to install, has low installation costs for transmitting multiple wavelengths of CWDM and DWDM in an optical communication multi-channel transmission network, and requires low maintenance costs. Additionally, since the optical device 100 of the present invention is manufactured by a simple method, it is inexpensive.

Above, the present invention has been described in detail with preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. possible.

10; optical device
11, 13; First and second ferrule parts
11a, 13a; First and second ferrule bodies
11b, 13b; 1st and 2nd steps
11c, 13c; first and second lenses
12; glass tube 14; wavelength filter
15; protective tube 20; filter receiver
21; mail cap 22; outer housing
23; frame 24; elastic part
25; connecting tube 26; Fixed holder
27; female cap 30; fixed part
31; support tube 32; flange
33; sticky key

Claims (9)

A filter element unit including a thin film wavelength filter; and
It is disposed outside the filter element unit and includes a fixing part including a fixing key that allows the end of the ferrule body and the lens to form an 8-degree angle with respect to the optical signal,
The fixing part includes a support tube, a flange, and the fixing key, and the fixing key is provided to protrude from the flange,
The fixing key is inserted into the frame gap of the frame into which the filter element unit is inserted, and is inserted into a fixing hole of the outer housing that accommodates the filter element unit and the frame, and the fixing key is finally inserted into the fixing hole. An attenuator-type optical device that includes an optical wavelength filter. The optical wavelength filter according to claim 1, wherein the filter element unit includes first and second ferrule units, and a protective tube is disposed between first and second steps of each of the first and second ferrule units. An attenuator-type optical device containing a. The optical device of claim 2, wherein the protective tube is made of a ceramic material. The optical device in the form of an attenuator including an optical wavelength filter according to claim 2, wherein cross-sections of the first and second ferrule bodies are polished at an angle of 8 degrees and coated with an anti-reflection coating. The optical device of claim 2, wherein the first ferrule portion is press-fitted into a glass tube. The optical device in the form of an attenuator including an optical wavelength filter according to claim 1, wherein a male cap is inserted into one side of the outer housing, and the male cap accommodates the first portion of the filter element unit. The optical device in the form of an attenuator including an optical wavelength filter according to claim 1, wherein a portion of the second portion of the filter device portion is embedded in an elastic portion. delete The optical device of claim 1, wherein the fixing key maintains an angle of 8 degrees with respect to the optical signal.

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