WO2023058144A1

WO2023058144A1 - Ultraviolet light irradiation system and ultraviolet light irradiation method

Info

Publication number: WO2023058144A1
Application number: PCT/JP2021/036936
Authority: WO
Inventors: 誉人桐原; 亜弥子岩城; 聖成川; 友宏谷口; 和秀中島; 隆松井; 信智半澤; 悠途寒河江; 千里深井
Original assignee: 日本電信電話株式会社
Priority date: 2021-10-06
Filing date: 2021-10-06
Publication date: 2023-04-13

Abstract

The purpose of the present invention is to provide an ultraviolet light irradiation system that can ensure the safety and operability for handling ultraviolet light and a method thereof.　An ultraviolet light irradiation system 301 according to the present invention comprises: a light source part 11 that outputs ultraviolet light and visible light; an optical fiber transmitting part 14 that propagates the ultraviolet light and the visible light; and an irradiating part 13 that irradiates an identical irradiation target region AR with the ultraviolet light and the visible light that have been propagated by the optical fiber transmitting part 14. The light source part 11 simultaneously outputs, to an optical fiber coupling part 16, the ultraviolet light (approximately 100 to 400 nm band) and the visible light visually recognizable by the human (approximately 400 to 800 nm band). The optical fiber coupling part 16 inputs, to the optical fiber transmitting part 14, the ultraviolet light and the visible light that the light source part 11 has outputted. The optical fiber transmitting part 14 transmits, to the irradiating part 13, the ultraviolet light and the visible light that have been inputted by the optical fiber coupling part 16.

Description

Ultraviolet light irradiation system and ultraviolet light irradiation method

The present disclosure relates to an ultraviolet light irradiation system and method for sterilizing and inactivating viruses using ultraviolet light.

Demand is increasing for systems that perform sterilization and virus inactivation using ultraviolet light for the purpose of preventing infectious diseases. There are three main categories of products in this system. In this specification, the term “sterilization, etc.” shall mean sterilization and virus inactivation.
(I) Mobile sterilization robot The product of Non-Patent Document 1 is an autonomous mobile robot that irradiates ultraviolet light. By irradiating the robot with ultraviolet light while moving in a room in a building such as a hospital room, the robot can automatically realize sterilization in a wide range without human intervention.
(II) Stationary air purifier The product of Non-Patent Document 2 is a device that is installed on the ceiling or at a predetermined place in a room, and performs sterilization while circulating the air in the room. Since this device does not directly irradiate ultraviolet light and has no effect on the human body, highly safe sterilization is possible.
(III) Portable Sterilization Apparatus The product of Non-Patent Document 3 is a portable apparatus equipped with an ultraviolet light source. A user can bring the device to a desired area and irradiate it with ultraviolet light. Therefore, the device can be used in various places.

However, the device described in Non-Patent Document has the following problems.
(1) Economy Since the product of Non-Patent Document 1 is irradiated with high-output ultraviolet light, the apparatus becomes large and expensive. Therefore, the product of Non-Patent Document 1 has a problem that it is difficult to realize an economical system.
(2) Versatility In the product of Non-Patent Document 1, since the ultraviolet light irradiation position is limited to a place where the robot can move/enter, it is difficult to irradiate the ultraviolet light to a small place or a deep place.
Since the product of Non-Patent Document 2 sterilizes the circulated indoor air, it is not possible to directly irradiate a place to be sterilized with ultraviolet light.
The product of Non-Patent Document 3, for example, cannot irradiate ultraviolet light to narrow pipes or areas where people cannot enter.
Thus, the product of Non-Patent Literature has a problem of versatility in that it can irradiate any place with ultraviolet light.
(3) Operability The product of Non-Patent Document 3 is portable and can be irradiated with ultraviolet light at various locations. However, in order to obtain sufficient effects such as sterilization at the target location, the user is required to have skill and knowledge, and there is a problem in operability.

For these problems, an ultraviolet light irradiation system 300 using an optical fiber as shown in FIG. 1 is conceivable. This ultraviolet light irradiation system uses a thin and flexible optical fiber to transmit ultraviolet light from the ultraviolet light source unit 11a, and the ultraviolet light output from the tip of the optical fiber transmission unit 14 is used to pinpoint an irradiation target area to be sterilized. Illuminate the AR. The versatility of the above problem (2) can be solved because the ultraviolet light can be applied to any place simply by moving the irradiation unit 13 at the tip of the optical fiber transmission unit 14 . In addition, since there is no need to move or set the ultraviolet light source, and the user is not required to have skills or knowledge, the operability of the above problem (3) can be resolved. Furthermore, by providing an optical distribution unit 12 such as an optical splitter in the optical fiber transmission unit 14 to form a P-MP (Point to MultiPoint) system configuration such as FTTH (Fiber To The Home), a single light source By sharing, you can sterilize multiple places. Therefore, it is possible to solve the problem (1) economically.

However, there are the following problems in realizing a P-MP configuration using an optical fiber as an ultraviolet light irradiation system.
Deep ultraviolet light used for sterilization or the like has a wavelength band of 200 nm. There are concerns that ultraviolet light in this band may cause cataracts and skin cancer if the eyes and skin of living things, including humans, are exposed to it. Desired. However, the ultraviolet light in that band is invisible to the human eye, and it is difficult for the operator to grasp the ultraviolet light emitted from the irradiation unit 13 and its irradiation range. On the other hand, if a power meter, an ultraviolet light camera, etc. are simultaneously used to monitor the ultraviolet light and its irradiation range in order to ensure safety, the system configuration and work will be complicated, and operation will become difficult.
In other words, it is difficult to ensure safety and operability for handling ultraviolet light in the P-MP configuration ultraviolet light irradiation system using optical fibers.

Therefore, in order to solve the above problems, an object of the present invention is to provide an ultraviolet light irradiation system and method that can ensure safety and operability for handling ultraviolet light.

In order to achieve the above object, the ultraviolet light irradiation system according to the present invention irradiates visible light to the same range at the same time as irradiating ultraviolet light.

Specifically, the ultraviolet light irradiation system according to the present invention includes a light source unit that outputs ultraviolet light and visible light, an optical fiber transmission unit that propagates the ultraviolet light and the visible light, and the optical fiber transmission unit that propagates the ultraviolet light and the visible light. and an irradiation unit that irradiates the same irradiation target area with the ultraviolet light and the visible light.

Further, the ultraviolet light irradiation method according to the present invention includes: outputting ultraviolet light and visible light from a light source unit; propagating the ultraviolet light and the visible light from an optical fiber transmission unit; is irradiated from the irradiation unit to the same irradiation target area.

This ultraviolet light irradiation system and method irradiate an irradiation target area by superimposing visible light on ultraviolet light. Since the visible light is superimposed, the operator can easily grasp the irradiation area of the ultraviolet light without using a power meter or an ultraviolet light camera. Therefore, the present invention can provide an ultraviolet light irradiation system and method that can ensure safety and operability for handling ultraviolet light.

The irradiation unit of the ultraviolet light irradiation system according to the present invention is characterized in that the irradiation area of the visible light is made larger than the irradiation area of the ultraviolet light in the irradiation target area. Safety can be further enhanced.

The ultraviolet light irradiation system according to the present invention is characterized by irradiating the irradiation target area with the visible light before the ultraviolet light. Safety can be further enhanced.

The ultraviolet light irradiation system according to the present invention is characterized by further comprising a controller that expresses the intensity of the ultraviolet light with the visible light. Workers can intuitively recognize the degree of danger.

The optical fiber transmission unit of the ultraviolet light irradiation system according to the present invention is characterized by propagating the ultraviolet light and the visible light through the same core, or propagating the ultraviolet light and the visible light through different cores. .

The above inventions can be combined as much as possible.

The present invention can provide an ultraviolet light irradiation system and method that can ensure safety and operability for handling ultraviolet light.

It is a figure explaining the subject of this invention. It is a figure explaining the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the light source part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the light source part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining operation|movement of the light source part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the light source part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the optical fiber coupling part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the structure of an optical fiber cable. It is a figure explaining the optical fiber coupling part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the optical fiber coupling part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the optical fiber coupling part of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the structure of an optical fiber. It is a flow chart explaining an ultraviolet light irradiation method concerning the present invention.

An embodiment of the present invention will be described with reference to the attached drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In addition, in this specification and the drawings, constituent elements having the same reference numerals are the same as each other.

(Embodiment 1)
FIG. 2 is a diagram illustrating the ultraviolet light irradiation system 301 of this embodiment. The ultraviolet light irradiation system 301 is
a light source unit 11 that outputs ultraviolet light and visible light;
an optical fiber transmission unit 14 that propagates the ultraviolet light and the visible light;
an irradiation unit 13 that irradiates the same irradiation target area AR with the ultraviolet light and the visible light propagated by the optical fiber transmission unit 14;
Prepare.

The optical fiber transmission unit 14 can also transmit ultraviolet light and visible light to a plurality of irradiation target areas AR by arranging the light distribution unit 12 in the middle, like the ultraviolet light irradiation system 302 in FIG. The optical distributor 12 may be composed of, for example, an optical splitter, an optical switch, or a combination thereof.

The basic operation of each component of the ultraviolet light irradiation system (301, 302) is as follows.
The light source unit 11 simultaneously outputs ultraviolet light (approximately 100 to 400 nm band) and visible light (approximately 400 to 800 nm band) visible to humans to the optical fiber coupling unit 16 .
The optical fiber coupling section 16 inputs the ultraviolet light and the visible light output from the light source section 11 to the optical fiber transmission section 14 .
The optical fiber transmission unit 14 transmits the ultraviolet light and visible light input from the optical fiber coupling unit 16 to the irradiation unit 13 .

The irradiation unit 13 simultaneously irradiates the same irradiation target area AR with the ultraviolet light and the visible light transmitted by the optical fiber transmission unit 14 . In order to further ensure safety, the irradiation unit 13 may be set so that the irradiation area of the visible light to the irradiation target area AR is larger than the irradiation area of the ultraviolet light.

[Embodiment 1 of light source part]
FIG. 4 is a diagram for explaining the configuration (example 1) of the light source unit 11. As shown in FIG.
The light source unit 11 includes an ultraviolet light source unit 11a, a visible light source unit 11b, and a control unit 11c.
The ultraviolet light source unit 11a generates ultraviolet light UV (wavelength band of 100 nm to 400 nm) effective for sterilization and the like based on instructions from the control unit 11c.
The visible light source section 11b generates visible light VL (wavelength band of 400 nm to 800 nm) visible to humans based on instructions from the control section 11c.

The control unit 11c has a control function for simultaneously generating ultraviolet light and visible light for the ultraviolet light source unit 11a and the visible light source unit 11b, and transmits a control signal CS1 to each light source unit. Further, the control unit 11c may irradiate the visible light before starting the irradiation of the ultraviolet light, instead of irradiating the ultraviolet light and the visible light at the same time, in order to further ensure the safety.

Alternatively, the irradiation unit 13 or the sensor 11d arranged in the irradiation target area AR may detect whether or not the ultraviolet light and the visible light are simultaneously irradiated in the same range. The control unit 11c may receive the irradiation status information CS2 detected by the sensor 11d in advance or in real time, and may perform feedback control on the ultraviolet light source unit 11a and the visible light source unit 11b. By grasping the irradiation status information of the irradiation unit 13 and the irradiation target area AR, the control unit 11c can, for example, immediately stop irradiation when there is a person near the irradiation target area AR to improve safety. .
This feedback control is intended to avoid a situation where only the visible light is not irradiated to the irradiation target area AR due to some problem in the optical fiber coupling section 16, the optical fiber transmission section 14, or the irradiation section 13 after the light source section 11. aim. Specifically, the sensor 11d informs the control unit 11c of the irradiation conditions (for example, the illuminance of the visible light in the irradiation target area AR and the phase of the visible light in the irradiation unit 13) as information. The control unit 11c controls the ultraviolet light source unit 11a based on the information to turn on/off the ultraviolet light. This feedback control avoids situations in which only ultraviolet light is irradiated, and can improve the safety of the ultraviolet light irradiation system.

[Embodiment 2 of light source part]
FIG. 5 is a diagram for explaining the configuration (example 2) of the light source unit 11. As shown in FIG. The light source unit 11 in FIG. 5 includes an ultraviolet light source unit 11a, a visible light source unit 11b, and a control unit 11c, which is the same as the light source unit 11 in FIG.

The light source unit 11 in FIG. 5 is different from the light source unit 11 in FIG. 4 in that the control unit 11c expresses the intensity of the ultraviolet light with visible light. Specifically, the control unit 11c displays the power of the ultraviolet light as (1) the power of the visible light (brightness/darkness).
(2) display with a flashing pattern of visible light; or (3) display with a hue of visible light.
By expressing with visible light in this way, a person in the vicinity of the irradiation target area AR can intuitively recognize the degree of danger.
The power of the ultraviolet light means the power of the ultraviolet light output by the ultraviolet light source unit 11a, the power of the ultraviolet light emitted by the irradiation unit 13 detected by the sensor 11d in FIG. 7, or the sensor 11d in FIG. Any of the powers of the ultraviolet light received by the irradiation target area AR detected in step 1 may be used.

FIG. 6 is a table for explaining changes in visual recognition pattern of visible light based on the power of ultraviolet light.
When the power of the ultraviolet light is represented by the power of the visible light, for example, if the power of the ultraviolet light is strong, the power of the visible light is also increased (brighter) so that a person in the vicinity of the irradiation target area AR recognizes that the danger is high. Conversely, if the power of the ultraviolet light is weak, the power of the visible light is also weak (dark), thereby making it possible to increase the sense of security for people in the vicinity of the irradiation target area AR.
In addition, when expressing the ultraviolet light power by the blinking pattern of visible light, for example, if the ultraviolet light power is strong, the visible light blinks at a high frequency (e.g., 5 times/second) to indicate that the irradiation target has a high degree of danger. The area AR is made to be recognized by people in the vicinity. Conversely, if the power of the ultraviolet light is weak, blinking the visible light at a low frequency (for example, once per second) can increase the sense of security for people in the vicinity of the irradiation target area AR.
Further, when the ultraviolet light power is represented by the hue of visible light, for example, if the ultraviolet light power is strong, the person in the vicinity of the irradiation target area AR is made to recognize that the danger is high as violet visible light. Conversely, if the power of the ultraviolet light is weak, the blue visible light can increase the sense of security for people in the vicinity of the irradiation target area AR.

As another method, a visible light emitting element (eg, LED) 11e may be installed near the irradiation unit 13, and the control unit 11c may cause the LED to emit light in the above-described visible pattern according to the power of the ultraviolet light.

By performing such control by the control unit 11c, it is possible not only to display irradiation/non-irradiation of ultraviolet light by simple ON/OFF of visible light, but also to visualize the degree of danger depending on the power of ultraviolet light. can be done. Furthermore, the control unit 11c performs this control, so that the state of the ultraviolet light can be visually recognized even when there is another light-emitting body such as a lighting device in the irradiation target area AR.

[Embodiment 3 of light source part]
FIG. 7 is a diagram for explaining the configuration (example 3) of the light source unit 11. As shown in FIG.
The light source unit 11 includes a visible light source unit 11b, a wavelength conversion function unit 11f, and a control unit 11c.
The visible light source section 11b generates visible light VL (wavelength band of 400 nm to 800 nm) visible to humans based on instructions from the control section 11c.

The wavelength conversion function unit 11f uses part of the visible light from the visible light source unit 11b to convert it into ultraviolet light (wavelength band of about 100 to 400 nm) that is effective for sterilization, etc., and instructs the control unit 11c. to generate ultraviolet light. The control unit 11c in FIG. 7 does not irradiate ultraviolet light and visible light at the same time as described in FIG. You can

The control unit 11c has a control function for simultaneously generating ultraviolet light and visible light for the visible light source 11b and the wavelength conversion function unit 11f, and transmits a control signal CS1 to each. In addition, as described in FIG. 4, the control unit 11c in FIG. Feedback control may be performed on the light source 11b and the wavelength conversion function unit 11f.

Further, in the embodiment of FIG. 7, the configuration in which the wavelength of visible light is converted to generate ultraviolet light has been described, but the wavelength of ultraviolet light may be converted to generate visible light.
Furthermore, also in the embodiment of FIG. 7, as described in the second embodiment, the visual recognition pattern of visible light may be changed according to the power of ultraviolet light.

[Example 1 of the optical fiber coupling part]
FIG. 8 is a diagram for explaining the configuration (example 1) of the optical fiber coupling section 16. As shown in FIG. The optical fiber coupling section 16 optically couples the ultraviolet light and visible light transmitted from the light source section 11 to the optical fiber transmission section 14 . The optical fiber coupling section 16 differs depending on the type of the optical fiber transmission section 14 (that is, optical fiber), but (α) wavelength-multiplexes and couples two wavelengths of ultraviolet light and visible light to a single core (or core section). and (β) a configuration in which ultraviolet light and visible light are coupled to different cores, respectively.

The optical fibers having different cores are an optical cable (a bundle of a plurality of single-core optical fibers 21) as shown in FIG. 9A and a multi-core optical fiber 23 (a plurality of cores) as shown in FIG. an optical fiber having a core 22), or a multi-core optical cable (a bundle of a plurality of multi-core optical fibers 23) as shown in FIG. 9C.

The optical fiber coupling section 16 includes a first correction section 16a, a condensing section 16b, and a second correction section 16c.
The first correction unit 16a receives the ultraviolet light UV and the visible light VL transmitted from the light source unit 11, corrects deviation and inclination of the optical axis, and inputs the light to the light collecting unit 16b. The first correction unit 16a is composed of an optical system lens.
The light condensing part 16b receives the ultraviolet light UV and the visible light VL from the first correcting part 16a, converges the light to about the diameter of the core of the optical fiber that is the optical fiber transmission part 14, or the core part, and the second correcting part Enter 16c. The condensing part 16b is composed of an optical system lens.
The second correction unit 16c receives the ultraviolet light UV and the visible light VL condensed by the condensing unit 16b, corrects the misalignment and inclination of the optical axis, and enters the optical fiber transmission unit . The second corrector 16c is composed of an optical system lens.

The optical fiber coupling section 16 of the present embodiment has a simple configuration, for example, it can be realized by combining optical system lenses, so there is an advantage that it can be realized at a low cost.

[Embodiment 2 of Optical Fiber Coupling Portion]
FIG. 10 is a diagram illustrating a configuration (example 2) of the optical fiber coupling section 16. As shown in FIG.
The optical fiber coupling section 16 of FIG. 10 further includes a monitoring section 16d and a control section 16e in contrast to the optical fiber coupling section 16 of FIG.
The monitoring unit 16d monitors the transmission status of the ultraviolet light and visible light transmitted from the second correction unit 16c and incident on the optical fiber transmission unit 14. FIG. The monitoring unit 16d transmits the transmission status information CS3 to the control unit 16e. Here, the transmission status is, for example, the power of the ultraviolet light and the visible light, or the amount of axis deviation between the ultraviolet light and the visible light incident on the optical fiber transmission unit 14 . The purpose of monitoring the transmission status is to avoid the above-described situation in which only visible light is not applied to the irradiation target area AR.
The control unit 16e analyzes the transmission status information CS3 received from the monitoring unit 16d, and sends a control signal CS4 to the first correction unit 16a, the light collection unit 16b, and the second correction unit 16c so as to optimize the transmission status, control each. Specifically, the first correction unit 16a and the second correction unit 16c are optical fiber couplers (positioners), and the control unit 16e uses these to correct axial deviation of visible light and ultraviolet light based on the transmission situation. can do. Further, when only the power of the ultraviolet light is present and the power of the visible light is absent, the control unit 16e shifts the optical axis of the ultraviolet light using the first correction unit 16a and the second correction unit 16c so that the ultraviolet light is incident on the optical fiber transmission unit 14. You can also choose not to.
Also, the first corrector 16a and the second corrector 16c may be optical amplifiers or optical attenuators. When only the power of the ultraviolet light is present and the power of the visible light is absent, the control unit 16e can attenuate the ultraviolet light in the first correcting unit 16a and the second correcting unit 16c, and prevent the ultraviolet light from entering the optical fiber transmission unit 14. .

Since the optical fiber coupling unit 16 of the present embodiment has the control unit 16e, the irradiation timing of the light can be controlled by, for example, irradiating the ultraviolet light and the visible light at the same time or irradiating the visible light first to ensure safety. can be adjusted.

[Embodiment 3 of Optical Fiber Coupling Portion]
FIG. 11 is a diagram illustrating a configuration (example 3) of the optical fiber coupling section 16. As shown in FIG.
11 is different from the optical fiber coupling portion 16 in FIG. 8 in that the first correction portions are for ultraviolet light (first correction portion 16a#1) and for visible light (first correction portion 16a#2). ), and further includes a multiplexing unit 16f.
The multiplexing unit 16f multiplexes the wavelengths of the ultraviolet light and the visible light from the first correcting units 16a#1 and #2, and transmits the multiplexed light to the light collecting unit 16b. The multiplexing section 16f is composed of an optical wavelength multiplexing coupler, an optical lens, or a prism.

In the optical fiber coupling section 16 of the present embodiment, the first correction section is divided for ultraviolet light and visible light, so that the transmission power of ultraviolet light and visible light is optimized according to the wavelength characteristics of the optical fiber transmission section 14. can be
In addition, it is difficult to suddenly combine two lights, ultraviolet light and visible light, and wavelength-multiplex them into various types of optical fibers having smaller cores or core portions, especially single-core optical fibers. For this reason, as a first step, the combining unit 16f combines the ultraviolet light and the visible light, as a second step, the wavelength-multiplexed light is collected to the core level of the optical fiber in the collecting unit 16b, and as a third step, Optical axis adjustment is performed by the second correction unit 16c. By performing wavelength multiplexing step by step in this manner, coupling efficiency and transmission efficiency can be improved.

[Embodiment 4 of Optical Fiber Coupling Portion]
FIG. 12 is a diagram illustrating a configuration (example 4) of the optical fiber coupling section 16. As shown in FIG.
The optical fiber coupling section 16 of FIG. 12 further includes a monitoring section 16d and a control section 16e in contrast to the optical fiber coupling section 16 of FIG.
The monitoring unit 16d monitors the transmission status of the ultraviolet light and visible light transmitted from the second correction unit 16c and incident on the optical fiber transmission unit 14. FIG. The monitoring unit 16d transmits the transmission status information CS3 to the control unit 16e. The transmission status is as described above.
The control unit 16e analyzes the transmission status information CS3 received from the monitoring unit 16d, and adjusts the first correction units (16a #1 and #2), the light collection unit 16b, and the second correction unit 16c so that the transmission status becomes optimal. to control each of them. The specific contents of control are as described above.

When wavelength-multiplexed light is transmitted over long distances through optical fibers, the irradiation power of specific wavelengths may decrease due to chromatic dispersion. Since the optical fiber coupling section 16 of the present embodiment includes the first correction section for each wavelength, the influence of chromatic dispersion in the optical fiber transmission line 14 can be reduced (attenuation of the irradiation power can be suppressed). For example, the first corrector (16a #1, #2) is a spatial optical system using a fiber Bragg grating (FBG), a circulator, or the like. This spatial optical system performs dispersion compensation for a desired wavelength band according to the length of the optical fiber transmission section 14 .

In optical fiber transmission in the optical communication band (T-band to U-band of about 1000 nm to 1675 nm), for example, dispersion-shifted fiber and dispersion-compensating fiber are used, and it is possible to change the refractive index profile of the optical fiber. realized by In the ultraviolet light irradiation system of this embodiment as well, especially when the distance of the optical fiber transmission section 14 is long, the propagation characteristics of each light are different. can reduce the influence of chromatic dispersion.

[Embodiment of optical fiber transmission unit]
The optical fiber transmission section 14 propagates the ultraviolet light and the visible light that are incident at the optical fiber coupling section 16 to the irradiation section 13 . The optical fiber transmission section 14 is an optical fiber. Since it is an optical fiber, it can be installed in narrow places where conventional robots and devices cannot enter.

As described above, the optical fiber transmission unit 14 includes:
(α) a configuration in which two wavelengths of ultraviolet light and visible light are wavelength-multiplexed and coupled to a single core (or core portion);
(β) Configuration in which ultraviolet light and visible light are coupled to different cores (see FIG. 9)
There is

An optical fiber having a cross section as shown in FIG. 13 can be used for the optical fiber of the optical fiber transmission section 14 . In addition to the solid optical fiber using a general additive as shown in FIG. 13 (1), the optical fiber having the hole structure described in FIGS. It may be a multi-core optical fiber having a plurality of core regions described in 6) or an optical fiber having a structure combining them (FIGS. 13(7) to 13(10)).

A variation of the above single-core optical fiber (α) will be described. It is an optical fiber having a structure of (1) to (5) in FIG.
(1) Solid Core Optical Fiber This optical fiber has one solid core 52 in the clad 60 having a higher refractive index than the clad 60 . "Full" means "not hollow". The solid core can also be realized by forming an annular low refractive index region in the clad.
(2) Hole-assisted optical fiber This optical fiber has a solid core 52 in the clad 60 and a plurality of holes 53 arranged around the core. The medium of the holes 53 is air, and the refractive index of air is sufficiently smaller than that of quartz-based glass. Therefore, the hole-assisted optical fiber has a function of returning light leaking from the core 52 due to bending or the like back to the core 52, and is characterized by a small bending loss.
(3) Hole structure optical fiber This optical fiber has a hole group 53a of a plurality of holes 53 in the clad 60, and has an effective refractive index lower than that of the host material (glass or the like). This structure is called a photonic crystal fiber. This structure can take a structure in which a high-refractive-index core with a changed refractive index does not exist, and light can be confined using the region 52a surrounded by the holes 53 as an effective core region. Compared to optical fibers with solid cores, photonic crystal fibers can reduce the effects of absorption and scattering losses due to additives in the core. Optical characteristics that cannot be realized can be realized.
(4) Hollow core optical fiber This optical fiber has a core region made of air. Light can be confined in the core region by forming a photonic bandgap structure with a plurality of holes in the cladding region or an anti-resonant structure with glass wires. This optical fiber has low nonlinear effects and is capable of delivering high power or high energy lasers.
(5) Coupling Core Optical Fiber In this optical fiber, a plurality of solid cores 52 having a high refractive index are closely arranged in a clad 60 . This optical fiber guides light by optical wave coupling between solid cores 52 . Coupling-core type optical fibers can disperse and send light as many times as the number of cores, so high power can be used for efficient sterilization.Coupling-core type optical fibers mitigate fiber deterioration due to ultraviolet rays and have a long life. It has the advantage of being able to

A variation of the multi-core optical fiber among the above (β) will be explained. It is an optical fiber having a structure of (6) to (10) in FIG.
(6) Solid-core type multi-core optical fiber In this optical fiber, a plurality of solid cores 52 with a high refractive index are spaced apart in a clad 60 . This optical fiber guides light in such a manner that the optical wave coupling between the solid cores 52 is sufficiently small so that the effect of the optical wave coupling can be ignored. Therefore, the solid-core multi-core optical fiber has the advantage that each core can be treated as an independent waveguide.
(7) Hole-Assisted Multi-Core Optical Fiber This optical fiber has a structure in which a plurality of hole structures and core regions of (2) above are arranged in a clad 60 .
(8) Hole structure type multi-core optical fiber This optical fiber has a structure in which a plurality of the hole structures of (3) above are arranged in the clad 60 .
(9) Hollow-core multi-core optical fiber This optical fiber has a structure in which a plurality of the hole structures of (4) above are arranged in the clad 60 .
(10) Coupling-core type multi-core optical fiber This optical fiber has a structure in which a plurality of coupling-core structures of (5) above are arranged in a clad 60 .

The above (β) may be an optical fiber cable including a plurality of optical fibers having the structure described above (see FIG. 9).

(Embodiment 2)
FIG. 14 is a diagram for explaining the ultraviolet light irradiation method performed by the ultraviolet light irradiation system (301, 302). This ultraviolet light irradiation method is
outputting ultraviolet light and visible light from the light source unit 11 (step S01);
propagating the ultraviolet light and the visible light in the optical fiber transmission unit 14 (step S02);
irradiating the same irradiation target area AR with the ultraviolet light and the visible light from the irradiation unit 13 (step S03);
characterized by

11a: Ultraviolet light source section 11b: Visible light source section 12: Light distribution section (equally branched)
13, 13-1, ..., 13-N: irradiation section 14: optical fiber transmission section 16: optical fiber coupling section 52: solid core 52a: region 53: hole 53a: hole group 53c: hole 60:

Claddings

300, 301, 302: UV light irradiation system AR1, AR2, ..., ARN: irradiation target area (area to be irradiated with ultraviolet light)

Claims

a light source unit that outputs ultraviolet light and visible light;
an optical fiber transmission unit that propagates the ultraviolet light and the visible light;
an irradiation unit that irradiates the same irradiation target area with the ultraviolet light and the visible light propagated by the optical fiber transmission unit;
An ultraviolet light irradiation system.
The ultraviolet light irradiation system according to claim 1, wherein the irradiation unit makes the irradiation area of the visible light larger than the irradiation area of the ultraviolet light in the irradiation target area.
The ultraviolet light irradiation system according to claim 1, wherein the irradiation target area is irradiated with the visible light before the ultraviolet light.
The ultraviolet light irradiation system according to claim 1, further comprising a controller that expresses the intensity of the ultraviolet light with the visible light.
The ultraviolet light irradiation system according to claim 1, wherein the optical fiber transmission section propagates the ultraviolet light and the visible light through the same core.
The ultraviolet light irradiation system according to claim 1, wherein the optical fiber transmission section propagates the ultraviolet light and the visible light through different cores.
An ultraviolet light irradiation method,
outputting ultraviolet light and visible light from the light source;
Propagating the ultraviolet light and the visible light through an optical fiber transmission unit, and irradiating the same irradiation target area with the ultraviolet light and the visible light from an irradiation unit;
An ultraviolet light irradiation method characterized by: