TWM637681U - Optical fiber network signal access module that can improve reflection isolation - Google Patents

Abstract

The present invention proposes an optical fiber network signal access module capable of improving reflection isolation, including first and second wavelength division multiplexers and optical filters. The first and second wavelength division multiplexers respectively include a common port, a reflection port, a transmission port and a filter element. The common port is connected to the reflection port by the reflection of the filter element, and connected to the signal by the pass function of the filter element. The transmission port, the second wavelength division multiplexer includes another reflection port, the signal is connected to the transmission port by the reflection of the filter element and the signal is connected to the transmission port of the first wavelength division multiplexer; the optical filter includes two communication ports Ports, one of which is connected to the reflection port of the first wavelength division multiplexer, and the other is connected to one of the common port and the reflection port of the second wavelength division multiplexer.

Description

Optical fiber network signal access module that can improve reflection isolation

The present invention relates to the technical field of an optical fiber network signal access module, in particular to an optical fiber network signal access module capable of improving reflection isolation.

Optical fiber is a kind of fiber made of glass or plastic. It is a light transmission tool that uses the principle of total reflection to transmit light in these fibers. It has the advantages of high speed, high capacity, good safety, low loss, light weight, and low cost. , so it has been widely used in the transmission of network signals.

In optical fiber network signal transmission, the working wavelength of the optical fiber can be divided into multiple channels, such as 80 channels, so that a larger amount of data can be transmitted in the same optical fiber. For example, a telecommunications company can use the same optical fiber to Simultaneous transmission of telephone, Internet, cable TV signals. Since different optical signals in the same optical fiber have different wavelengths, a wavelength division multiplexer (Wavelength Division Multiplexing, WDM) must be used to separate the different wavelengths.

Please refer to FIG. 1 , which is a structural diagram of a conventional optical fiber network signal access module disclosed in US Patent No. 5,629,995. As shown in Figure 1, the conventional optical fiber network signal access module 9 includes a first wavelength division multiplexer 91, a second wavelength division multiplexer 92, and amplifiers 93, 94, and the optical signal of wavelength λ1 is transmitted by the first The common port (Common Port) 911 of the wavelength division multiplexer 91 enters, because the filter element 914 of the wavelength division multiplexer A is designed to allow the optical signal of the wavelength λ1 to pass through, so the optical signal of the wavelength λ1 can pass through the filter element 914 And output by the transmission port (Pass Port) 913, after that, the optical signal of wavelength λ1 passes through the amplifier 94 (to increase the signal strength to avoid signal attenuation) and enters from the common port 921 of the second wavelength division multiplexer 92, because the second wavelength division The filter element 924 of the wave multiplexer 92 is designed not to allow the optical signal of the wavelength λ1 to pass through, so the optical signal of the wavelength λ1 will be reflected by the filter element 924 to the reflection port (Reflect Port) 922 for output. On the contrary, the optical signal of wavelength λ2 enters from the reflective port 922 of the second wavelength division multiplexer 92 and passes through the filter element 924 (the filter element 924 is designed to allow the optical signal of wavelength λ2 to pass through) and is output by the transmissive port 923, and then After passing through the amplifier 93, it enters into the reflection port 912 of the first wavelength division multiplexer 91, and then is reflected by the filter element 914 to the common port 911 (the filter element 914 is designed not to allow the optical signal of wavelength λ2 to pass through) for output.

As can be seen from the above, the conventional optical fiber network signal access module 9 shown in FIG. 1 includes two amplifiers 93, 94, which will amplify the noise while increasing the signal strength, so it is generally only suitable for long-term use. In the case of distance signal transmission, because the noise will be attenuated to an undetectable level due to the long distance, and then an amplifier is added to amplify the signal.

However, no matter what kind of transmission occasion, noise (for example, some residual part of the optical signal of the wavelength output from the transmission port that should pass through the filter element is reflected to the output of the reflection port) will interfere with the optical signals of other wavelengths. affect the transmission efficiency.

In order to solve the above-mentioned problem that the conventional optical fiber network signal access module is prone to noise interference, this new system proposes a fiber optic network signal access module with a changed architecture design, which can improve reflection isolation (Isolation) and improve transmission efficiency.

According to the present invention, an optical fiber network signal access module capable of improving reflection isolation is provided, including a first wavelength division multiplexer, including a first common port, a first reflection port, and a first transmission port and a first filter element, the first common port is electrically connected to the first reflection port by the reflection effect of the first filter element, and the first common port is electrically connected by the passing effect of the first filter element In the first transmission port, the first filter element can pass the optical signal of the first wavelength; a second wavelength division multiplexer includes a second common port, a second reflection port, a third reflection port, a A second transmission port and a second filter element, the second common port is telecommunications connected to the second reflection port by the reflection of the second filter element, the second common port is passed by the second filter element Function and telecommunications are connected to the second transmission port, the third reflection port is connected to the second transmission port by the reflection of the second filter element, and the third reflection port is connected to the first transmission port , the second filter element can pass an optical signal of a second wavelength, the second wavelength is different from the first wavelength; and an optical filter includes a first communication port and a second communication port, the first communication port is connected to the first reflection port, and the second communication port is connected to one of the second common port and the second reflection port, wherein the optical filter can isolate the optical signal of the first wavelength.

In the optical fiber network signal access module proposed by the above-mentioned new model that can improve the reflection isolation, a filter is added, and the so-called filter refers to a kind of wavelength (specific wavelength) that can filter The optical signal is filtered out. In other words, when the optical signal of a specific wavelength output from the first transmission port should pass through the first filter element, although the remaining part will be reflected by the first filter element and output from the first reflection port, the signal is connected to the The optical filter of the first reflection port can further filter the optical signal of the specific wavelength, so as to prevent the optical signal of the specific wavelength from being transmitted to the second wavelength division multiplexer and interfere with optical signals of other wavelengths. Therefore, compared with the problem of noise interference in the conventional optical fiber network signal access module, the new model can filter the remaining part of the optical signal of a specific wavelength by using an optical filter, so as to Avoid noise interference, and relatively improve the transmission efficiency, that is, the reflection isolation can be further improved by the optical filter to avoid interference (isolation refers to the light at the output port of the optical component (such as a wavelength division multiplexer) The calculation method of the light energy entering the non-designated output port, the unit is expressed in dB, the higher the better).

Optionally, in a non-limiting exemplary embodiment, the second communication port is signal-connected to the second common port.

Optionally, in a non-limiting exemplary embodiment, the second communication port is signal-connected to the second reflection port.

Optionally, in a non-limiting exemplary embodiment, the isolation of the optical filter to isolate the optical signal of the first wavelength is not less than 30 dB.

According to the present invention, there is provided an optical fiber network signal access module capable of improving reflection isolation in another implementation mode, which includes a first wavelength division multiplexer, including a first common port, a first reflection port, A first transmission port and a first filter element, the first common port is connected to the first reflection port by the reflection of the first filter element, the first common port is connected with the first filter element Telecommunications are connected to the first transmission port by function; a second wavelength division multiplexer includes a second common port, a second reflection port, a second transmission port and a second filter element, the second common The port is electrically connected to the second reflection port by the reflection of the second filter element, the second common port is electrically connected to the second transmission port by the passage of the second filter element, and the second The reflection port is connected to the first reflection port; a third wavelength division multiplexer includes a third common port, a third reflection port, a third transmission port and a third filter element, and the third common port The third common port is electrically connected to the third reflection port by the reflection function of the third filter element, and the third common port is electrically connected to the third transmission port by the passing function of the third filter element, and the third common port The port is connected to the second common port; and a fourth wavelength division multiplexer, including a fourth common port, a fourth reflection port, a fourth transmission port and a fourth filter element, the fourth common port The fourth common port is connected to the fourth reflection port by the reflection function of the fourth filter element, the fourth common port is connected to the fourth transmission port by the passage function of the fourth filter element, and the fourth reflection port The port is connected to the third reflective port.

In the above exemplary implementation, the optical signals for forward and backward transmission are integrated into one module, which is convenient for on-site construction personnel to use flexibly.

Optionally, in a non-limiting exemplary embodiment, the optical signal of the first wavelength added from the second transmission port passes through the second filter element, passes through the third filter element and the fourth filter element The reflection of is output by the fourth common port.

Optionally, in a non-limiting exemplary embodiment, the isolation of the optical signal of the first wavelength reflected by the third filter element and the fourth filter element is not less than 30 dB.

Optionally, in a non-limiting exemplary embodiment, the optical signal of the second wavelength added from the third transmission port passes through the third filter element, passes through the second filter element and the first filter element The reflection is output by the first common port.

Optionally, in a non-limiting exemplary embodiment, the isolation of the second wavelength optical signal reflected by the second filter element and the first filter element is no less than 30 dB.

The optical fiber network signal access module proposed by this model can effectively improve the reflection isolation of optical signals, and prevent the remnants of optical signals of a certain wavelength from interfering with optical signals of other wavelengths. Thus, the transmission efficiency can be effectively improved. Furthermore, on-site construction personnel can carry out wiring according to on-site needs, which improves the flexibility of use.

In conjunction with the accompanying drawings, the technical content of the present invention, its advantages and the effects it can achieve are further described in the form of preferred specific embodiments, but its purpose is only for illustration to facilitate a better understanding, not to Used for restrictions.

FIG. 2 is a structural diagram of an optical fiber network signal access module capable of improving reflection isolation in a first preferred embodiment of the present invention. Figure 2 shows a fiber optic network signal access module 1 that can improve the reflection isolation, in which, in addition to using a wavelength division multiplexer, an optical filter is used to filter optical signals of specific wavelengths to improve different The isolation between the signals of the wavelengths is used to prevent the optical signals of this specific wavelength from interfering with the optical signals of other wavelengths, thereby improving the transmission efficiency and increasing the flexibility of use.

The optical fiber network signal access module 1 shown in FIG. 2 which can improve the reflection isolation includes a first wavelength division multiplexer 11 , a second wavelength division multiplexer 12 and an optical filter 13 . Wherein, the first wavelength division multiplexer 11 and the second wavelength division multiplexer 12 have substantially the same components and functions, and the first wavelength division multiplexer 11 and the second wavelength division multiplexer 12 can be, for example, respectively Coarse Wavelength Division Multiplexing (CWDM), Dense Wavelength Division Multiplexing (DWDM), Lan Wavelength Division Multiplexing (LWDM or LanWDM), medium wavelength Wavelength Division Multiplexing (Metro Wavelength Division Multiplexing, MWDM) and Coexistence Wavelength Division Multiplexing (CExWDM), etc.

Specifically, the first wavelength division multiplexer 11 includes a first common port 111, a first reflection port 112, a first transmission port 113 and a first filter element 114, wherein the first common port 111 is The signal of the first filter element 114 is connected to the first reflection port 112 by the reflection function of the first filter element 114 , and the signal of the first common port 111 is connected to the first transmission port 113 by the pass function of the first filter element 114 . The second wavelength division multiplexer 12 includes a second common port 121, a second reflection port 122, a third reflection port 125, a second transmission port 123 and a second filter element 124, and the second common port 121 is The signal is connected to the second reflection port 122 by the reflection of the second filter element 124, the second common port 121 is connected to the second transmission port 123 by the passage of the second filter element 124, and the third reflection port 125 is The signal is connected to the second transmission port 123 by the reflection of the second filter element 124 , and the third reflection port 125 is connected to the first transmission port 113 of the first wavelength division multiplexer 11 . The second wavelength of the optical signal that can pass through the second filter element 124 of the second wavelength multiplexer 12 is different from the first wavelength of the optical signal that can pass through the first filter element 114 of the first wavelength multiplexer 11 .

The optical filter 13 shown in FIG. 2 also includes a first communication port 131 and a second communication port 132, wherein the first communication port 131 is connected to the first reflection port 112 of the first wavelength division multiplexer 11, And the second communication port 132 is connected to the second common port 121 of the second wavelength division multiplexer 12 .

The transmission process of optical signals with different wavelengths is described in detail below. As shown in Figure 2, after optical signals of different wavelengths λ1, λ3, λ4... enter the first wavelength division multiplexer 11 through the first common port 111 of the first wavelength division multiplexer 11, due to the first wavelength division The first filter element 114 of the wave multiplexer 11 (such as a filter, which uses the different refraction angles of each wavelength to divide and solve the optical signals of different wavelengths) is designed to only allow the optical signal of the first wavelength λ1 to pass through, and the other wavelengths λ3, The light signals of λ4 . . . cannot pass through the first filter element 114 and be reflected.

Therefore, the optical signal of the first wavelength λ1 passes through the first filter element 114 from the first common port 111 and is output from the first transmission port 113, and enters the second wavelength through the third reflection port 125 of the second wavelength division multiplexer 12. The wavelength division multiplexer 12, at this time, because the second filter element 124 (such as a filter) of the second wavelength division multiplexer 12 is designed to only allow the optical signal of the second wavelength λ2 to pass through, so the optical signal of the first wavelength λ1 The light signal will be reflected by the second filter element 124 and output from the second transmission port 123 (that is, to capture and drop the light signal of the first wavelength λ1). It is worth noting that the common port and the transmission port of the general wavelength division multiplexer focus on each other, and the optical signal ports of the transmission port and the reflection port are connected, but the second transmission port 123 of the second wavelength division multiplexer 12 of this embodiment The signal is connected to the second common port 121 and the third reflection port 125 , so the optical signal of the first wavelength λ1 entering the second wavelength division multiplexer 12 from the third reflection port 125 can be output from the second transmission port 123 .

In addition, the optical signals with wavelengths λ3, λ4... are reflected by the first filter element 114 and output from the first reflection port 112, and enter the optical filter 13 through the first communication port 131 of the optical filter 13, and the optical filter 13 It is designed to filter (isolate) the optical signal of the first wavelength λ1, therefore, the optical signal of the wavelength λ3, λ4... can pass through the filter 13 and output from the second communication port 132, and then pass through the second wavelength demultiplexer The second common port 121 of 12 enters the second wavelength division multiplexer 12, as mentioned above, the second filter element 124 of the second wavelength division multiplexer 12 is designed to only allow the optical signal of the second wavelength λ2 to pass through, Therefore, the optical signals with wavelengths λ3, λ4, . . . are reflected by the second filter element 124 and output from the second reflection port 122 .

30dB)，如此，第一波長λ1的光訊號不會進入第二波長分波多工器12干擾其它波長的光訊號。 Generally, the reflection isolation of a wavelength division multiplexer is about 15dB, and the higher one can be 15dB to 25dB. However, sometimes based on system design considerations, the isolation of optical signals of different wavelengths is required to be increased to more than 30dB. In the above transmission process, the optical signal of the first wavelength λ1 will pass through the first filter element 114 of the first wavelength division multiplexer 11 and output from the first transmission port 113. At this time, the optical signal of the wavelength λ1 can achieve reflection The isolation is about 15dB, but in the actual transmission process, part of the optical signal of the first wavelength λ1 will be reflected by the first filter element 114, and the optical signals of following wavelengths λ3, λ4... will be output from the first reflection port 112, and Then enter the optical filter 13, at this time, part of the optical signal of the first wavelength λ1 can be further filtered by the optical filter 13, so that the reflection isolation can be improved to not less than 30dB (

30dB), so that the optical signal of the first wavelength λ1 will not enter the second wavelength demultiplexer 12 to interfere with the optical signals of other wavelengths.

Please refer to Fig. 2 again, the optical signal of the second wavelength λ2 enters the second wavelength demultiplexer 12 by the second transmission port 123 of the second wavelength demultiplexer 12 through a single-core bidirectional optical fiber (that is, adding the Add second wavelength λ2 optical signal), as mentioned above, the second filter element 124 of the second wavelength demultiplexer 12 is designed to only allow the optical signal of the second wavelength λ2 to pass through, so the optical signal of the second wavelength λ2 will pass through The second filter element 124 is output by the second common port 121, and then passes through the optical filter 13 (the optical filter 13 is designed to filter the optical signal of the first wavelength λ1, so the optical signal of the second wavelength λ2 can pass through the optical filter 13 ), enter the first wavelength division multiplexer 11 from the first reflection port 112 of the first wavelength division multiplexer 11, and then be reflected by the first filter element 114 (the first filter element 114 is designed to only allow the first wavelength The optical signal of λ1 passes through) and is output from the first common port 111 .

In the structure shown in Fig. 2, the optical signal of the second wavelength λ2 added is a so-called backward (Backward) transmission form, which is transmitted back to the first wavelength division multiplexer 11 by the second wavelength division multiplexer 12 and Output from the first common port 111.

FIG. 3 is a structural diagram of an optical fiber network signal access module capable of improving reflection isolation in a second preferred embodiment of the present invention. In the optical fiber network signal access module 1 shown in FIG. 3 that can improve reflection isolation, its main structure and optical signal transmission mode are substantially the same as those of the first preferred embodiment shown in FIG. 2 above. The only difference is that in the embodiment shown in FIG. 3, the second common port 121 of the second wavelength division multiplexer 12 is reversed with the second reflection port 122, that is, the second communication port 132 of the optical filter 13 is communicated. In the second reflection port 122 of the second wavelength division multiplexer 12, the first communication port 131 of the optical filter 13 is also connected to the first reflection port 112 of the first wavelength division multiplexer 11, and the second wavelength division multiplexer The third reflection port 125 of the multiplexer 12 is also connected to the first transmission port 113 of the first wavelength division multiplexer 11 . In this way, the added optical signal of the second wavelength λ2 is in the form of so-called forward transmission and is output from the second common port 121 of the second wavelength division multiplexer 12 instead of returning to the first wavelength division multiplexer. 11.

FIG. 4 is a structural diagram of an optical fiber network signal access module capable of improving reflection isolation in a third preferred embodiment of the present invention. In the embodiment shown in Fig. 4, the optical fiber network signal access module 2 that can improve reflection isolation includes a first wavelength division multiplexer 21, a second wavelength division multiplexer 22, a The third wavelength demultiplexer 23 and a fourth wavelength demultiplexer 24, and the first wavelength demultiplexer 21, the second wavelength demultiplexer 22, the third wavelength demultiplexer 23 and the fourth wavelength demultiplexer The multiplexer 24 has the same components and functions.

Specifically, the first wavelength division multiplexer 21 includes a first common port 211, a first reflection port 212, a first transmission port 213 and a first filter element 214, wherein the first common port 211 is The reflection function of the first filter element 214 and the signal is connected to the first reflection port 212, and the first common port 211 is connected to the first transmission port 213 by the passing function of the first filter element 214; the second wavelength division multiplexer 22 includes a second common port 221, a second reflection port 222, a second transmission port 223, and a second filter element 224, and the second common port 221 is connected to the second filter element 224 by the reflection of the second filter element 224. Two reflection ports 222, the second common port 221 is connected to the second transmission port 223 through the second filter element 224, and the second reflection port 222 of the second wavelength division multiplexer 22 is connected to the first The first reflection port 212 of the wavelength division multiplexer 21; the third wavelength division multiplexer 23 includes a third common port 231, a third reflection port 232, a third transmission port 233 and a third filter element 234, The third common port 231 is connected to the third reflection port 232 by the reflection of the third filter element 234, and the third common port 231 is connected to the third transmission port 233 by the passage of the third filter element 234. And the third common port 231 of the third wavelength division multiplexer 23 is connected to the second common port 221 of the second wavelength division multiplexer 22; the fourth wavelength division multiplexer 24 includes a fourth common port 241, a The fourth reflection port 242, a fourth transmission port 243 and a fourth filter element 244, the fourth common port 241 is connected to the fourth reflection port 242 by the reflection of the fourth filter element 244, and the fourth common port 241 The signal is connected to the fourth transmission port 243 by the passage of the fourth filter element 244, and the fourth reflection port 242 of the fourth wavelength division multiplexer 24 is connected to the third reflection port 23 of the third wavelength division multiplexer 23. port 232. The transmission process of optical signals with different wavelengths is described in detail below.

As shown in Figure 4, after the optical signals of different wavelengths λ1, λ2, λ3, λ4... enter the first wavelength division multiplexer 21 through the first common port 211 of the first wavelength division multiplexer 21, due to the first The first filter element 214 of the wavelength division multiplexer 21 is designed to only allow the optical signal of the first wavelength λ1 to pass through, so the optical signal of the first wavelength λ1 passes through the first filter element 214 from the first common port 211 and then passes through the first filter element 214. A transmission port 213 outputs (that is, picks up and drops the optical signal of the first wavelength λ1), and the optical signals of other wavelengths λ2, λ3, λ4... cannot pass through the first filter element 214 and are reflected and output from the first reflection port 212 , and enter the second wavelength division multiplexer 22 from the second reflection port 222 of the second wavelength division multiplexer 22. Similarly, the second filter element 224 is designed to only allow the optical signal of the first wavelength λ1 to pass through, so the wavelengths λ2, λ3, λ4... The optical signal cannot pass through the second filter element 224 and is reflected and output from the second common port 221 , and then enters the third wavelength division multiplexer 23 through the third common port 231 of the third wavelength division multiplexer 23 . Then, the third filter element 234 is designed to only allow the optical signal of the second wavelength λ2 to pass through, so the optical signal of the second wavelength λ2 passes through the third filter element 234 from the third common port 231 and is output from the third transmission port 233 (That is to pick up and drop the optical signal of the second wavelength λ2), the optical signals of other wavelengths λ3, λ4... cannot pass through the third filter element 234 and are reflected and output from the third reflection port 232, and then transmitted by the fourth wavelength The fourth reflection port 242 of the wavelength division multiplexer 24 enters the fourth wavelength division multiplexer 24. Similarly, the fourth filter element 244 is designed to only allow the optical signal of the second wavelength λ2 to pass through, so the wavelengths λ3, λ4. The optical signal of .

Please refer to Fig. 4 again, the optical signal of the first wavelength λ1 enters the first wavelength division multiplexer 21 by the first transmission port 213 of the first wavelength division multiplexer 21, as mentioned above, the first filter element 214 is designed as Only the optical signal of the first wavelength λ1 can pass through, so the optical signal of the first wavelength λ1 passes through the first filter element 214 through the first transmission port 213 and is output by the first common port 211 (that is, adding the light of the first wavelength λ1 signal, transmitted backwards). In addition, the optical signal of the first wavelength λ1 enters the second wavelength division multiplexer 22 from the second transmission port 223 of the second wavelength division multiplexer 22. As mentioned above, the second filter element 224 is designed to only allow the second wavelength division multiplexer 22 The optical signal of a wavelength λ1 passes through, so the optical signal of the first wavelength λ1 passes through the second filter element 224 from the second transmission port 223 and is output to the third wavelength demultiplexer 23 by the second common port 221 (that is, adding the Add No. An optical signal of a wavelength λ1 is transmitted forward), at this time, since the third filter element 234 is designed to only allow the optical signal of the second wavelength λ2 to pass through, the optical signal of the first wavelength λ1 will follow the wavelengths λ3, λ4 The optical signal of ... is output to the fourth wavelength demultiplexer 24 by the third reflection port 232, and then the optical signal of the first wavelength λ1 is also designed to only allow the optical signal of the second wavelength λ2 because of the fourth filter element 244. The optical signals pass through and follow the optical signals of the wavelengths λ3, λ4, . . . and are output from the fourth common port 241 . The second reflection isolation of the first wavelength λ1 added from the second transmission port 223 by the third filter element 234 and the fourth filter element 244 is no less than 30 dB.

As can be seen from Fig. 4, the optical signal of the second wavelength λ2 enters the third wavelength division multiplexer 23 by the third transmission port 233 of the third wavelength division multiplexer 23, as mentioned above, the third filter element 234 is designed as Only the optical signal of the second wavelength λ2 can pass through, so the optical signal of the second wavelength λ2 passes through the third filter element 234 through the third transmission port 233 and is output from the third common port 231 to the second wavelength demultiplexer 22 for further processing. To the first wavelength division multiplexer 21, and output by the first common port 211 (that is, add the optical signal of the second wavelength λ2, and transmit it backward), the first filter element 214 and the second filter element 224 are respectively designed as only The optical signal of the first wavelength λ1 can pass through, and the isolation degree of the second reflection of the optical signal of the second wavelength λ2 added from the third transmission port 233 by the second filter element 224 and the first filter element 214 is not less than 30 dB.

In addition, the optical signal of the second wavelength λ2 enters the fourth wavelength division multiplexer 24 from the fourth transmission port 243 of the fourth wavelength division multiplexer 24. As mentioned above, the fourth filter element 244 is designed to only allow the fourth wavelength division multiplexer 24. The optical signal of the second wavelength λ2 passes through, so the optical signal of the second wavelength λ2 passes through the fourth filter element 244 through the fourth transmission port 243 and is output by the fourth common port 241 (that is, adding the optical signal of the second wavelength λ2, forward transmission).

It can be seen from the above that in the embodiment shown in Figure 4, the forward and backward transmission are integrated into one module, which can facilitate the flexible use of on-site construction personnel, perform wiring according to the needs of the site, and maximize the components Flexible use, thereby reducing the pressure on the types of component inventory. For example, the on-site construction personnel choose to connect to the appropriate access (Add/Drop) port after forward or backward transmission, and can also decide whether to add an optical circulator ( Circulator) integrates optical signals. In addition, in the embodiment shown in Figure 4, the optical signal of each wavelength (that is, the optical signal of the first wavelength λ1 and the optical signal of the second wavelength λ2) is reflected twice, so that the reflection isolation can be improved to 30dB above.

It can be seen from the above preferred embodiments that the optical fiber network signal access module proposed by the present invention can effectively improve the reflection isolation of optical signals and avoid the residual of optical signals of a certain wavelength Some of them interfere with optical signals of other wavelengths, which can effectively improve transmission efficiency. Furthermore, on-site construction personnel can carry out wiring according to on-site needs, which improves the flexibility of use.

The above descriptions are only preferred specific embodiments of the present model, and they are not intended to limit the present model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present model shall be included in the present model. within the scope of protection.

1,2: Optical fiber network signal access module that can improve reflection isolation 11: The first wavelength division multiplexer 111: the first common port 112: The first reflection port 113: The first transmission port 114: the first filter element 12: The second wavelength division multiplexer 121: Second common port 122: Second reflection port 123: Second transmission port 124: the second filter element 125: The third reflection port 13: Optical filter 131: The first communication port 132: Second communication port 21: The first wavelength division multiplexer 211: the first common port 212: The first reflection port 213: The first transmission port 214: the first filter element 22: The second wavelength division multiplexer 221: Second common port 222: Second reflection port 223: Second transmission port 224: Second filter element 23: The third wavelength division multiplexer 231: The third common port 232: The third reflection port 233: The third transmission port 234: The third filter element 24: The fourth wavelength division multiplexer 241: The fourth common port 242: The fourth reflection port 243: The fourth transmission port 244: The fourth filter element 9: Conventional optical fiber network signal access module 91: The first wavelength division multiplexer 92: second wavelength division multiplexer 911,921: common port 912,922: reflection port 913,923: Transmissive ports 914,924: filter element 93,94: Amplifier λ1, λ2, λ3, λ4: wavelength

Figure 1 is a structural diagram of a conventional optical fiber network signal access module; FIG. 2 is a structural diagram of an optical fiber network signal access module capable of improving reflection isolation in the first preferred embodiment of the present invention; Fig. 3 is a structural diagram of an optical fiber network signal access module capable of improving reflection isolation in a second preferred embodiment of the present invention; and FIG. 4 is a structural diagram of an optical fiber network signal access module capable of improving reflection isolation in a third preferred embodiment of the present invention.

1: Optical fiber network signal access module that can improve reflection isolation

11: The first wavelength division multiplexer

111: the first common port

112: The first reflection port

113: The first transmission port

114: the first filter element

12: The second wavelength division multiplexer

121: Second common port

122: Second reflection port

123: Second transmission port

124: the second filter element

125: The third reflection port

13: Optical filter

131: The first communication port

132: Second communication port

Claims (9)

An optical fiber network signal access module capable of improving reflection isolation, comprising: A first wavelength division multiplexer, including a first common port, a first reflection port, a first transmission port and a first filter element, the first common port is formed by the reflection of the first filter element The signal is connected to the first reflection port, and the first common port is connected to the first transmission port by the passing function of the first filter element, and the first filter element can pass the optical signal of the first wavelength; A second wavelength division multiplexer, including a second common port, a second reflection port, a third reflection port, a second transmission port and a second filter element, the second common port is based on the second The signal is connected to the second reflection port by the reflection function of the filter element, the signal is connected to the second transmission port by the pass function of the second filter element, and the signal is connected to the second transmission port by the second reflection port. The signal is connected to the second transmission port due to the reflection of the filter element, and the third reflection port is connected to the first transmission port. The second filter element can pass the light signal of the second wavelength, which is different from the second wavelength. the first wavelength; and An optical filter, including a first communication port and a second communication port, the first communication port is connected to the first reflection port, the second communication port is connected to the second common port and the second reflection port One of the ports, wherein the optical filter can isolate the optical signal of the first wavelength. The optical fiber network signal access module capable of improving reflection isolation as described in claim 1, wherein the second communication port is connected to the second common port. The optical fiber network signal access module capable of improving reflection isolation as described in claim 1, wherein the second communication port is connected to the second reflection port. The optical fiber network signal access module capable of improving reflection isolation as described in Claim 1, wherein the isolation degree of the optical filter for isolating the optical signal of the first wavelength is not less than 30 dB. An optical fiber network signal access module capable of improving reflection isolation, comprising: A first wavelength division multiplexer, including a first common port, a first reflection port, a first transmission port and a first filter element, the first common port is formed by the reflection of the first filter element The signal is connected to the first reflection port, and the first common port is connected to the first transmission port by the passing function of the first filter element; A second wavelength division multiplexer, including a second common port, a second reflection port, a second transmission port and a second filter element, the second common port is realized by the reflection of the second filter element The signal is connected to the second reflection port, the second common port is connected to the second transmission port by the passing function of the second filter element, and the second reflection port is connected to the first reflection port; A third wavelength division multiplexer, including a third common port, a third reflection port, a third transmission port and a third filter element, the third common port is realized by the reflection of the third filter element The signal is connected to the third reflection port, the third common port is connected to the third transmission port by the passing function of the third filter element, and the third common port is connected to the second common port; and A fourth wavelength division multiplexer, including a fourth common port, a fourth reflection port, a fourth transmission port and a fourth filter element, the fourth common port is realized by the reflection of the fourth filter element The signal is connected to the fourth reflection port, the fourth common port is connected to the fourth transmission port by the passage of the fourth filter element, and the fourth reflection port is connected to the third reflection port. The optical fiber network signal access module capable of improving reflection isolation as described in claim 5, wherein the optical signal of the first wavelength added from the second transmission port passes through the second filter element and is filtered by the third filter The reflection of the element and the fourth filter element is output from the fourth common port. The optical fiber network signal access module capable of improving reflection isolation as described in claim 6, wherein the isolation of the optical signal of the first wavelength reflected by the third filter element and the fourth filter element is not less than 30 dB. The optical fiber network signal access module capable of improving reflection isolation as described in claim 5, wherein the optical signal of the second wavelength added from the third transmission port passes through the third filter element and passes through the second filter The reflection of the element and the first filter element is output from the first common port. The optical fiber network signal access module capable of improving reflection isolation as described in claim 8, wherein the isolation of the second wavelength optical signal reflected by the second filter element and the first filter element is not less than 30 dB.

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