WO2024105874A1

WO2024105874A1 - Optical transmission system, optical splitter unit, and optical transmission method

Info

Publication number: WO2024105874A1
Application number: PCT/JP2022/042823
Authority: WO
Inventors: 勝久田口; 聖成川; 誉人桐原; 亜弥子岩城; 和秀中島; 隆松井; 千里深井; 悠途寒河江
Original assignee: 日本電信電話株式会社
Priority date: 2022-11-18
Filing date: 2022-11-18
Publication date: 2024-05-23

Abstract

The purpose of the present invention is to provide an optical transmission system that can secure fairness of optical power between regions to be irradiated with and safety of the optical power and that can achieve design freedom in irradiation time, low cost, and power saving.　An optical transmission system according to the present invention comprises: an optical transmission path 26 through which light L1 is propagated from a light source 11 by means of a bundle optical fiber 36 formed by bundling a plurality of single optical fibers (single core optical fibers 51a); an optical splitter unit 12b that splits the light propagated through the optical transmission path 26 toward a plurality of output ports at a given split ratio; a control unit 15b that adjusts the split ratio for the optical splitter unit 12b; and paths 14 through which the light is propagated from the output ports of the optical splitter unit 12a to regions to be irradiated with.

Description

Optical transmission system, optical branching section, and optical transmission method

This disclosure relates to an optical transmission system that uses an optical fiber bundle consisting of multiple optical fibers as an optical transmission path, an optical branching unit provided therein, and a method for doing so.

There is an increasing demand for systems that use ultraviolet light to sterilize and inactivate viruses for the purpose of preventing infectious diseases. There are three main categories of such systems. In this specification, the term "sterilization, etc." refers to sterilization and inactivation of viruses.
(I) Mobile sterilization robot The product of Non-Patent Document 1 is an autonomous mobile robot that irradiates ultraviolet light. The robot can irradiate ultraviolet light while moving around a room in a building such as a hospital room, thereby automatically sterilizing a wide area without human intervention.
(II) Freestanding Air Purifier The product in Non-Patent Document 2 is a device that is installed on the ceiling or a predetermined location in a room and circulates the air in the room while sterilizing, etc. This device does not directly irradiate ultraviolet light and has no effect on the human body, so it is possible to sterilize, etc. with a high degree of safety.
(III) Portable sterilization device The product of Non-Patent Document 3 is a portable device equipped with an ultraviolet light source. A user can take the device to a desired area and irradiate ultraviolet light. Therefore, the device can be used in various places.

However, the devices described in the non-patent literature have the following problems.
(1) Economic Efficiency The product of Non-Patent Document 1 irradiates high-power ultraviolet light, so the device is large-scale and expensive. Therefore, the product of Non-Patent Document 1 has a problem that it is difficult to realize an economical system.
(2) Versatility With the product of Non-Patent Document 1, the location where ultraviolet light can be irradiated is limited to a location where a robot can move/enter, making it difficult to irradiate narrow or deep spaces with ultraviolet light.
The product of Non-Patent Document 2 sterilizes the circulated indoor air, and therefore cannot irradiate the location where sterilization is desired with ultraviolet light directly.
The product of Non-Patent Document 3 cannot irradiate ultraviolet light onto, for example, narrow pipes or areas where people cannot enter.
As described above, the products described in non-patent documents have a problem in that they lack versatility in terms of being able to irradiate ultraviolet light at any location.
(3) Operability The product of Non-Patent Document 3 is portable and can irradiate ultraviolet light in various locations. However, in order to obtain sufficient sterilization effects at the target location, the user is required to have skills and knowledge, and there are problems with operability.

To address these issues, an ultraviolet light irradiation system 300 using optical fibers as shown in FIG. 1 can be considered. In this ultraviolet light irradiation system, ultraviolet light is transmitted from the ultraviolet light source unit 11a using a thin and easily bendable optical fiber, and the ultraviolet light output from the tip of the optical fiber 14 is irradiated to the irradiation target area AR where pinpoint sterilization or the like is desired. Since ultraviolet light can be irradiated to any location simply by moving the irradiation unit 13 at the tip of the optical fiber 14, the versatility of the above issue (2) can be resolved. In addition, since there is no need to move or set up the ultraviolet light source, and no skill or knowledge is required of the user, the operability of the above issue (3) can also be resolved. Furthermore, by providing an optical distribution unit 12 such as an optical splitter in the optical transmission path 16 and configuring the system as a P-MP (Point to Multipoint) such as FTTH (Fiber To The Home), a single light source can be shared and multiple locations can be sterilized or the like. Therefore, the economics of the above issue (1) can also be resolved.

Furthermore, in an ultraviolet light irradiation system, it has been proposed to use an inexpensive LED (Light-Emitting Diode) as a light source instead of a laser, which has a high coupling efficiency to an optical fiber, to reduce system costs. Here, "coupling efficiency" means the ratio of the power input to the optical fiber (optically coupled to the optical fiber core) to the output power of the light source.
The problem with this proposal is shown in Figure 2. Since the light-emitting surface of an LED is larger than that of a laser, even if you try to couple the light output from the LED to a single-core optical fiber, the core area in the cross section is narrow, and most of the light is not coupled, resulting in low coupling efficiency (Figure 2(A)). This is the same even if you narrow the light output from the LED using an optical system such as a lens (Figure 2(B)). In other words, when an LED is used as a light source, there is a problem that most of the output power of the light source cannot be effectively used.
This problem is not limited to optical transmission systems that transmit ultraviolet light, but is a common problem to optical transmission systems that transmit infrared light or visible light.

Here, if light is coupled to multiple cores present in the cross section, such as in a multi-core optical fiber (MCF) or a bundled optical fiber consisting of multiple single-core optical fibers, the coupling efficiency can be improved and the waste of output power from the light source can be reduced (Figure 2 (C)).

Fig. 3 is a diagram for explaining the configuration of an optical transmission system using a general bundle optical fiber. The configuration of the optical transmission system includes the PP (Point to Point) configuration shown in Fig. 3(A), and the P-MP (Point to Multi Point) configuration shown in Fig. 3(B) to (D). As described above, the optical transmission system using the bundle optical fiber has the effect of reducing the waste of the output power of the light source, but each of the configurations in Fig. 3 also has the following problems.
(a) There is a power deviation between the irradiation units 13, and it is difficult to eliminate the unfairness between the irradiation target areas.
(b) There is a power deviation between the irradiation units 13, making it difficult to ensure the safety of the irradiated optical power to the human body, etc.
(c) It is not possible to weight the power of the light irradiated from the irradiating unit 13, and therefore the degree of freedom in designing the irradiation time is low.
(d) It is difficult to reduce costs.
(e) Difficulty in reducing power consumption

In the P2P configuration of FIG. 3(A), light L1 from the light source unit 11 incident on one end T1 of the bundle optical fiber 36 is propagated through the bundle optical fiber 36, and the other end T2 of the bundle optical fiber 36 serves as an irradiation unit to irradiate the irradiation target area with light L2. In this configuration, one optical transmission system supplies light to only one irradiation target area, so if there are multiple irradiation target areas, multiple optical transmission systems are required. This results in the above issues (d) and (e).

The P-MP configuration in FIG. 3(B) is a configuration in which each single optical fiber 51a constituting the bundle optical fiber 36 is separated at the other end T2 of the bundle optical fiber 36 and wired to the irradiation target area as a path 14. In the P-MP configuration in FIG. 3(B), light L1 from the light source unit 11 incident on one end T1 of the bundle optical fiber 36 is propagated through the bundle optical fiber 36 and the path 14, and light L2 is irradiated from the irradiation unit 13 to the irradiation target area. In this configuration, light can be supplied to multiple irradiation target areas. However, although light L1 from the light source unit 11 is irradiated to one end (joint portion) of the bundle optical fiber 36, the illuminance is not uniform on the irradiation surface (light spot) (there is a power deviation). Specifically, the illuminance is high near the center of the light spot and low around the light spot. For this reason, there is a power deviation in the light propagating through each single-core optical fiber 51a of the bundle optical fiber 36 and each path 14, which causes the above problems (a) and (b).

The P-MP configuration of FIG. 3(C) is a configuration in which an optical branching unit 12 that evenly branches the light propagating through the bundle optical fiber 36 to each path 14 is disposed at the other end T2 of the bundle optical fiber 36, and each path 14 is wired to the irradiation target area. In particular, in the P-MP configuration of FIG. 3(C), the path 14 is a bundle optical fiber 37. In the P-MP configuration of FIG. 3(C), light L1 from the light source unit 11 that is incident on one end T1 of the bundle optical fiber 36 propagates through the bundle optical fiber 36 and the path 14, and light L2 is irradiated from the irradiation unit 13 to the irradiation target area. In this configuration, light can be supplied to multiple irradiation target areas. However, as described above, the light L1 propagating through each single-core optical fiber 51a of the bundle optical fiber 36 has a power deviation, and since this is equally branched to each path 14 by the optical branching unit 12, there is a power deviation in the light propagating through each path 14, which causes the above problems (a) and (b). Furthermore, since it has an optical branching section 12 that branches equally, the above problem (c) also exists. And since the path 14 is a bundle optical fiber 37, the cost is high, and the above problem (d) also exists.

The P-MP configuration of FIG. 3(D) is a configuration in which an optical branching unit 12 that evenly branches the light propagating through the bundle optical fiber 36 to each path 14 is disposed at the other end T2 of the bundle optical fiber 36, and each path 14 is wired to the irradiation target area. In particular, in the P-MP configuration of FIG. 3(D), the path 14 is a single (not bundled) optical fiber 55. In the P-MP configuration of FIG. 3(D), light L1 from the light source unit 11 that is incident on one end T1 of the bundle optical fiber 36 propagates through the bundle optical fiber 36 and the path 14, and light L2 is irradiated from the irradiation unit 13 to the irradiation target area. In this configuration, light can be supplied to multiple irradiation target areas. However, as described above, the light L1 propagating through each single-core optical fiber 51a of the bundle optical fiber 36 has a power deviation, and since this is equally branched to each path 14 by the optical branching unit 12, there is a power deviation in the light propagating through each path 14, which causes the above problems (a) and (b). Furthermore, since it is equipped with an optical branching section 12 that branches equally, the above problem (c) also occurs.

The present invention aims to provide an optical transmission system, optical branching unit, and optical transmission method that can achieve fairness of optical power between irradiation target areas, guarantee the safety of optical power, freedom in designing irradiation time, low cost, and power saving in order to solve the above-mentioned problems.

In order to achieve the above objective, the optical transmission system according to the present invention has a P-MP configuration using bundled optical fibers, and uses an unequal branching optical branching section to branch light from the bundled optical fibers to each direction.

Specifically, the optical transmission system according to the present invention comprises:
an optical transmission path that propagates light from a light source unit using an optical fiber bundle in which a plurality of single optical fibers are bundled;
an optical branching unit that branches the light propagated through the optical transmission line into a plurality of output ports at an arbitrary branching ratio;
a control unit that adjusts the branching ratio of the optical branching unit;
a path for propagating the light from each of the output ports of the optical branching unit to each of the irradiation target areas;
Equipped with.

Further, the optical transmission method according to the present invention comprises:
Propagating light from a light source unit using an optical bundle formed by bundling a plurality of single optical fibers as an optical transmission path;
In an optical branching unit, the light propagated through the optical transmission line is branched into a plurality of output ports at an arbitrary branching ratio;
Propagating the light from each of the output ports of the optical branching unit to each of the irradiation target areas; and adjusting the branching ratio of the optical branching unit so that the power of the light irradiated to the irradiation target area is a target.

The optical branching unit does not branch equally, but the branching ratio can be adjusted for each output port. Therefore, by adjusting the branching ratio of the optical branching unit while considering the fairness of issue (a), the safety of issue (b), and the weighting of issue (c), these issues can be resolved. Furthermore, because it is a P-MP configuration, it is also possible to resolve issue (d) of low cost and issue (e) of power saving. Furthermore, even if the situation of the irradiation target area changes after the branching ratio is set (the required optical power changes, the number of irradiation target areas changes, etc.), the branching ratio can be easily readjusted from the control unit.

Therefore, the present invention can provide an optical transmission system and an optical transmission method that can achieve fairness of optical power among irradiation target areas, guarantee of safety of optical power, freedom in designing irradiation time, low cost, and power saving.

The paths may all be single optical fibers, or may be bundled optical fibers consisting of multiple single optical fibers.

For example, the goal is to uniformly distribute the power of the light irradiated onto the irradiation target area,
The control unit may adjust the branching ratio so as to approach the target.

Also, the objective is to set the power of the light irradiated to the irradiation target area to a required value for each of the irradiation target areas,
The control unit may adjust the branching ratio so as to approach the target.

The optical transmission system according to the present invention comprises:
an optical system that couples the light from the light source unit to each of the plurality of optical fibers bundled in the bundle optical fiber of the optical transmission path at a predetermined coupling ratio;
A control unit that adjusts the binding rate to more closely approach the target;
It is preferable that the device further comprises:
After adjusting the power of the light irradiated to each irradiation target area by the branching ratio of the optical branching section, the power of the light irradiated to each irradiation target area can be fine-tuned by the coupling ratio of the optical system.

The above inventions can be combined as much as possible.

The present invention can provide an optical transmission system, optical branching unit, and optical transmission method that can achieve fairness of optical power among irradiation target areas, guarantee of safety of optical power, freedom in designing irradiation time, low cost, and power saving.

FIG. 1 is a diagram illustrating a problem to be solved by the present invention. FIG. 1 is a diagram illustrating a problem to be solved by the present invention. FIG. 1 is a diagram illustrating a problem to be solved by the present invention. 1 is a diagram illustrating an optical transmission system according to the present invention; 2 is a diagram illustrating a configuration of an optical branching unit included in the optical transmission system according to the present invention; FIG. 2 is a diagram illustrating a configuration of an optical branching unit included in the optical transmission system according to the present invention; FIG. 1A to 1C are diagrams illustrating the effect of an optical branching unit included in an optical transmission system according to the present invention. 1 is a diagram illustrating an optical transmission system according to the present invention; 1 is a diagram illustrating an optical transmission system according to the present invention; 4A and 4B are diagrams illustrating a structure of a light separating unit. 1 is a diagram illustrating an optical transmission system according to the present invention; FIG. 1 is a diagram illustrating an optical system of an optical transmission system according to the present invention. 5A and 5B are diagrams illustrating adjustment of a coupling state performed by an optical system of the optical transmission system according to the present invention. 1 is a diagram illustrating an optical transmission method according to the present invention;

The following describes an embodiment of the present invention with reference to the attached drawings. The embodiment described below is an example of the present invention, and the present invention is not limited to the following embodiment. Note that components with the same reference numerals in this specification and drawings are mutually identical.

(Embodiment 1)
FIG. 4 is a diagram illustrating an optical transmission system according to the present embodiment.
an optical transmission path 26 that propagates light L1 from a light source unit 11 using a bundle optical fiber 36 in which a plurality of single optical fibers (single-core optical fibers 51 a) are bundled;
an optical branching unit 12b that branches the light propagated through the optical transmission line 26 into a plurality of output ports at an arbitrary branching ratio;
a control unit 15b that adjusts the branching ratio of the optical branching unit 12b;
a path 14 for propagating the light from each of the output ports of the optical branching unit 12b to each of the irradiation target areas;
Equipped with.
An irradiation unit 13 is disposed at the tip of the path 14, and irradiates the irradiation target area with light L2. Note that, in this embodiment, an optical system 11c is provided to couple the light L1 from the light source unit 11 to one end of the bundle optical fiber 36, but depending on the size of the spot shape of the light L1 output from the light source unit 11 and the diameter of one end of the bundle optical fiber 36, the optical system 11c may be unnecessary.

FIG. 4A shows an optical transmission system in which the paths 14 are all optical bundles 37 each consisting of a plurality of single optical fibers bundled together.
FIG. 4B shows an optical transmission system in which all of the paths 14 are a single optical fiber 55 .
It should be noted that "single optical fiber" means that it is not an optical fiber bundle.

The optical transmission system of FIG. 4 has a feature that a goal is to equalize the power of the light L2 irradiated to the irradiation target area, and the control unit 15b adjusts the branching ratio so as to approach the goal.
4, taking into consideration the power deviation of the light propagating through each optical fiber bundled in the bundle optical fiber 36 and the transmission distance of the path 14, the control unit 15b adjusts the branching ratio of the optical branching unit 12b so that the power of the light L2 irradiated from the irradiation unit 13 becomes uniform, as compared to the optical transmission systems of Figures 3C and 3D. Here, "so that it becomes uniform" means that the branching ratio adjusted by the control unit 15b makes the power of the light L2 irradiated from the irradiation unit 13 more uniform than the current branching ratio of the optical branching unit 12b.
In addition, an illuminometer that measures the power of light L2 may be arranged in each irradiation target area or irradiation unit 13 so that the control unit 15b can adjust the branching ratio of the optical branching unit 12b so that the power of the light L2 irradiated from the irradiation unit 13 is uniform.

5 is a diagram for explaining the structure of the optical branching unit 12b when the optical transmission system has the configuration as shown in FIG.
a number of multiplexers 133 equal to the number (N) of output ports 132, each of which outputs the light to a corresponding output port 132;
an optical switch 133, the number of which is equal to the number (I) of single optical fibers (single-core optical fibers 51 a) bundled into the bundle optical fiber 36, for outputting the light from the corresponding single optical fiber to one of the multiplexers 133 or to a terminal unit 135;
has.
The optical branching unit 12 b further includes a core separation adapter 121 , an optical fiber 123 , and an optical fiber 125 .

The core separation adapter 121 dismantles and separates the multiple (I) single-core optical fibers 51a bundled into the bundle optical fiber 36. The optical switch 131 is a 1×(N+1) optical switch with one input port and N+1 output ports. Each single-core optical fiber (51a-1 to 51a-I) dismantled by the core separation adapter 121 is connected to the input port of the optical switch 131. N of the output ports of each optical switch 131 are connected to the corresponding input port of the multiplexer 133 via the optical fiber 123. In addition, a termination unit 135 is connected to one of the output ports of each optical switch 131 (the one not connected to the optical fiber 123). The output port of each multiplexer 133 is connected to the output port 132 via the optical fiber 125. A route 14 is connected to each output port 132.

Light from the light source unit 11 propagates through each single-core optical fiber 51a of the bundle optical fiber 36 as a unit. Each single-core optical fiber 51a is separated by the core separation adapter 121, and each light propagating through the single-core optical fiber 51a is input to the optical switch 131. The control unit 15b controls the switching of each optical switch 131, and the light is output to one of the optical fibers 123 or to the terminal unit 135. The light output to the terminal unit 135 is terminated there. The light output to the optical fiber 123 is multiplexed with light from other optical switches 123 in the multiplexing unit 133. The light multiplexed in each multiplexing unit 133 is output to the path 14 via the optical fiber 125.

6 is a diagram for explaining the structure of an optical branching unit 12b when the optical transmission system has the configuration as shown in FIG. 4(A). In contrast to the optical branching unit 12b in FIG. 5, the optical branching unit 12b in FIG.
Between the multiplexer 133 and the output port (in this configuration, the core separation adapter 139), there is further provided a demultiplexer 134 that combines the light output by the multiplexer 133 to all the single optical fibers (single-core optical fibers 55) bundled in the bundle optical fiber 37 of the path 14.
The number of single-core optical fibers 55 bundled into one bundle optical fiber 37 is J.

The light propagating through each optical fiber 125 is split into J single-core optical fibers 55 by the splitter 134. The J single-core optical fibers 55 are bundled by the core separation adapter 139 to become the bundle optical fiber 37. In other words, the light propagating through each optical fiber 125 propagates as a single light through each single-core optical fiber 55 of the bundle optical fiber 37, which is the path 14, to the irradiation unit 13.

Here, the effect of providing a multiplexer 133 and a demultiplexer 134 in the optical branching unit 12b in FIG. 6 will be explained with reference to FIG. 7. FIG. 7(A) is a diagram illustrating a cross section of a bundle optical fiber 37 in the case where the multiplexer 133 and the demultiplexer 134 are not provided and the optical fibers 123 corresponding to each path 14 are bundled as a single-core optical fiber 55. FIG. 7(B) is a diagram illustrating a cross section of the bundle optical fiber 37 in the configuration of the optical branching unit 12b in FIG. 6.

7A, when the multiplexer 133 and the demultiplexer 134 are not provided, there will be single-core optical fibers 55 to which the light from the optical switch 131 is coupled and single-core optical fibers 55 to which the light from the optical switch 131 is not coupled. In this way, a difference occurs between the presence and absence of light in the single-core optical fibers 55, and illuminance unevenness occurs in the light L2 emitted from the irradiation unit 13.
7B, in the case where a multiplexer 133 and a demultiplexer 134 are provided, the multiplexer 133 multiplexes the light from each optical switch 131 into one, and the demultiplexer 134 distributes the light to the J single-core optical fibers 55 of the bundle optical fiber 37 so that the power is uniform. Since the power deviation between the single-core optical fibers 55 is eliminated, illuminance unevenness is unlikely to occur in the light L2 emitted from the irradiation unit 13.

Note that the color of the core of the optical fiber through which light is propagating in Figure 7(A) is darker than the color of the core of the optical fiber through which light is propagating in Figure 7(B). The color of the core represents the strength of the light power. In Figure 7(A), the light is biased and concentrated in a specific single-core optical fiber 55, so the power of the light propagating through that optical fiber is strong. On the other hand, in Figure 7(B), the light is evenly distributed and leveled out to all single-core optical fibers 55, so the power of the light propagating through the optical fiber is weaker than the optical power in Figure 7(A).

As explained in Fig. 5 and Fig. 6, the branching ratio of the optical branching unit 12b is adjusted by the control unit 15b issuing a switching instruction to each optical switch 131 as to which output port the light from the single-core optical fiber 51a should be output to. In the optical transmission system of Fig. 4, the control unit 15b outputs a switching instruction to the optical switch 131 so that the power of the light L2 irradiated from the irradiation unit 13 is equal in all cases.

(Embodiment 2)
Fig. 8 is a diagram for explaining the optical transmission system of this embodiment. The configuration of this optical transmission system is the same as that of the optical transmission system explained in Fig. 4. However, this optical transmission system is characterized in that it aims to make the power of the light L2 irradiated to the irradiation target area a required value for each of the irradiation target areas, and the control unit 15b adjusts the branching ratio so as to approach the target.

The power of the light L2 required by each irradiation target area may differ. For this reason, in the optical transmission system, it is preferable that the branching ratio of the optical branching unit 12b is adjusted so that the power of the light L2 required by each irradiation target area is irradiated to each irradiation target area.
8, the branching ratio of the optical branching unit 12b is adjusted so that the power of the light L2 irradiated from the irradiation unit 13 satisfies the requirements of each irradiation target area (so that the power of the light L2 to each irradiation target area approaches the requirements of each irradiation target area more than in the optical transmission systems of FIGS. 3C and 3D), taking into consideration the power deviation of the light propagating through each optical fiber bundled in the bundle optical fiber 36 and the transmission distance of the path 14. In addition, when the light to be transmitted is ultraviolet light, it is necessary to adjust the branching ratio of the optical branching unit 12b so that the power of the ultraviolet light in the irradiation target area does not exceed the safety standard.

The structure described in Fig. 5 and Fig. 6 can be applied to the optical branching unit 12b of this embodiment. However, in the description of Fig. 5 and Fig. 6, it was described that "the branching ratio of the optical branching unit 12b is adjusted so that the power of the light L2 irradiated from the irradiation unit 13 is uniform." However, in this embodiment, the branching ratio of the optical branching unit 12b is adjusted so that the power of the light L2 irradiated from the irradiation unit 13 satisfies the requirements of each irradiation target area. Here, "so that the power of the light L2 satisfies the requirements of each irradiation target area" means that the power of the light L2 irradiated from the irradiation unit 13 is closer to the requirements of each irradiation target area with the branching ratio adjusted by the control unit 15b than with the current branching ratio of the optical branching unit 12b.
As in the description of embodiment 1, in the optical transmission system of this embodiment, an illuminometer that measures the power of light L2 may be arranged in each irradiation target area or irradiation unit 13 so that the control unit 15b can adjust the branching ratio of the optical branching unit 12b.

(Embodiment 3)
FIG. 9 is a diagram illustrating an optical transmission system according to the present embodiment.
an optical transmission path 26 that propagates light L1 from a light source unit 11 using a bundle optical fiber 36 in which a plurality of single optical fibers (single-core optical fibers 51 a) are bundled;
a light separating unit 12d for separating the single optical fibers (single-core optical fibers 51a) bundled into the bundle optical fiber 36, and having a shutter for transmitting or blocking light propagating through each of the single optical fibers (single-core optical fibers 51a);
A control unit 15b that instructs each of the shutters of the light separating unit 12d to transmit or block light;
a path 14 for propagating the light from each of the single optical fibers (single-core optical fibers 51 a) separated by the light separation unit 12 d to each of the irradiation target areas;
Equipped with.
An irradiation unit 13 is disposed at the tip of the path 14, and irradiates the irradiation target area with light L2. Note that, in this embodiment as well, there is an optical system 11c that couples the light L1 from the light source unit 11 to one end of the bundle optical fiber 36, but depending on the size of the spot shape of the light L1 output by the light source unit 11 and the diameter of one end of the bundle optical fiber 36, the optical system 11c may be unnecessary.

Path 14 is a single optical fiber 55, but the single-core optical fiber 51a separated by the optical separation unit 12d may be used as path 14 as is.

In the optical transmission system of Fig. 9, the control unit 15b can set whether or not to irradiate the light L2 for each irradiation target area. In other words, in the optical transmission system of Fig. 9, the control unit 15b adjusts each shutter of the light separation unit 12d so that the light L2 irradiated from the irradiation unit 13 meets the requirement of the irradiation target area (request for light irradiation/no need for light irradiation).
In addition, a communication path may be provided to transmit requests from each irradiation target area or the irradiation unit 13 to the control unit 15b so that the control unit 15b can grasp the requests of the irradiation target areas.

FIG. 10 is a diagram explaining the structure of the optical separation unit 12d. The optical branching unit 12b includes a core separation adapter 121, a shutter 141, and an output port 132.

The shutters 141 transmit/block light according to instructions from the control unit 15b. A shutter 141 is placed on each of the single-core optical fibers (51a-1 to 51a-I) disassembled by the core separation adapter 121. In other words, there are I shutters 141. Each single-core optical fiber (51a-1 to 51a-I) on which the shutter 141 is placed is connected to an output port 132. A path 14 of a single optical fiber 55 is connected to each output port 132. Note that, as mentioned above, if the single-core optical fiber 51a is used as the path 14 as is, the output port 132 is not necessary, and the single-core optical fiber 51a is wired to each irradiation target area.

Light from the light source unit 11 propagates through each single-core optical fiber 51a of the bundle optical fiber 36 as a unit. The single-core optical fibers 51a are separated by the core separation adapter 121, and each light that has propagated through the single-core optical fiber 51a is input to the shutter 141. The control unit 15b controls the transmission/blocking of each shutter 141, and the light input to a shutter 141 set to transmission is output to the output port 132 and output to the path 14. On the other hand, the light input to a shutter 141 set to blocking is terminated there.

(Embodiment 4)
Fig. 11 is a diagram for explaining the optical transmission system of this embodiment. The configuration of the optical transmission system in Fig. 11(A) is the optical transmission system explained in Fig. 4, the configuration of the optical transmission system in Fig. 11(B) is the optical transmission system explained in Fig. 8, and the configuration of the optical transmission system in Fig. 11(C) is the optical transmission system explained in Fig. 9 to which a control unit 15 is added. In other words, this optical transmission system is a configuration similar to that of the optical transmission systems explained in Figs. 4, 8, and 9.
an optical system 11c that couples light L1 from the light source unit 11 to each of a plurality of optical fibers bundled in the optical fiber bundle 36 of the optical transmission line 26 at a predetermined coupling ratio;
A control unit 15 that adjusts the binding rate so as to further approach the target;
The present invention is characterized by further comprising:
In addition, the control unit 15 of the optical transmission system in Figure 11 (C) aims to equalize the power of light L2 irradiated to the irradiation target area requesting light irradiation, or to set the power of light L2 irradiated to the irradiation target area requesting light irradiation to the required value for each of the irradiation target areas.

11 includes an optical system 11c that changes the coupling ratio between the light source unit 11 and each core of the bundle optical fiber 36 by the control unit 15. The control unit 15b adjusts the coupling ratio of the optical system 11c as follows, taking into account the branching ratio of the optical branching unit 12b, the power deviation between the ports of the optical branching unit 12b (the optical branching unit 12b may not branch light according to the set branching ratio due to manufacturing errors, etc.), and the transmission distance of the path 14.
11A, the coupling rate of the optical system 11c is adjusted so that the power of the light L2 irradiated from the irradiating unit 13 becomes equal to that of the light transmission system of FIG.
(b) In the case of the optical transmission system of FIG. 11(B), the coupling rate of the optical system 11c is adjusted so that the power of the light L2 irradiated from the irradiating unit 13 satisfies the requirements of each irradiation target area, as compared to the optical transmission system of FIG.
(c) In the case of the optical transmission system of Figure 11 (C), the coupling rate of the optical system 11c is adjusted so that the power of the light L2 irradiated from the irradiation unit 13 to the irradiation target area requesting light irradiation is equal or so as to meet the requirements of each irradiation target area, as compared to the optical transmission system of Figure 9.

In other words, the optical transmission system of FIG. 11 is characterized in that after the power of the light L2 irradiated from each irradiation unit 13 is adjusted to a desired value by the branching ratio of the optical branching unit 12b, or after the optical fiber is separated by the optical separation unit 12d, the power of the light L2 irradiated from each irradiation unit 13 is fine-tuned by the coupling rate of the optical system 11c so that it approaches the desired value even more.

FIG. 12 is a diagram illustrating the optical system 11c.
The optical system 11c is
The coupling state in which the light L1 is incident on each core (the core of the bundled single-core optical fiber 51 a) of the bundle optical fiber 36 is arbitrarily adjusted, and as the adjustment of the coupling state, the size Lc of the spot shape of the light L1 is adjusted between the diameter of a circle that includes all of the multiple cores and the diameter of a circle that includes only one of the multiple cores.

The optical system 11c adjusts the size of the spot shape of the light L1 from the light source unit 11 and irradiates one end T1 of the bundle optical fiber 36. The size of the spot shape of the light L1 at one end T1 of the bundle optical fiber 36 is indicated by "Lc". The optical system 11c adjusts the coupling rate of the light coupled to the core of each single-core optical fiber 51a by adjusting the size Lc of the spot shape. Here, in this specification, "coupling rate" means the ratio between the total power of the light L1 output by the light source unit 11 and the power of the light L1 coupled to each single-core optical fiber 51a at one end T1 of the bundle optical fiber 36.

For example, the optical system 11c adjusts the coupling rate to eliminate the power deviation of the light L1 at one end T1 and couple the light L1 fairly to the cores of each single-core optical fiber 51a (realizing power fairness), to utilize the power deviation of the light L1 at one end T1 to couple the light L1 to the cores of each single-core optical fiber 51a so as to satisfy the power required by the irradiation target area (realizing requirement fairness), or to reduce the light L1 that is not coupled to the cores of the single-core optical fibers 51a (reducing waste and saving power).

Figure 13 is a diagram explaining the adjustment of the coupling state performed by the optical system 11c. All of Figures 13 show the state of the size Lc of the spot shape of the light L1 at one end T1 of the bundle optical fiber 36.

Figures 13(A) to 13(C) are diagrams explaining how the optical system 11c adjusts the coupling state (adjusts the size Lc of the spot shape) while aligning the optical axis of the light L1 with the central axis of the bundle optical fiber 36.

For example, if the optical system 11c widens the size Lc of the spot shape as shown in FIG. 13(A), uniform power can be coupled to each single-core optical fiber 51a, except for the single-core optical fiber 51a on the outer periphery of the bundle optical fiber 36. In other words, if the optical system 11c adjusts the size Lc of the spot shape as shown in FIG. 13(A), the uniformity and fairness of the power of the light irradiated to the irradiation target area can be improved. Also, although there is waste in the power of the light L1 output by the light source unit 11, by widening the size Lc of the spot shape beyond the diameter of the bundle optical fiber 36, uniform power can be coupled even to the single-core optical fiber 51a on the outer periphery.

For example, if the optical system 11c narrows the size Lc of the spot shape to an extent that only one single-core optical fiber 51a is included, as shown in FIG. 13(B), the light L1 output by the light source unit 11 can be concentrated on the core of the single-core optical fiber 51a, and strong power light can be supplied to the irradiation target area corresponding to the single-core optical fiber 51a. For example, if the light L1 is ultraviolet light, the inactivation of the irradiation target area can be completed in a short period of time.

In addition, to obtain a compromise between the effects described in Figures 13(A) and (B), the optical system 11c can narrow the size Lc of the spot shape to an extent that includes multiple single-core optical fibers 51a located near the center of the bundle optical fiber 36, as shown in Figure 13(C).

The optical system 11c can change the size Lc of the spot shape in response to the requirements of the irradiation target area. The optical system 11c can know the requirements of the irradiation target area by some means (for example, a light request signal from the irradiation target area, an instruction signal from an operator, etc.).
Furthermore, the optical system 11c may periodically change the positional relationship as shown in FIGS. 13(A) to 13(B), (B) to 13(C), and (C) to 13(A).

Figures 13 (D1) to 13 (D3) are diagrams explaining how the optical system 11c adjusts the coupling state (adjusts the positional relationship) while shifting the optical axis of the light L1 from the central axis of the bundle optical fiber 36.

The optical system 11c narrows the size Lc of the spot shape of the light L1 to the extent that only one single-core optical fiber 51a or a plurality of single-core optical fibers 51a are included. Then, the optical system 11c adjusts the positional relationship between the optical axis of the light L1 and the central axis of the bundle optical fiber 36 so that the single-core optical fiber 51a corresponding to the irradiation target area requesting light is included within the size Lc of the spot shape. If the irradiation target area requesting light changes, the optical system 11c changes the positional relationship accordingly, such as from FIG. 13 (D1) to FIG. 13 (D2) or from FIG. 13 (D1) to FIG. 13 (D3). The optical system 11c can know that the irradiation target area requesting light has changed by some means (for example, a light request signal from the irradiation target area or an instruction signal from the operator).
Furthermore, the optical system 11c may rotate the spot of the light L1 clockwise as shown in FIG. 13 from (D1) to (D2), (D2) to (D3), and (D3) to (D1).

The optical system 11c having the above-mentioned functions may be mechanically controlled or optically controlled.
For example, in the case where the optical system 11c is mechanically controlled, when adjusting the size Lc of the spot shape as shown in Figures 13(A) to 13(C), the optical system 11c adjusts the distance between the light source unit 11 and one end T1 of the bundle optical fiber 36. Also, when adjusting the light coupling position as shown in Figures 13(D1) to 13(D3), the optical system 11c adjusts the positional relationship between the optical axis of the light L1 and the central axis of the bundle optical fiber 36.

On the other hand, if the optical system 11c is an optical control system, when adjusting the size Lc of the spot shape as shown in Figures 13 (A) to (C), the focal position of the lens provided is adjusted. Also, when adjusting the light coupling position as shown in Figures 13 (D1) to (D3), the optical system 11c adjusts the optical components provided (condenser lens, wide-angle lens, beam splitter, prism, mirror, etc.).

(Embodiment 5)
FIG. 14 is a flowchart illustrating an optical transmission method performed by the optical transmission system described in the first to third embodiments.
Propagating light L1 from the light source unit 11 using a bundle optical fiber 36 formed by bundling a plurality of single optical fibers as the optical transmission path 26 (step S01);
In the optical branching unit 12b, the light L1 propagated through the optical transmission line 26 is branched into a plurality of output ports at an arbitrary branching ratio (step S02);
Propagating light L2 from each of the output ports of the optical branching unit 12b to each of the irradiation target areas (step S03); and Adjusting the branching ratio for the optical branching unit 12b so that the power of the light L2 irradiated to the irradiation target area becomes a target (step S04).
I do.

The "goal" in step S04 is to "equalize the power of the light L2 irradiated to the irradiation target area" as described in the first embodiment, or to "set the power of the light L2 irradiated to the irradiation target area to the required value for each irradiation target area" as described in the second embodiment.

(supplement)
In this embodiment, the shape (spot) of the light L1 on a plane perpendicular to the optical axis is expressed as a circle. However, the spot of the light L1 is not limited to a circle. There are also cases where the spot of the light L1 emitted by the light source unit 11 has a shape other than a circle (for example, an ellipse or a polygon). Since the present invention includes such cases, the above-mentioned "spot shape" includes a circle and a shape other than a circle.

(Additional Note)
The optical transmission system of the present invention comprises:
an optical transmission path that propagates light from a light source unit using an optical fiber bundle in which a plurality of single optical fibers are bundled;
an optical branching unit that branches the light propagated through the optical transmission line into a plurality of output ports at an arbitrary branching ratio;
a control unit that adjusts the branching ratio of the optical branching unit;
a path for propagating the light from each of the output ports of the optical branching unit to each of the irradiation target areas;
Equipped with.

In the optical transmission system of the present invention,
The optical branching unit is an optical separation unit that separates the single optical fibers bundled in the optical fiber bundle,
The optical splitter has a shutter for each of the output ports, and the controller instructs each of the shutters to open or close as an adjustment of the splitting ratio.

In the optical transmission system of the present invention,
The optical branching unit includes:
a multiplexer, the number of which is equal to the number of the output ports, for outputting the light to each of the corresponding output ports;
an optical switch, the number of which is the same as the number of the single optical fibers bundled in the bundle optical fiber, for outputting the light from the corresponding single optical fiber to one of the multiplexers or to a terminal end;
[0043]

Furthermore, the optical branching unit may have a demultiplexer between the multiplexer and the output port, which couples the light output by the multiplexer to all of the single optical fibers bundled in the bundle optical fiber of the path.

11: Light source unit 11a: Ultraviolet light source unit 11c: Optical system 12: Light branching unit (equal branching)
12b: Optical branching unit (active)
12d: Optical separation unit (active)
13, 13-1, ..., 13-n, ..., 13-N: Irradiation unit 14: Path (each single-core optical fiber 51a bundled in the bundle optical fiber 36)
15: Control unit 15b: Control unit 16: Optical transmission path 26: Optical transmission path 36: Bundle optical fiber 37: Bundle optical fiber 51a of a path: Single-core optical fiber 55: Single-core optical fiber 121 of a path: Core separation adapter 123: Optical fiber 125: Optical fiber 131: Optical switch 132: Output port 133: Multiplexer 135: Terminator 139: Core separation adapter 141: Shutter 301: Optical transmission system L1, L2: Light Lc: Size of optical spot AR1, AR2, ..., ARn, ..., ARN: Irradiation target area

Claims

an optical transmission path that propagates light from a light source unit using an optical fiber bundle in which a plurality of single optical fibers are bundled;
an optical branching unit that branches the light propagated through the optical transmission line into a plurality of output ports at an arbitrary branching ratio;
a control unit that adjusts the branching ratio of the optical branching unit;
a path for propagating the light from each of the output ports of the optical branching unit to each of the irradiation target areas;
An optical transmission system comprising:
The optical transmission system according to claim 1, characterized in that all of the paths are single optical fibers.
The optical transmission system according to claim 1, characterized in that all of the paths are bundled optical fibers consisting of multiple single optical fibers.
The goal is to make the power of the light irradiated onto the irradiation target area uniform;
2. The optical transmission system according to claim 1, wherein the control unit adjusts the branching ratio so as to approach the target.
The power of the light irradiated to the irradiation target area is set to a required value for each of the irradiation target areas;
2. The optical transmission system according to claim 1, wherein the control unit adjusts the branching ratio so as to approach the target.
An optical branching unit that branches light from an optical bundle formed by bundling a plurality of single optical fibers into a plurality of output ports at an arbitrary branching ratio,
a multiplexer, the number of which is equal to the number of the output ports, for outputting the light to each of the corresponding output ports;
an optical switch, the number of which is the same as the number of the single optical fibers bundled in the bundle optical fiber, for outputting the light from the corresponding single optical fiber to one of the multiplexers or to a terminal end;
a core separation adapter for separating the bundled optical fibers and connecting each of the single optical fibers to the optical switch;
An optical branching unit comprising:
a demultiplexer between the multiplexer and the output port, the demultiplexer coupling the light output from the multiplexer to all single optical fibers bundled in a bundle optical fiber connected to the output port;
7. The optical branching section according to claim 6, wherein each of the multiplexers and the demultiplexers is connected to each other by a single optical fiber.
Propagating light from a light source unit using an optical bundle formed by bundling a plurality of single optical fibers as an optical transmission path;
In an optical branching unit, the light propagated through the optical transmission line is branched into a plurality of output ports at an arbitrary branching ratio;
An optical transmission method comprising: propagating the light from each of the output ports of the optical branching unit to each of the irradiation target areas; and adjusting the branching ratio of the optical branching unit so that the power of the light irradiated to the irradiation target area becomes a target.