JP7598972B2 - Bidirectional Wavelength Access System - Google Patents

Description

The present invention relates to optical network components, and in particular to bidirectional wavelength access systems.

With the emergence of wavelength division multiplexing (WDM) networks in the fronthaul of 5G optical networks, low-cost WDM optical networks are attracting market attention.

Therefore, for those skilled in the art, an important issue is how to design devices that can improve the node access performance of 5G mobile WDM network transmission.

In consideration of this, the present invention provides a bidirectional wavelength access system that can be used to solve the above technical problems.

An embodiment of the present invention provides a bidirectional wavelength access system including a first bidirectional wavelength access device. The first bidirectional wavelength access device includes a first optical circulator and a first demultiplexing filter group. The first optical circulator includes a first port, a second port, and a third port. The first demultiplexing filter group is connected to a first main axis optical cable, and the first demultiplexing filter group guides a first incident light transmitted through the first main axis optical cable to the first port of the first optical circulator, and guides a first return light received from the third port of the first optical circulator to the first main axis optical cable. Here, both the first incident light and the first return light have a first wavelength.

As a result, the bidirectional wavelength access system proposed by the embodiment of the present invention can effectively reduce the cost and time required to deploy an optical network configuration.

1 is a schematic diagram of a bidirectional wavelength access system according to a first embodiment of the present invention; FIG. 2 is a schematic diagram of a bidirectional wavelength access system according to a second embodiment of the present invention; FIG. 11 is a schematic diagram of a bidirectional wavelength access system according to a third embodiment of the present invention. FIG. 11 is a schematic diagram of a bidirectional wavelength access system according to a fourth embodiment of the present invention. FIG. 13 is a schematic diagram of a bidirectional wavelength access system according to a fifth embodiment of the present invention. FIG. 13 is a diagram illustrating an application scenario according to the sixth embodiment of the present invention. FIG. 13 is a diagram illustrating an application scenario according to the seventh embodiment of the present invention. FIG. 23 is a diagram illustrating an application scenario according to the eighth embodiment of the present invention.

Referring to FIG. 1, it is a schematic diagram of a bidirectional wavelength access system according to a first embodiment of the present invention. In FIG. 1, the bidirectional wavelength access system 10 includes a first bidirectional wavelength access device 11, which includes a first optical circulator 111 and a first demultiplexing filter group 112. The first optical circulator 111 includes a first port 111a, a second port 111b, and a third port 111c. The first demultiplexing filter group 112 is connected to a first main axis optical cable 199, and the first demultiplexing filter group 112 guides the first incident light IL1 transmitted through the first main axis optical cable 199 to the first port 111a of the first optical circulator 111, and guides the first return light OL1 received from the third port 111c of the first optical circulator 111 to the first main axis optical cable 199. Here, the first incident light IL1 and the first return light OL1 both have a first wavelength (hereinafter referred to as WL1).

In the first embodiment, the second port 111b of the first optical circulator 111 is used to output the first incident light IL1 from the first port 111a of the first optical circulator 111 and to guide the first return light OL1 received from the first external device E1 to the third port 111c of the first optical circulator 111.

In the first embodiment, the second port 111b of the first optical circulator 111 is connected to a first external device E1 that provides a first return light OL1 via a single-core optical cable FI1.

In different embodiments, the first external device E1 may include, for example, an optical circulator E11, a receiver Rx1, and a transmitter Tx1, and the optical circulator E11 may receive, for example, a first incident light IL1 from the second port 111b of the first optical circulator 111 via a second port of the optical circulator E11, and may further emit the first incident light IL1 to the receiver Rx1 via a third port of the optical circulator E11. The optical circulator E11 may also receive, for example, a first return light OL1 from the transmitter Tx1 via a first port of the optical circulator E11, and may forward the first return light OL1 to the second port of the optical circulator E11 via the first port of the optical circulator E11. The second port of the optical circulator E11 can then transmit the first return light OL1 to the second port 111b of the first optical circulator 111 via the single-core optical cable FI1.

In one embodiment, the first external device E1 may include only a receiver Rx1 and a transmitter Tx1, and the optical circulator E11 may be connected between the first optical circulator 111 and the first external device E1 as an independent device, for example, but is not limited to this.

In some embodiments, the first external device E1 can be implemented as various types of communication devices/nodes, such as, but not limited to, various types of base stations.

In FIG. 1, the first demultiplexing filter group 112 includes a single demultiplexing filter 112a, and has an included angle AN1 between the light-guiding surface S1 of the demultiplexing filter 112a and the transmission direction D1 of the main ray ML transmitted within the first main axis optical cable 199, the included angle AN1 being 135 degrees. As a result, when the first incident light IL1 in the main ray ML is incident on the light-guiding surface S1, the light-guiding surface S1 can guide the first incident light IL1 to the first port 111a of the first optical circulator 111.

Furthermore, when the light-guiding surface S1 of the demultiplexing filter 112a receives the first return light OL1 from the third port 111c of the first optical circulator 111, the light-guiding surface S1 guides the first return light OL1 to the first main axis optical cable 199, and the first return light OL1 can be transmitted within the first main axis optical cable 199.

In the first embodiment, the demultiplexing filter 112a of the first demultiplexing filter group 112 guides only the first incident light IL1 having the second wavelength WL2 of the main light ML transmitted through the first main axis optical cable 199 to the first port 111a of the first optical circulator 111, and bypasses the other incident light of the main light ML that does not have the second wavelength WL2. In FIG. 1, the light guiding surface S1 of the demultiplexing filter 112a guides only the first incident light IL1 having the second wavelength WL2 of the main light ML to the first port 111a of the first optical circulator 111, and the other incident light of the main light ML that does not have the second wavelength WL2 passes directly through the demultiplexing filter 112a, but is not limited to this. From another perspective, it can be understood that the demultiplexing filter 112a of the first demultiplexing filter group 112 acts only on light having the second wavelength WL2 (e.g., the first incident light IL1 and the first return light OL1).

In the first embodiment, the first incident light IL1 and the first return light OL1 may have opposite transmission directions in the first main axis optical cable 199. In FIG. 1, the transmission direction of the first incident light IL1 may be, for example, the same direction as the transmission direction D1 of the main light ML, and the transmission direction D2 of the first return light OL1 may be, for example, the opposite direction to the transmission direction D1. In the embodiment of the present invention, since the first incident light IL1 and the first return light OL1 have opposite transmission directions in the first main axis optical cable 199, this application scenario can be called "backward return", but is not limited thereto.

In other embodiments, the included angle AN1 may be appropriately adjusted to correspond to the relative positions between the first branching filter group 112, the first main axis optical cable 199, and the first optical circulator 111, and is not limited to the aspect shown in FIG. 1.

2, which is a schematic diagram of a bidirectional wavelength access system according to a second embodiment of the present invention. In FIG. 2, the bidirectional wavelength access system 20 includes a first bidirectional wavelength access device 21 having a first optical circulator 111 and a first demultiplexing filter group 212. The first optical circulator 111 includes a first port 111a, a second port 111b, and a third port 111c. The first demultiplexing filter group 212 is connected to the first main axis optical cable 199, where the first demultiplexing filter group 212 guides the first incident light IL1 transmitted through the first main axis optical cable 199 to the first port 111a of the first optical circulator 111, and guides the first return light OL1 received from the third port 111c of the first optical circulator 111 to the first main axis optical cable 199, where the first incident light IL1 and the first return light OL1 both have the second wavelength WL2.

The second embodiment differs from FIG. 1 in that the first branching filter group 212 of the second embodiment further includes a branching filter 212b in addition to the branching filter 212a, and the operation method of the branching filter 212a is the same as that of the branching filter 112a of FIG. 1. In the second embodiment, the included angle AN between the branching filters 212a and 212b may be 90 degrees. More specifically, the branching filter 212b may have a light-guiding surface S2, and the included angle AN' between the light-guiding surfaces S1 and S2 may be 270 degrees, but is not limited to this.

In FIG. 2, there is an included angle AN2 between the light-guiding surface S2 of the demultiplexing filter 212b and the transmission direction D1 of the principal ray ML, and the included angle AN2 is 135 degrees.

In the second embodiment, the light guiding surface S1 can be used to guide the first incident light IL1 transmitted through the first main axis optical cable 199 to the first port 111a of the first optical circulator 111. The light guiding surface S2 can be used to receive the first return light OL1 from the third port 111c of the first optical circulator 111, and to guide the first return light OL1 to the first main axis optical cable 199 and transmit the first return light OL1 within the first main axis optical cable 199.

In the second embodiment, the demultiplexing filter 212a of the first demultiplexing filter group 212 guides only the first incident light IL1 having the second wavelength WL2 of the main light ML transmitted through the first main axis optical cable 199 to the first port 111a of the first optical circulator 111, and bypasses the other incident light of the main light ML that does not have the second wavelength WL2. In FIG. 2, the light guiding surface S1 of the demultiplexing filter 212a guides only the first incident light IL1 having the second wavelength WL2 of the main light ML to the first port 111a of the first optical circulator 111, and the other incident light of the main light ML that does not have the second wavelength WL2 passes directly through the demultiplexing filter 212a, but is not limited thereto. From another perspective, it can be understood that the demultiplexing filter 112a of the first demultiplexing filter group 212 acts only on light having the second wavelength WL2 (e.g., the first incident light IL1 and the first return light OL1).

The demultiplexing filter 212b of the first demultiplexing filter group 212 may be designed to act only on light having the second wavelength WL2. In other words, the demultiplexing filter 212b may directly pass other light rays of the principal light ML that do not have the second wavelength WL2, but is not limited to this.

In the second embodiment, the first incident light IL1 and the first return light OL1 may have the same transmission direction in the first main axis optical cable 199. In FIG. 2, the transmission direction of the first incident light IL1 may be, for example, the same direction as the transmission direction D1 of the main light ML, and the transmission direction of the first return light OL1 may be, for example, the same direction as the transmission direction D1. In the embodiment of the present invention, since the first incident light IL1 and the first return light OL1 have the same transmission direction in the first main axis optical cable 199, this application scenario can be called "forward return", but is not limited thereto.

In other embodiments, the illustrated angles can be appropriately adjusted according to the relative positions between the first branching filter group 212, the first main axis optical cable 199, and the first optical circulator 111, and are not limited to the aspect shown in FIG. 2.

Please refer to Fig. 3, which is a schematic diagram of a bidirectional wavelength access system according to a third embodiment of the present invention. In Fig. 3, the bidirectional wavelength access system 30 may further include a second bidirectional wavelength access device 31 in addition to the first bidirectional wavelength access device 11 in Fig. 1, where the related details of the first bidirectional wavelength access device 11 can be referred to the related description of Fig. 1 and will not be repeated here.

In the third embodiment, the second bidirectional wavelength access device 31 includes a second optical circulator 311 and a second demultiplexing filter group 312. The second optical circulator 311 includes a first port 311a, a second port 311b, and a third port 311c. The second demultiplexing filter group 312 is connected to the first main axis optical cable 199, where the second demultiplexing filter group 312 guides the second incident light IL2 transmitted through the first main axis optical cable 199 to the first port 311a of the second optical circulator 311, and guides the second return light OL2 received from the third port 311c of the second optical circulator 311 to the first main axis optical cable 199, where both the second incident light IL2 and the second return light OL2 have a second wavelength (hereinafter referred to as WL2).

In the third embodiment, the second port 311b of the second optical circulator 311 is used to output the second incident light IL2 from the first port 311a of the second optical circulator 311 and to guide the second return light OL2 received from the second external device E2 to the third port 311c of the second optical circulator 311.

In the third embodiment, the second port 311b of the second optical circulator 311 is connected to a second external device E2 that provides a second return light OL2 via a single-core optical cable FI2.

In a different embodiment, the second external device E2 may include, for example, an optical circulator E21, a receiver Rx2, and a transmitter Tx2, and the optical circulator E21 may receive, for example, a second incident light IL2 from the second port 311b of the second optical circulator 311 via a second port of the optical circulator E21, and emit the second incident light IL2 to the receiver Rx2 via a third port of the optical circulator E21. Also, the optical circulator E21 may receive, for example, a second return light OL2 from the transmitter Tx2 via a first port of the optical circulator E21, and transfer the second return light OL2 to the second port of the optical circulator E21 via the first port of the optical circulator E21. The second port of the optical circulator E21 can then transmit the second return light OL2 to the second port 311b of the second optical circulator 311 via the single-core optical cable FI2.

In one embodiment, the second external device E2 may include only a receiver Rx2 and a transmitter Tx2, and the optical circulator E21 may be connected, for example, between the second optical circulator 311 and the second external device E2, but is not limited to this.

In some embodiments, the second external device E2 can be implemented as a variety of communication devices/nodes, such as, but not limited to, a variety of base stations.

In FIG. 3, the second demultiplexing filter group 312 includes a single demultiplexing filter 312a, and may have an included angle of 135 degrees between the light guiding surface of the single demultiplexing filter 312a and the transmission direction D1 of the main light ML transmitted within the first main axis optical cable 199. As a result, when the second incident light IL2 of the main light ML is incident on the light guiding surface of the demultiplexing filter 312a, the light guiding surface of the demultiplexing filter 312a can guide the second incident light IL2 to the first port 311a of the second optical circulator 311.

In addition, when the light guiding surface of the branching filter 312a receives the second return light OL2 from the third port 311c of the second optical circulator 311, the light guiding surface of the branching filter 312a can guide the second return light OL2 into the main axis optical cable 199 so that the second return light OL2 is transmitted through the first main axis optical cable 199.

In the third embodiment, the demultiplexing filter 312a of the second demultiplexing filter group 312 guides only the second incident light IL2 having the second wavelength WL2 of the main light ML transmitted through the first main axis optical cable 199 to the first port 311a of the second optical circulator 311, and bypasses the other incident light of the main light ML that does not have the second wavelength WL2. In FIG. 3, the light guiding surface of the demultiplexing filter 312a guides only the second incident light IL2 having the second wavelength WL2 of the main light ML to the first port 311a of the second optical circulator 311, and the other incident light of the main light ML that does not have the second wavelength WL2 passes directly through the demultiplexing filter 312a, but is not limited to this. From another perspective, the demultiplexing filter 312a of the second demultiplexing filter group 312 can be understood as acting only on light having the second wavelength WL2 (e.g., the second incident light IL2 and the second return light OL2).

In the third embodiment, the second incident light IL2 and the second return light OL2 may have opposite transmission directions within the first main axis optical cable 199. In FIG. 3, the transmission direction of the second incident light IL2 may be, for example, the same direction as the transmission direction D1 of the main light ML, and the transmission direction D2 of the second return light OL2 may be, for example, the opposite direction to the transmission direction D1. In other words, the second bidirectional wavelength access device 31 can also be understood to be used in a "backward return" scenario.

3, the first demultiplexing filter group 112 receives the main light ML transmitted through the first main axis optical cable 199 before the second demultiplexing filter group 312. Since the first demultiplexing filter group 112 has already guided the first incident light IL1 having the first wavelength WL1 to the first port 111a of the first optical circulator 111, the main light ML received by the second demultiplexing filter group 312 does not include any light having the first wavelength WL1. From another perspective, the light diverted by the first demultiplexing filter group 112 includes light having the second wavelength WL2 (e.g., the second incident light IL2).

In addition, since the structure of the second bidirectional wavelength access device 31 in FIG. 3 is substantially the same as the structure of the first bidirectional wavelength access device 11, the bidirectional wavelength access system 30 can also be understood to include two first bidirectional wavelength access devices 11. These two first bidirectional wavelength access devices 11 can sequentially guide light rays having corresponding wavelengths among the main light rays ML transmitted in the first main axis optical cable 199 to corresponding optical circulators, but are not limited to this.

In some embodiments, the second bidirectional wavelength access device 31 and the first bidirectional wavelength access device 11 of FIG. 3 may be implemented as separate devices or may be integrated into the same particular bidirectional wavelength access device.

In other embodiments, the bidirectional wavelength access system 30 may include more first bidirectional wavelength access devices 11 and/or second bidirectional wavelength access devices 31, each of which may operate according to the methods mentioned in the associated description of Figures 1 and 3.

Referring to FIG. 4, it is a schematic diagram of a bidirectional wavelength access system according to a fourth embodiment of the present invention. In FIG. 4, the bidirectional wavelength access system 40 may further include a second bidirectional wavelength access device 41 in addition to the first bidirectional wavelength access device 21 shown in FIG. 2, where the relevant details of the first bidirectional wavelength access device 21 can refer to the relevant description of FIG. 2 and will not be repeated here.

In the fourth embodiment, the second bidirectional wavelength access device 41 includes a second optical circulator 411 and a second demultiplexing filter group 412. The second optical circulator 411 includes a first port 411a, a second port 411b, and a third port 411c. The second demultiplexing filter group 412 is connected to the first main axis optical cable 199, and the second demultiplexing filter group 412 guides the second incident light IL2 transmitted through the first main axis optical cable 199 to the first port 411a of the second optical circulator 411, and guides the second return light OL2 received from the third port 411c of the second optical circulator 411 to the first main axis optical cable 199, where both the second incident light IL2 and the second return light OL2 have a second wavelength WL2.

In the fourth embodiment, the second port 411b of the second optical circulator 411 is used to output the second incident light IL2 from the first port 411a of the second optical circulator 411 and to guide the second return light OL2 received from the second external device E2 to the third port 411c of the second optical circulator 411.

In the fourth embodiment, the second port 411b of the second optical circulator 411 is connected to a second external device E2 that provides a second return light OL2 via a single-core optical cable FI2.

In a different embodiment, the second external device E2 may include, for example, an optical circulator E21, a receiver Rx2, and a transmitter Tx2, and the optical circulator E21 receives, for example, a second incident light IL2 from the second port 411b of the second optical circulator 411 via a second port of the optical circulator E21, and emits the second incident light IL2 to the receiver Rx2 via a third port of the optical circulator E21. Also, the optical circulator E21 receives, for example, a second return light OL2 from the receiving transmitter Tx2 via a first port of the optical circulator E21, and transfers the second return light OL2 to the second port of the optical circulator E21 via the first port of the optical circulator E21. The second port of the optical circulator E21 can then transmit the second return light OL2 to the second port 411b of the second optical circulator 411 via the single-core cable FI2.

In one embodiment, the second external device E2 may include only a receiver Rx2 and a transmitter Tx2, and the optical circulator E21 may be connected as an independent device between the second optical circulator 411 and the second external device E2, for example, but is not limited to this.

In some embodiments, the second external device E2 can be implemented as a variety of communication devices/nodes, such as, but not limited to, a variety of base stations.

In FIG. 4, the second branching filter group 412 includes branching filters 412a and 412b, and the relevant angle settings of the branching filters 412a and 412b can refer to the settings of the branching filters 212a and 212b in FIG. 2.

In the fourth embodiment, the light guiding surface of the demultiplexing filter 412a can be used to guide the second incident light IL2 transmitted through the first main axis optical cable 199 to the first port 411a of the second optical circulator 411. The light guiding surface of the demultiplexing filter 412b can be used to receive the second return light OL2 from the third port 411c of the second optical circulator 411, and to guide the second return light OL2 to the first main axis optical cable 199 and transmit the second return light OL2 within the first main axis optical cable 199.

In the fourth embodiment, the demultiplexing filter 412a of the second demultiplexing filter group 412 guides only the first incident light IL1 having the second wavelength WL2 of the main light ML transmitted through the first main axis optical cable 199 to the first port 411a of the second optical circulator 411, and bypasses the other incident light of the main light ML that does not have the second wavelength WL2. In FIG. 4, the light guiding surface of the demultiplexing filter 412a guides only the second incident light IL2 having the second wavelength WL2 of the main light ML to the first port 411a of the second optical circulator 411, and the other incident light of the main light ML that does not have the second wavelength WL2 passes directly through the demultiplexing filter 412a, but is not limited thereto. From another perspective, it can be understood that the branching filter 412a of the second branching filter group 412 acts only on light having the second wavelength WL2 (e.g., the second incident light IL2).

The demultiplexing filter 412b of the second demultiplexing filter group 412 may be designed to act only on light having the second wavelength WL2 (e.g., the second return light OL2). In other words, the demultiplexing filter 412b may directly pass other light rays of the main light ML that do not have the second wavelength WL2, but is not limited to this.

In the fourth embodiment, the second incident light IL2 and the second return light OL2 may have the same transmission direction within the first main axis optical cable 199. In FIG. 4, the transmission direction of the second incident light IL2 is, for example, the same direction as the transmission direction D1 of the main light ML, and the transmission direction of the second return light OL2 can also be the same direction as the transmission direction D1. In other words, the second bidirectional wavelength access device 41 can also be understood to be used in a "forward-return" scenario.

In FIG. 4, the first demultiplexing filter group 212 receives the main light ML transmitted through the first main axis optical cable 199 before the second demultiplexing filter group 412. Since the first demultiplexing filter group 212 has already guided the first incident light IL1 having the first wavelength WL1 to the first port 111a of the first optical circulator 111, the main light ML received by the second demultiplexing filter group 312 does not include any light having the first wavelength WL1. From another perspective, the light diverted by the first demultiplexing filter group 112 includes light having the second wavelength WL2 (e.g., the second incident light IL2).

In addition, since the structure of the second bidirectional wavelength access device 41 in FIG. 4 is substantially the same as the structure of the first bidirectional wavelength access device 21, the bidirectional wavelength access system 30 can also be understood to include two first bidirectional wavelength access devices 21. These two first bidirectional wavelength access devices 21 can sequentially guide light rays having corresponding wavelengths among the main light rays ML transmitted within the first main axis optical cable 199 to corresponding optical circulators, but are not limited to this.

In some embodiments, the second bidirectional wavelength access device 41 and the first bidirectional wavelength access device 21 of FIG. 4 may be implemented as separate devices or may be integrated into the same particular bidirectional wavelength access device.

In other embodiments, the bidirectional wavelength access system 40 may include more first bidirectional wavelength access devices 21 and/or second bidirectional wavelength access devices 41, each of which may operate according to the methods mentioned in the associated description of Figures 2 and 4.

Referring to FIG. 5, it is a schematic diagram of a bidirectional wavelength access system according to a fifth embodiment of the present invention. In FIG. 5, the bidirectional wavelength access system 50 includes a first bidirectional wavelength access device 11 and a third bidirectional wavelength access device 51, and the details of the first bidirectional wavelength access device 11 can be referred to the relevant description of FIG. 1 and will not be repeated here.

In the fifth embodiment, the third bidirectional wavelength access device 51 includes a third optical circulator 511 and a third demultiplexing filter group 512. The third optical circulator 511 includes a first port 511a, a second port 511b, and a third port 511c. The third demultiplexing filter group 512 is connected to the second main axis optical cable 599, and the third demultiplexing filter group 512 guides the third incident light IL3 transmitted through the second main axis optical cable 599 to the first port 511a of the third optical circulator 511, and guides the third return light OL3 from the third port 511c of the third optical circulator 511 to the second main axis optical cable 599, where the third incident light IL3 and the third return light OL3 both have a third wavelength (hereinafter referred to as WL3).

In this embodiment, the structure of the third bidirectional wavelength access device 51 is substantially identical to the structure of the first bidirectional wavelength access device 11, but the first bidirectional wavelength access device 11 is connected to the first main axis optical cable 199, and the third bidirectional wavelength access device 51 is connected to the second main axis optical cable 599. Therefore, for details of the operation method of the third bidirectional wavelength access device 51, please refer to the relevant description of FIG. 1 and will not be repeated here.

In the fifth embodiment, the output end of the first main axis optical cable 199 can be connected to the input end of the second main axis optical cable 599 via an optical fiber jumper JL, thereby realizing a function similar to that of the configuration shown in FIG. 3. More specifically, the configuration of FIG. 3 can be understood as different wavelength access devices connected in series internally, and the configuration of FIG. 5 can be understood as different wavelength access devices connected in series externally. As can be seen from this, the configuration of the embodiment of the present invention has a certain degree of freedom in configuration.

Referring to FIG. 6, it is a diagram showing an application scenario according to the sixth embodiment of the present invention. In FIG. 6, the configuration shown in the left half is a schematic diagram of an existing optical network configuration 610, and the configuration shown in the right half is a schematic diagram of an optical network configuration 620 after applying the bidirectional wavelength access system of this embodiment.

In the optical network configuration 61, when a telecommunication station end wants to provide an optical signal to a user end, it is necessary to multiplex optical signals of different wavelengths through a wavelength division multiplexer (WDM) 611 and transmit the multiplexed optical signal to a WDM 612 (which can be installed in an optical chemical junction box or machine room end) corresponding to the user end. When the WDM 612 at the user end receives the multiplexed optical signal from the WDM 611, the WDM 612 can demultiplex the multiplexed optical signal and transmit optical signals having different wavelengths to the user end devices A, B, C, and D through the corresponding bidirectional two-core optical fibers. As can be seen from this, when there are N user end devices at the user end, it is necessary to use N*2 optical fibers to realize the optical network configuration 610.

In comparison, in an optical network configuration 620 (corresponding to a "backward return" scenario) that applies the bidirectional wavelength access system of an embodiment of the present invention, a single bidirectional wavelength access device is needed to forward a light beam (optical signal) of a particular wavelength to a corresponding user end device via a single-core optical fiber. Therefore, if there are N user end devices at the user end, only N optical fibers are needed to realize the optical network configuration 620.

It should be understood that in the optical network configuration 620, the demultiplexing filters of the first bidirectional wavelength access device 11 and/or the second bidirectional wavelength access device 31 corresponding to different user end devices can be used to guide light rays having corresponding wavelengths. For example, assuming that the user end device A corresponds to a certain wavelength 1, the demultiplexing filter in the first bidirectional wavelength access device 11 corresponding to the user end device A can be used to guide the light rays having wavelength 1 in the first main axis optical cable 199. Also, assuming that the user end device B corresponds to a certain wavelength 2, the demultiplexing filter in the first bidirectional wavelength access device 11 corresponding to the user end device B can be used to guide the light rays having wavelength 2 in the first main axis optical cable 199. Furthermore, assuming that the user end devices C and D correspond to wavelengths 3 and 4, respectively, the demultiplexing filters in the first bidirectional wavelength access device 11 and the third bidirectional wavelength access device 31 of the user end devices C and D can be used to guide the light rays having wavelengths 3 and 4 in the first main axis optical cable 199, respectively.

As can be seen, compared to the existing optical network configuration 610, the optical network configuration 620 that applies the bidirectional wavelength access system of an embodiment of the present invention can save half the number of optical fibers, thereby effectively reducing the cost and time required to deploy the optical network configuration.

Referring to FIG. 7, it is a diagram showing an application scenario according to the seventh embodiment of the present invention. In FIG. 7, the illustrated network configuration diagram 710 corresponds to, for example, a "forward return" scenario. As can be seen from FIG. 7, by using only one bidirectional wavelength access device, a light beam (optical signal) having a certain wavelength can be guided to a corresponding base station end through a single-core optical fiber. Therefore, when there are N base station ends, the optical network configuration 710 can be realized at the user end by using only N optical fibers. As can be seen from this, compared with the existing optical network configuration, the optical network configuration 710 applying the bidirectional wavelength access system of the embodiment of the present invention can save half the number of optical fibers, so that the cost and time of deploying the optical network configuration can be effectively reduced.

Referring to FIG. 8, it is a diagram showing an application scenario according to an eighth embodiment of the present invention. In FIG. 8, the configuration shown in the upper half is a schematic diagram of an existing optical network configuration 810, and the configuration shown in the lower half is a schematic diagram of an optical network configuration 820 after applying the bidirectional wavelength access system according to an embodiment of the present invention.

In the optical network configuration 810, if a baseband unit (BBU) and/or a distribution unit (DU) is to provide optical signals to four base stations 811-814, it needs to multiplex optical signals having different wavelengths through a corresponding WDM, and then transmit the multiplexed optical signal to the WDM corresponding to the base station. The WDM corresponding to the base station can then demultiplex the multiplexed optical signal and transmit the optical signals having different wavelengths to the base stations 811-814 through the corresponding bidirectional two-core optical fiber. Therefore, in the optical network configuration 810, the WDM corresponding to the base station needs to transmit the optical signals corresponding to different wavelengths to the base stations 811-814 through the eight-core optical cable.

In comparison, in an optical network configuration 820 employing the bidirectional wavelength access system of an embodiment of the present invention (which corresponds to a "backward return" scenario), a light beam (optical signal) having a particular wavelength can be guided to a corresponding base station via a single-core optical fiber using only one bidirectional wavelength access device, so that at the base station end, the optical network configuration 820 can be realized using only four optical fibers.

It should be understood that in the optical network configuration 820, demultiplexing filters in the first bidirectional wavelength access device 11 corresponding to different base stations can be used to direct light rays having corresponding wavelengths. For example, assuming that the base station 811 corresponds to a certain wavelength 1, a demultiplexing filter in the first bidirectional wavelength access device 11 corresponding to the base station 811 can be used to direct light rays having wavelength 1 in the first main axis optical cable 199. Also, assuming that the base station 812 corresponds to a certain wavelength 2, a demultiplexing filter in the first bidirectional wavelength access device 11 corresponding to the base station 812 can be used to direct light rays having wavelength 2 in the first main axis optical cable 199.

As can be seen, compared to the existing optical network configuration 810, the optical network configuration 820 that applies the bidirectional wavelength access system of an embodiment of the present invention can save half the number of optical fibers, thereby effectively reducing the cost and time required to deploy the optical network configuration.

In summary, the embodiment of the present invention has at least the following features: (1) Solves the problem of low-cost WDM optical network distributed multi-node access service. (2) Can achieve bidirectional bandwidth barrier-free intercommunication with a single optical fiber by any optical transmission method, saving more than half the number of optical fibers for transmission, and effectively reducing the cost and timeliness of laying new optical cables. In addition, the embodiment of the present invention can utilize the existing optical network to deploy and reuse optical components, so that in addition to saving costs and increasing operational benefits, when adding a service port, it can solve the problem of temporary fiber core shortage in the field while realizing plug and play without affecting the original network and equipment.

In addition, the configuration of the embodiment of the present invention uses optical passive components, so there is no need for a power supply, and it has the advantage of being easy to install, maintain, and operate. Furthermore, the configuration of the embodiment of the present invention can be installed in an outdoor activity junction box or optical fiber junction box, which is convenient to access at each node.

From another perspective, the object of the present invention is to provide a set of externally mounted single optical fiber bidirectional wavelength access devices. In a related application scenario, maintenance and operation personnel can directly implement the configuration of an embodiment of the present invention at an access node of a WDM optical network, thereby instantly acquiring downstream wavelengths and preserving upstream wavelengths.

Although the present invention has been disclosed in the above embodiments, the present invention is not limited thereto, and a person skilled in the art may make some changes or modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention should be defined by the appended claims.

The bidirectional wavelength access system of the present invention can be applied to the deployment of 5G optical networks.

10, 20, 30, 40, 50: bidirectional wavelength access system 11, 21: first bidirectional wavelength access device 111: first optical circulator 112, 212: first demultiplexing filter group 112a, 112b, 212a, 212b, 312a, 412a, 412b: demultiplexing filter 111a, 311a, 411a, 511a: first port 111b, 311b, 411b, 511b: second port 111c, 311c, 411c, 511c: third port 199: first main axis optical cable 31: second bidirectional wavelength access device 311, 411: second optical circulator 312, 412: second demultiplexing filter group 51: third bidirectional wavelength access device 511: Third optical circulator 512: Third demultiplexing filter group 599: Second main axis optical cable 610, 620, 710, 810, 820: Optical network configuration 611, 612: WDM
811 to 814: Base stations A, B, C, D: User end devices IL1: First incident light IL2: Second incident light IL3: Third incident light OL1: First return light OL2: Second return light OL3: Third return light E1: First external device E2: Second external device FI1, FI2: Single-core optical cable E11, E21: Optical circulator Rx1, Rx2: Receiver Tx1, Tx2: Transmitter D1, D2: Transmission direction AN1, AN2, AN, AN': Included angle S1, S2: Light-guiding surface ML: Main ray

Claims (14)

a first optical circulator comprising a first port, a second port, and a third port;
a first demultiplexing filter group connected to a first main axis optical cable, the first demultiplexing filter group guiding a first incident light transmitted through the first main axis optical cable to the first port of the first optical circulator and guiding a first return light received from the third port of the first optical circulator to the first main axis optical cable, the first incident light and the first return light both having a first wavelength;
A bidirectional wavelength access system comprising a first bidirectional wavelength access device comprising: the second port of the first optical circulator is used to output the first incident light from the first port of the first optical circulator and to guide the first return light received from a first external device to the third port of the first optical circulator;
The bidirectional wavelength access system according to claim 1 . the second port of the first optical circulator is connected via a single-core optical cable to a first external device that provides the first return light;
The bidirectional wavelength access system according to claim 1 . The first branching filter group includes a single branching filter, and has an included angle between a light guiding surface of the single branching filter and a transmission direction of a principal ray transmitted through the first main axis optical cable, the included angle being 135 degrees.
The bidirectional wavelength access system according to claim 1 . the first incoming light and the first returning light have opposite directions of transmission in the first main axis optical cable;
The bidirectional wavelength access system according to claim 4. the first branching filter group includes a first branching filter and a second branching filter, and has a first included angle between a first light guiding surface of the first branching filter and a transmission direction of a principal ray transmitted within the first main axis optical cable, and has a second included angle between a second light guiding surface of the second branching filter and the transmission direction of the principal ray, the first included angle being 135 degrees, the second included angle being 135 degrees, and the included angle between the first branching filter and the second branching filter being 90 degrees.
The bidirectional wavelength access system according to claim 1 . the first incident light and the first return light have the same transmission direction in the first main axis optical cable;
The bidirectional wavelength access system according to claim 6. the included angle between the first light-directing surface and the second light-directing surface is 270 degrees;
The bidirectional wavelength access system according to claim 6. the first branching filter group acts only on light having the first wavelength;
The bidirectional wavelength access system according to claim 1 . the first demultiplexing filter group guides only the first incident light having the first wavelength among the principal rays transmitted through the first main axis optical cable to the first port of the first optical circulator, and bypasses other incident lights among the principal rays that do not have the first wavelength.
The bidirectional wavelength access system according to claim 1 . a second optical circulator comprising a first port, a second port, and a third port;
a second demultiplexing filter group connected to the first main axis optical cable, the second demultiplexing filter group guiding a second incident light transmitted through the first main axis optical cable to the first port of the second optical circulator and guiding a second return light received from the third port of the second optical circulator to the first main axis optical cable, the second incident light and the second return light both having a second wavelength;
The bidirectional wavelength access system of claim 1 , further comprising a second bidirectional wavelength access device comprising: the first branching filter group receives a main ray transmitted through the first main axis optical cable prior to the second branching filter group;
The bidirectional wavelength access system according to claim 11. the first bidirectional wavelength access device and the second bidirectional wavelength access device are integrated into a specific bidirectional wavelength access device;
The bidirectional wavelength access system according to claim 11. a third optical circulator including a first port, a second port, and a third port;
a third demultiplexing filter group connected to a second main axis optical cable, the third demultiplexing filter group guiding a third incident light transmitted through the second main axis optical cable to the first port of the third optical circulator and guiding a third return light received from the third port of the third optical circulator to the second main axis optical cable, the third incident light and the third return light both having a third wavelength, and an output end of the first main axis optical cable being connected to an input end of the second main axis optical cable via an optical fiber jumper;
The bidirectional wavelength access system according to claim 1 , further comprising a third bidirectional wavelength access device comprising:

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