JP2006133337A - Hollow waveguide for laser energy transmission, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow waveguide for laser energy transmission of an easy-to-see structure by having large strength to external force such as impact, bending and tension, including durability, simply performing wiring and lessening visible light transmission loss used in guide light. <P>SOLUTION: The hollow waveguide for the laser energy transmission comprises a pipe-like member 2 for forming a metal thin film 5 in an inner face, and a dielectric film 3 made of a material having flexibility mainly comprising a styrene resin and adhered on the metal thin film 5. Strength to impact or the like of the dielectric film 3 is large, and even when being bent, exfoliation or breakage does not occur. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hollow waveguide for laser energy transmission used for transmitting laser light and a method for manufacturing the same.

  Laser energy transmission hollow waveguides are used to transmit high-power laser light in various fields of medicine, measurement, and analysis. Patent Document 1 allows transmission with low loss to laser light such as a CO2 laser (carbon dioxide laser) with a wavelength of 10.6 μm, an Er-YAG laser with a wavelength of 2.94 μm, and a CO laser with a wavelength of 5 μm. A hollow waveguide is described.

The conventional hollow waveguide for laser energy transmission described in Patent Document 1 is made by injecting and attaching a cyclic polyolefin solution into a metal pipe, followed by drying and solidifying by performing high-temperature heat treatment. A dielectric film is deposited on the inner surface of a metal pipe, and a hollow region defined by the dielectric film is used as a waveguide.
Japanese Patent Laid-Open No. 2002-71973

  In conventional hollow waveguides for laser energy transmission, the tensile fracture elongation of the cyclic polyolefin constituting the dielectric film is small, so that the dielectric film easily peels off or breaks when subjected to impact, bending, or tension. . For this reason, not only is it inferior in durability, but it is difficult to bend and route the waveguide, and the degree of freedom of routing is small.

  Further, the cyclic polyolefin has a low visible light transmittance, and when the hollow waveguide is bent and used, the visible light transmittance is extremely lowered. For this reason, when visible light is used coaxially as the guide light of the laser light, the transmission loss of the guide light increases, and there is a problem that it is difficult to see. If the transmission loss of the guide light is so large that it is difficult to see, for example, the focal position during the operation becomes difficult to understand and there is a risk of inducing an accident such as an erroneous incision. In order to avoid such a risk, it is necessary to guide the guide light using another fiber without using the guide light coaxially. In this case, the structure becomes complicated. Further, when the hollow waveguide used for laser energy transmission is broken, only the guide light from another fiber is emitted, so that it cannot be determined that the laser output is not output from the hollow waveguide.

  Furthermore, in order to form a dielectric film of cyclic polyolefin, it is necessary to perform baking by heat treatment, which requires not only control over temperature conditions and heating medium, but also the production process is troublesome. There is a problem that takes a long time.

  The present invention has been made in consideration of such problems, has high durability against external forces such as impact, bending, and tension, has durability, and can be routed easily. In addition, it is an object of the present invention to provide a hollow waveguide for laser energy transmission capable of easily forming a dielectric film as well as a visible light transmission loss used for guide light, and a manufacturing method thereof. .

  The hollow waveguide for laser energy transmission according to claim 1 is made of a tubular member whose inner surface is a mirror surface and a flexible material mainly composed of styrene resin. And a dielectric film attached thereto.

  According to the first aspect of the present invention, the dielectric film constituting the waveguide on the inner surface side of the tubular member has flexibility, can follow the bending well, and is sufficient for the tension. Can stretch. In addition, the dielectric film has a high strength against impact by using styrene resin as a main component. As a result, the dielectric film does not peel or break, and has high durability. Therefore, for example, even if a tubular member is bent, it can follow the bending satisfactorily, so that the routing can be performed easily and the degree of freedom of the routing can be increased.

  In addition, the dielectric film is mainly composed of a styrene resin, so that the visible light transmittance is large, and the visible light transmission loss does not increase even when the hollow waveguide is bent. For this reason, even if visible light is passed as the guide light in addition to the laser light, the transmission loss of the guide light is small, and it is easy to see in use and the operability is improved. For this reason, the occurrence of accidents such as erroneous incisions can be prevented. Furthermore, since the guide light can be used coaxially, when the guide light is not output, it is possible to predict that the hollow waveguide used for laser energy transmission is damaged. Judgment can be made.

  Furthermore, the dielectric film can be uniformly dissolved in a solvent by using a styrene resin as a main component, and can be easily deposited from the solvent. Therefore, when depositing on the inner surface of the tubular member, it is only necessary to scatter the solvent, and there is no need to perform heat treatment. As a result, the dielectric film can be easily formed on the inner surface of the tubular member.

  The invention according to claim 2 is the hollow waveguide for laser energy transmission according to claim 1, wherein the dielectric film is a copolymer of styrene resin and butadiene resin.

  The butadiene resin used in the invention of claim 2 has flexibility. For this reason, by forming a dielectric film from a copolymer of a styrene resin and a butadiene resin, the operation according to claim 1 can be performed reliably and easily.

  A third aspect of the present invention is the laser energy transmission hollow waveguide according to the first aspect, wherein the inner surface of the tubular member is coated with a metal thin film.

  As described in claim 3, by coating the inner surface of the tubular member with a metal thin film, the inner surface of the tubular member can be made into a mirror surface, so that the transmission efficiency of laser light can be improved.

  A fourth aspect of the present invention is the hollow waveguide for laser energy transmission according to the third aspect, wherein the metal thin film is a thin film of silver, gold, molybdenum or nickel.

  In the invention of claim 4, since a thin film of silver, gold, molybdenum or nickel is used as the metal thin film, the metal thin film can be easily formed on the inner surface of the tubular member.

  The invention according to claim 5 is the hollow waveguide according to claim 1 or 3, wherein the tubular member is a hollow glass tube made of quartz, a metal pipe, a non-metal pipe, or a fluororesin pipe. .

  As in the invention described in claim 5, by using a hollow glass tube made of quartz, a metal pipe, a non-metal pipe or a fluororesin pipe as the tubular member, it is possible to stably supply the tubular member as a raw material of the hollow waveguide. It becomes.

  According to a sixth aspect of the present invention, there is provided a method for producing a hollow waveguide for laser energy transmission, comprising: a dielectric solution made of a flexible material mainly composed of a styrene resin; The dielectric film is deposited by flowing inside the film, and then the solvent is scattered to deposit the dielectric film.

  In the invention described in claim 6, after the dielectric film is deposited on the inner surface of the tubular member, the dielectric solvent is scattered to deposit the dielectric film, so that heat treatment for depositing the dielectric film is performed. There is no need, and the dielectric film can be easily formed on the inner surface of the tubular member. For this reason, it is possible to easily perform the manufacturing and to perform the rapid manufacturing.

  According to a seventh aspect of the present invention, there is provided a method for producing a hollow waveguide for laser energy transmission, wherein silver is deposited inside a tubular member while flowing a silver ion solution and a reducing solution on the inner surface of the tubular member to form a silver film into the tubular member And coating a dielectric film on the silver film by flowing a dielectric solution made of a flexible material mainly composed of styrene resin into the tubular member, The dielectric film is deposited by scattering the solvent.

  In the invention according to claim 7, in addition to having the same effect as that of claim 6, the inner surface of the tubular member is made into a mirror surface by depositing a silver film by a silver mirror reaction, so that the mirror surface can be easily and quickly formed. Can be performed.

  According to the hollow waveguide for laser energy transmission of the present invention, since the dielectric film has flexibility, the dielectric film peels off or breaks even when an external force such as impact, tension, or bending acts. Therefore, the durability can be improved and the waveguide can be routed reliably and easily. In addition, since the dielectric film is mainly composed of styrene resin, the visible light transmittance is large, and the transmission loss is small even when the visible light is passed as the guide light.

  According to the method for manufacturing a hollow waveguide for laser energy transmission of the present invention, it is not necessary to perform heat treatment for forming the dielectric film on the inner surface of the tubular member, so that the dielectric film can be easily formed. In addition, the manufacturing can be easily controlled and the manufacturing can be performed quickly.

  1 and 2 show a hollow waveguide for laser energy transmission (hereinafter referred to as a hollow waveguide) 1 according to an embodiment of the present invention, and a tubular member 2 and a dielectric attached to the inner surface of the tubular member 2. The hollow region 4 that includes the film 3 and is partitioned by the inner surface of the dielectric film 3 serves as a laser light waveguide. As the laser light, a CO 2 laser with a wavelength of 10.6 μm, an Er-YAG laser with a wavelength near 3 or a CO laser with a wavelength near 5 μm may be used.

  As the tubular member 2, a hollow glass tube made of a metal pipe, a non-metal pipe, a fluororesin pipe or quartz can be used. Laser light is repeatedly reflected at the boundary between the hollow region 4 and the dielectric film 3 and at the boundary between the dielectric film 3 and the tubular member 2 by being introduced into the hollow region 4 on the inner side of the dielectric film 3. Is propagated by For this reason, the inner surface of the tubular member 2 which is a boundary surface with the dielectric film 3 is formed in a mirror surface.

  In this embodiment, the inner surface of the tubular member 2 is coated with a metal thin film 5 to make the inner surface of the tubular member 2 a mirror surface. As the metal thin film 5, a thin film of metal such as silver, gold, molybdenum, nickel or the like can be used. These metal thin films 5 can be formed by subjecting the inner surface of the tubular member 2 to plating treatment, vapor deposition treatment, and other treatments.

  In addition, when forming a silver film as the metal thin film 5, it becomes possible to coat the inner surface of the tubular member 2 simply by performing a silver mirror reaction. The coating of the silver film uses a hollow glass tube as the tubular member 2, and forms a silver film on the inner surface of the hollow glass tube by performing a silver mirror reaction while flowing a reducing solution and a silver ion solution inside the hollow glass tube. It is. In this case, a hollow glass tube having an inner diameter of about 0.5 to 1.0 mm is used. The silver film formed by such a silver mirror reaction has a merit that the laser light can be efficiently reflected because the gap between the particles is narrow and the particles are small. As this silver film, desired reflection can be performed with a thin film thickness of about 0.1 to 0.2 μm.

  As another means for using the inner surface of the tubular member 2 as a mirror surface, a metal pipe may be used as the tubular member 2, and the inner surface of the metal pipe may be subjected to a polishing process such as electrolytic polishing or electric discharge polishing to form a mirror surface. In this case, it is not necessary to coat the inner surface of the tubular member 2 with the metal thin film 5.

  As the dielectric film 3 described above, a flexible material mainly composed of styrene resin is used. By using a material containing styrene resin as a main component as the dielectric film 3, the transmittance of the dielectric film 3 is increased, and laser light can be transmitted with a small loss.

  The dielectric film 3 is deposited on the inner surface of the tubular member 2 by dissolving the above-described material in a solvent such as an organic solvent and causing the solution to flow inside the tubular member 2 so that the dielectric film 3 is attached to the inner surface of the tubular member 2. Adhere to. Thereafter, an inert gas such as nitrogen gas or compressed air or both inert gas and compressed air is supplied to the inside of the tubular member 2, and the dielectric film 3 is deposited by scattering and drying the solvent. be able to. The dielectric film 3 can be deposited not only by this but also by immersing the tubular member 2 in the above-described solution of the material to adhere the dielectric film 3 to the inner surface thereof and then drying in the same manner. In such an operation, the dielectric film 3 can be reliably deposited only by scattering the solvent. This eliminates the need for heat treatment and baking for the deposition of the dielectric film 3, and allows the deposition of the dielectric film 3 to be performed easily and in a short time, and in addition, the number of steps can be reduced. Is possible.

  In this embodiment, by using a styrene resin as a main component as the dielectric film 3, it is possible to provide good transmission efficiency of laser light as described above, and in addition, impact, bending, etc. of the dielectric film 3 It is possible to have a large strength against the external force. Furthermore, since the dielectric film 3 has flexibility, it can not only follow the bending well but also can sufficiently stretch against tension. Accordingly, the dielectric film 3 is not broken or peeled off from the tubular member 2 and can have sufficient durability. Therefore, even if the tubular member 2 is bent for the arrangement of the hollow waveguide 1, the dielectric film 3 can follow the bending well. Thereby, the hollow waveguide 1 can be wired easily and reliably.

  As a material having a styrene resin as a main component and having flexibility, a copolymer of a styrene resin and a butadiene resin can be used. This copolymer has a characteristic of having flexibility as a butadiene resin in addition to having strength against impact as a styrene resin. The degree of polymerization of the styrene resin and the butadiene resin is set in consideration of characteristics required for the dielectric film 3 such as impact resistance and tensile strength. It can be suitably changed within the range of 50 to 10% by weight, more preferably within the range of 60 to 80% by weight of styrene resin and 40 to 20% by weight of butadiene resin. When the styrene resin is less than 50% by weight, the amount of butadiene resin is relatively large and the impact resistance as the dielectric film 3 cannot be provided. When the styrene resin exceeds 90% by weight, it is acceptable. Since flexibility falls more than necessary, it is not preferable.

  As such a copolymer of styrene resin and butadiene resin, for example, trade name “Asaflex 830” (manufactured by Asahi Kasei Chemicals Corporation) can be used. This “Asaflex 830” is a copolymer of 70% by weight of styrene resin and 30% by weight of butadiene resin. Further, “Asaflex 830” is permitted to be used as a material for packaging containers such as PET bottles, and has high safety.

  The film thickness of the dielectric film 3 is appropriately changed depending on the transmitted laser beam. In the case of a carbon dioxide laser having a wavelength of 10.6 μm, about 1.1 to 1.5 μm, more preferably 1 Good film thickness around 3 μm.

  The laser energy transmission hollow waveguide 1 having the above-described configuration can be formed with a length of 1.5 m or more, for example, when the inner diameter of the tubular member 2 is 0.7 mm.

  In addition to the above-described characteristics, such a hollow waveguide 1 is mainly composed of styrene resin as the dielectric film 3, and thus has a high visible light transmittance. Therefore, when laser light is transmitted, even when visible light is introduced into the hollow waveguide 1 coaxially as guide light, the transmission loss of the guide light is small, visible, and operability is improved. Have.

  In addition, the case where a hollow glass tube is used as the tubular member 2 and the inner surface is coated with a silver film will be described. First, the inside of the hollow glass tube is washed with purified water. This cleaning can be easily performed by flowing purified water into the hollow glass tube by the suction force of the vacuum pump. Next, two kinds of solutions, a reducing solution and a silver ion solution, are caused to flow inside the hollow glass tube to cause a silver mirror reaction in the hollow glass tube to coat the inner surface of the hollow glass tube with a silver film. After the coating of the silver film, purified water is poured into the hollow glass tube and washed in the same manner as described above, and then ethanol is injected into the hollow glass tube to remove the attached water. Compressed air and / or inert gas is introduced into the glass tube to evaporate ethanol and remaining moisture, and the coating process is completed.

  After the coating of the silver film, a dielectric film is deposited using “Asaflex 830”. First, water and dust are removed by flowing nitrogen gas into a hollow glass tube coated with silver film. On the other hand, a solution in which “Asaflex 830” is dissolved in cyclohexane is prepared, and this solution is caused to flow into the hollow glass tube to adhere “Asaflex 830” onto the silver film of the hollow glass tube. Thereafter, an inert gas such as nitrogen gas and / or compressed air is allowed to flow inside the hollow glass tube to scatter cyclohexane as a solvent. Thereby, a dielectric film made of “Asaflex 830” can be deposited on the silver film.

  Here, a copolymer of a styrene resin and a butadiene resin such as “Asaflex 830” has a property of being very easily dissolved in cyclohexane. For this reason, the solution of the styrene-butadiene copolymer can be adjusted in a short time, and the dielectric film can be rapidly formed accordingly. As the solvent for “Asaflex 830”, organic solvents other than cyclohexane such as acetone, toluene, diethyl ether, chloroform, etc. can be used.

  A silver film was coated on the inner surface of a hollow glass tube having an inner diameter of 0.7 mm and a length of 1.5 m by the silver mirror reaction described above. On the other hand, by dissolving “Asaflex 830” in cyclohexane, 9% by weight, 9.5% by weight, 10% by weight, 10.5% by weight, and 11% by weight of “Asaflex 830” solution are obtained. Created. These “Asaflex 830” solutions were fed into the hollow glass tube described above at a speed of 14 cm / min to attach “Asaflex 830” to the inner surface of the hollow glass tube. Thereafter, nitrogen gas was allowed to flow into the hollow glass tube to disperse cyclohexane and dried, and a dielectric film made of “Asaflex 830” was deposited to produce a hollow waveguide for laser energy transmission.

  When the created hollow waveguide is used as a carbon dioxide laser transmission path with a wavelength of 10.6 μm, the refractive index of “Asaflex 830” is 1.572, and the refractive index of air in the transmission path is about 1. The film thickness of the dielectric film is 1.3 μm.

  FIG. 3 shows the transmittance of the dielectric film formed by each concentration of “Asaflex 830” described above. In this embodiment, when the concentration is 10% by weight, the transmittance is 84%, which is the best result.

  FIG. 4 shows the transmittance at each bending angle of 90 °, 135 °, 180 °, 225 °, 270 °, 315 °, and 360 ° when the hollow waveguide produced by this example is bent at a radius of 300 mm. The measurement results are shown. As shown in the figure, the transmittance is about 78% even at a bending angle of 360 ° at a radius of 300 mm, which is a good transmittance. Thus, it can be seen that even if the hollow waveguide of this embodiment is bent, the transmission loss does not increase, and the laser beam can be transmitted satisfactorily.

  Table 1 shows the transmittance of visible light in a hollow waveguide in which “Asaflex 830” as a dielectric film and a cyclic polyolefin as a comparative example are formed. This hollow waveguide is a dielectric film formed by feeding “Asaflex 830” and cyclic polyolefin at a concentration of 10% by weight to the above hollow glass tube coated with a silver film at a rate of 14 cm / min. Is formed. As visible light, green light having a wavelength of about 530 nm was transmitted. As can be seen from Table 1, the transmittance of visible light when bent by 90 ° is more than three times that of cyclic polyolefin, and the transmission loss of visible light is small.

  Table 2 shows the characteristic values of “Asaflex 830” and cyclic polyolefin with respect to bending and tension. As shown by the “flexural modulus”, the cyclic polyolefin does not bend unless a 2450 MPa force is applied, whereas the “Asaflex 830” can be bent with a force of 1100 MPa. Further, as indicated by “tensile elongation at break”, cyclic polyolefin breaks when stretched by 10%, whereas “Asaflex 830” does not break until stretched by 250%. As a result, the dielectric film using “Asaflex 830” has flexibility that can follow the bending well and can greatly extend against the tension.

It is sectional drawing of the hollow waveguide for laser energy transmission in one embodiment of this invention. It is sectional drawing of the direction orthogonal to FIG. It is a characteristic view of the transmittance | permeability with respect to the solution concentration in an Example. It is a characteristic view of the transmittance | permeability with respect to the bending angle in an Example.

Explanation of symbols

1 Hollow waveguide for laser energy transmission 2 Tubular member 3 Dielectric film 4 Hollow region 5 Metal thin film

Claims (7)

  A tubular member whose inner surface is a mirror surface, and a dielectric film made of a flexible material mainly composed of styrene resin and deposited on the inner surface of the tubular member. Hollow waveguide for laser energy transmission.   2. The hollow waveguide for laser energy transmission according to claim 1, wherein the dielectric film is a copolymer of styrene resin and butadiene resin.   The hollow waveguide for laser energy transmission according to claim 1, wherein the inner surface of the tubular member is coated with a metal thin film.   4. The hollow waveguide for laser energy transmission according to claim 3, wherein the metal thin film is a thin film of silver, gold, molybdenum or nickel.   4. The hollow waveguide according to claim 1, wherein the tubular member is a hollow glass tube made of quartz, a metal pipe, a non-metal pipe, or a fluororesin pipe.   A dielectric solution made of a flexible material composed mainly of styrene resin is allowed to flow inside a tubular member whose inner surface is a mirror surface to deposit a dielectric film, and then the solvent is scattered. A method of manufacturing a hollow waveguide for laser energy transmission, comprising depositing a dielectric film.   A step of depositing silver inside the tubular member while circulating the silver ion solution and the reducing solution on the inner surface of the tubular member, and coating the inner surface of the tubular member with a silver film; Laser energy transmission characterized in that a dielectric solution made of a material is flowed into a tubular member, and the dielectric film is deposited on the silver film, and then the dielectric film is deposited by scattering the solvent. Method for manufacturing a hollow waveguide for use.

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