JPH0254923B2 - - Google Patents
Info
- Publication number
- JPH0254923B2 JPH0254923B2 JP60076068A JP7606885A JPH0254923B2 JP H0254923 B2 JPH0254923 B2 JP H0254923B2 JP 60076068 A JP60076068 A JP 60076068A JP 7606885 A JP7606885 A JP 7606885A JP H0254923 B2 JPH0254923 B2 JP H0254923B2
- Authority
- JP
- Japan
- Prior art keywords
- dielectric
- loss
- optical waveguide
- low
- wavelength
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims description 16
- 239000007769 metal material Substances 0.000 claims description 8
- 239000003989 dielectric material Substances 0.000 claims description 5
- 230000005684 electric field Effects 0.000 description 11
- 239000002184 metal Substances 0.000 description 11
- 229910052751 metal Inorganic materials 0.000 description 11
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 10
- 229910002092 carbon dioxide Inorganic materials 0.000 description 5
- 239000001569 carbon dioxide Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- LYQFWZFBNBDLEO-UHFFFAOYSA-M caesium bromide Chemical compound [Br-].[Cs+] LYQFWZFBNBDLEO-UHFFFAOYSA-M 0.000 description 2
- 238000012994 industrial processing Methods 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- SBIBMFFZSBJNJF-UHFFFAOYSA-N selenium;zinc Chemical compound [Se]=[Zn] SBIBMFFZSBJNJF-UHFFFAOYSA-N 0.000 description 2
- 229910005866 GeSe Inorganic materials 0.000 description 1
- 229910005900 GeTe Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/032—Optical fibres with cladding with or without a coating with non solid core or cladding
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、低損失な誘電体を内装させた金属中
空光導波路の一つであり、可撓性を有することに
よつて操作性を高め、特に医療及び工業加工に使
用される炭酸ガスレーザ光の伝送に好適な中空光
導波路に関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention is a metal hollow optical waveguide having a low-loss dielectric inside, and has flexibility to improve operability. In particular, the present invention relates to a hollow optical waveguide suitable for transmitting carbon dioxide laser light used in medical and industrial processing.
炭酸ガスレーザは、発振効率が高く大出力を得
ることができるため、医療用のレーザメスや溶
接、切断等の工業加工用として広く用いられるよ
うになつてきている。
Carbon dioxide lasers have high oscillation efficiency and can produce large outputs, so they are becoming widely used as medical laser scalpels and for industrial processing such as welding and cutting.
しかし、その発振波長が10.6μmという赤外領
域にあるため、従来の石英系光フアイバでは損失
が大きく、炭酸ガスレーザ光用導波路として用い
ることはできない。従つて、現在炭酸ガスレーザ
光を導く手段としては、数枚のミラーを用いた中
空伝送が主であり、操作性において極めて不利で
ある。 However, because its oscillation wavelength is in the infrared region of 10.6 μm, conventional silica-based optical fibers have large losses and cannot be used as waveguides for carbon dioxide laser light. Therefore, currently, the main means for guiding carbon dioxide laser light is hollow transmission using several mirrors, which is extremely disadvantageous in terms of operability.
炭酸ガスレーザ光用導波路として赤外フアイバ
の開発が進められているが、より大電力伝送を目
的として金属中空光導波路が提案されている（E.
Garmire、T.Mcmahon、and M.Bass、IEEE J.
Quantum Electron.QE−16、23（1980））。 Although infrared fibers are being developed as waveguides for carbon dioxide laser light, hollow metal optical waveguides have been proposed for the purpose of transmitting larger amounts of power (E.
Garmire, T. Mcmahon, and M. Bass, IEEE J.
Quantum Electron.QE−16, 23 (1980)).
このものは、第３図に示すように断面が矩形構
造をしており、電界が矩形の長軸方向に偏波した
TEモードを入射されることによつて低損失な光
導波路が実現できる。なお、第３図において、３
１は金属、３２は中空領域である。 This device has a rectangular cross section as shown in Figure 3, and the electric field is polarized in the long axis direction of the rectangle.
By inputting the TE mode, a low-loss optical waveguide can be realized. In addition, in Figure 3, 3
1 is a metal, and 32 is a hollow region.
しかしながら、このような光導波路は断面が矩
形をしているため可撓性の方向が一方向であり、
操作性に制限を受ける。
However, since such an optical waveguide has a rectangular cross section, its flexibility is unidirectional.
Operability is limited.
本発明は上記に基いてなされたもので、低損失
伝送が可能であり、しかも可撓性を付与すること
によつて操作性を高めることができる中空光導波
路の提供を目的とするものである。 The present invention has been made based on the above, and aims to provide a hollow optical waveguide that is capable of low-loss transmission and that can improve operability by imparting flexibility. .
高損失な金属で囲まれた光導波路では、電界が
金属壁面に対し平行な電磁波は低損失であるが、
電界が金属壁面に対し垂直な成分を持つようにな
ると極めて高損失になることから、本発明では中
空光領域と金属壁面との間に適当な厚さの誘電体
層を内装させ、これによつて電界が金属壁面に対
し垂直な成分もつ電磁波に対して低損失になるよ
うにしている。
In an optical waveguide surrounded by high-loss metal, electromagnetic waves whose electric field is parallel to the metal wall have low loss.
If the electric field has a component perpendicular to the metal wall surface, the loss will be extremely high. Therefore, in the present invention, a dielectric layer of an appropriate thickness is installed between the hollow optical region and the metal wall surface. This ensures that the electric field has low loss for electromagnetic waves with components perpendicular to the metal wall surface.
また、導波路の断面を楕円にすることによつて
偏波面が保存された安定なモードのみを励振し、
しかも可撓性を付与している。 In addition, by making the cross section of the waveguide elliptical, only stable modes with a preserved polarization plane can be excited.
Moreover, it provides flexibility.
従つて、本発明の特徴点は、複素屈折率が大き
な金属材料よりなる楕円断面を有する中空光導波
路において、長軸方向付近の内側のみに低損失な
誘電体層を膜層が誘電体中の電磁波の波長の１／
４の奇数倍にほぼ比例するように設定して内装し
たことにある（第１発明）。 Therefore, the feature of the present invention is that in a hollow optical waveguide having an elliptical cross section made of a metal material with a large complex refractive index, a low-loss dielectric layer is provided only on the inside near the long axis direction, and the film layer is in the dielectric. 1/ of the wavelength of electromagnetic waves
This is because the interior is set to be approximately proportional to an odd multiple of 4 (first invention).
また、複素屈折率が大きな金属材料よりなる楕
円断面を有する中空光導波路において、周方向に
一様に２種類の異なる屈折率をもつ低損失な誘電
体交互多層膜を膜厚がそれぞれ誘電体中の電磁波
の波長の１／４の奇数倍にほぼ比例するように設
定して内装し、さらに長軸方向付近の内側のみに
低損失な誘電体層を膜厚が誘電体中の電磁波の波
長の１／４の奇数倍にほぼ比例するように設定し
て内装したことにある（第２発明）。 In addition, in a hollow optical waveguide with an elliptical cross section made of a metal material with a large complex refractive index, a low-loss alternating multilayer dielectric film with two different refractive indexes is uniformly formed in the circumferential direction, and the film thickness is set in the dielectric material. The interior is set so that it is approximately proportional to an odd multiple of 1/4 of the wavelength of the electromagnetic waves in the dielectric, and a low-loss dielectric layer is installed only on the inside near the long axis direction, so that the film thickness is approximately proportional to the wavelength of the electromagnetic waves in the dielectric. This is because the interior is set to be approximately proportional to an odd multiple of 1/4 (second invention).
本発明において、複素屈折率が大きい金属材料
としては、Ag、Au、Cu、Alなどがあげられ、
また内装する低損失誘電体材料としては、ZnSe、
Ge、KCl、CsBrなどのハロゲン化物、あるいは
GeSeやGeTe系ガラスなどがあげられる。 In the present invention, examples of metal materials having a large complex refractive index include Ag, Au, Cu, Al, etc.
In addition, low-loss dielectric materials for the interior include ZnSe,
Halides such as Ge, KCl, CsBr, or
Examples include GeSe and GeTe glass.
第１図は第１発明の光導波路の一実施例の説明
図である。
FIG. 1 is an explanatory diagram of an embodiment of the optical waveguide of the first invention.
１は複素屈折率が大きな金属材料、２は低損失
な誘電体層、３は中空領域である。 1 is a metal material with a large complex refractive index, 2 is a low-loss dielectric layer, and 3 is a hollow region.
中空領域には空気またはこれ以外の低損失気体
が存在しており、また断面の内径は使用波長の
10.6μmに比して十分大きく選ばれている。 Air or other low-loss gas exists in the hollow region, and the inner diameter of the cross section corresponds to the wavelength used.
It is chosen to be sufficiently large compared to 10.6 μm.
いま、電界が長軸方向に偏波したモードについ
て考える。 Now, let us consider a mode in which the electric field is polarized along the long axis.
このとき、短軸方向付近の金属壁面では電界は
金属壁面に対して平行であるため誘電体を内装し
なくとも低損失となる（むしろ、誘電体を内装さ
せた方が高損失となる）。 At this time, since the electric field is parallel to the metal wall surface in the vicinity of the minor axis direction, the loss is low even if no dielectric is provided (in fact, the loss is higher when the dielectric is provided).
ところが、長軸方向付近の金属壁面では電界は
金属壁面に対して垂直であるため誘電体を内装し
ないと高損失となる。電界が金属壁面に対して垂
直な電磁波に対しては、誘電体層２をその膜厚が
誘電体中の電磁波の波長の１／４の奇数倍にほぼ
比例するように設定したとき最も低損失となる。 However, since the electric field is perpendicular to the metal wall surface near the major axis direction, high loss will occur unless a dielectric material is provided inside. For electromagnetic waves in which the electric field is perpendicular to the metal wall surface, the lowest loss is achieved when the dielectric layer 2 is set so that its thickness is approximately proportional to an odd multiple of 1/4 of the wavelength of the electromagnetic waves in the dielectric. becomes.
すなわち、内装誘電体層２の膜厚ｄが短軸方向
ではｄ≒０、長軸方向では
ｄ≒qλ／４（a2−１）1/2
を満足するように設定すればよい。 That is, the film thickness d of the internal dielectric layer 2 may be set so as to satisfy d≈0 in the minor axis direction and d≈qλ/4(a 2 −1) 1/2 in the major axis direction.
ここで、ｑ＝１，３，５，…、λは使用波長、
ａは誘電体の屈折率である。 Here, q=1, 3, 5,..., λ is the wavelength used,
a is the refractive index of the dielectric.
このような膜厚の誘電体層２を内装させたと
き、電界が長軸方向に平行な低損失なモードと、
電界が短軸方向に平行な高損失モードでは伝搬定
数が大きく異なるため、入射側で電界が長軸方向
になるように入射されたモードは偏波が安定に保
たまま伝搬する。 When the dielectric layer 2 with such a thickness is installed, a low-loss mode in which the electric field is parallel to the long axis direction,
Since the propagation constant is significantly different in a high-loss mode in which the electric field is parallel to the minor axis direction, a mode that is incident on the input side so that the electric field is in the major axis direction propagates while the polarization is kept stable.
第２図は第２発明の一実施例の説明図である。
複素屈折率が大きな金属材料２１と低損失誘電体
層２２との間に、それぞれ屈折率の異なる誘電体
層２４，２５を内装させたものであり、このよう
に誘電体層を交互に多数内装させることによりさ
らに低損失な導波路を実現できる。２３は中空領
域である。 FIG. 2 is an explanatory diagram of an embodiment of the second invention.
Dielectric layers 24 and 25 having different refractive indexes are interposed between a metal material 21 having a large complex refractive index and a low-loss dielectric layer 22, and in this way, a large number of dielectric layers are alternately interposed. By doing so, a waveguide with even lower loss can be realized. 23 is a hollow area.
誘電体層２４，２５の膜厚は電磁波の波長の
１／４の奇数倍にほぼ比例するように選ばれてお
り、誘電体層２２の膜厚は短軸方向ではほぼゼ
ロ、長軸方向では誘電体中の電磁波の波長１／４
の奇数倍にほぼ比例するように選ばれている。な
お、この場合誘電体層２５の方が誘電体層２４よ
りも屈折率が小さくされており、例えば誘電体層
２５としてZnSe、誘電体層２４としてGeの組み
合わせ考えられる。 The film thicknesses of the dielectric layers 24 and 25 are selected to be approximately proportional to an odd multiple of 1/4 of the wavelength of the electromagnetic wave, and the film thickness of the dielectric layer 22 is approximately zero in the minor axis direction and approximately zero in the major axis direction. 1/4 wavelength of electromagnetic waves in dielectric material
is chosen so that it is approximately proportional to an odd multiple of . In this case, the dielectric layer 25 has a smaller refractive index than the dielectric layer 24, and for example, a combination of ZnSe for the dielectric layer 25 and Ge for the dielectric layer 24 can be considered.
第２図の実施例では誘電体層が短軸方向では２
層、長軸方向では３層の例を示したが、更に多層
化してもよい。 In the embodiment shown in FIG. 2, the dielectric layer is
Although an example of three layers in the long axis direction has been shown, it may be further layered.
〔発明の効果〕
以上説明してきたとおり、本発明によれば低損
失伝送が可能であり、しかも可撓性を有する中空
光導波路を実現できる。[Effects of the Invention] As described above, according to the present invention, it is possible to realize a hollow optical waveguide that allows low-loss transmission and has flexibility.
第１図は第１発明の一実施例の断面説明図、第
２図は第２発明の一実施例の説明図、第３図は従
来の説明図である。
１，２１：金属材料、２，２２，２４，２５：
誘電体層、２３：中空領域。
FIG. 1 is a cross-sectional explanatory diagram of an embodiment of the first invention, FIG. 2 is an explanatory diagram of an embodiment of the second invention, and FIG. 3 is an explanatory diagram of a conventional device. 1, 21: Metal material, 2, 22, 24, 25:
Dielectric layer, 23: hollow region.
Claims (1)
を有する中空光導波路において、長軸方向付近の
内側のみに低損失な誘電体層を膜厚が誘電体中の
電磁波の波長の１／４の奇数倍にほぼ比例するよ
うに設定して内装したことを特徴とする中空光導
波路。 ２ 複素屈折率が大きな金属材料よりなる楕円断
面を有する中空光導波路において、周方向に一様
に２種類の異なる屈折率をもつ低損失な誘電体交
互多層膜を膜厚がそれぞれ誘電体中の電磁波の波
長の１／４の奇数倍にほぼ比例するように設定し
て内装し、さらに長軸方向付近の内側のみに低損
失な誘電体層を膜厚が誘電体中の電磁波の波長の
１／４の奇数倍にほぼ比例するように設定して内
装したことを特徴とする中空光導波路。[Scope of Claims] 1. In a hollow optical waveguide having an elliptical cross section made of a metal material with a large complex refractive index, a low-loss dielectric layer is provided only on the inside near the major axis direction, and the film thickness corresponds to the wavelength of electromagnetic waves in the dielectric. A hollow optical waveguide characterized in that the interior is set to be approximately proportional to an odd multiple of 1/4 of the waveguide. 2. In a hollow optical waveguide with an elliptical cross section made of a metal material with a large complex refractive index, a low-loss alternating multilayer dielectric film with two different refractive indexes is uniformly formed in the circumferential direction, and the film thickness is the same as that of the dielectric material. The interior is set to be approximately proportional to an odd multiple of 1/4 of the wavelength of the electromagnetic wave, and a low-loss dielectric layer is added only on the inside near the long axis direction, and the film thickness is 1/4 of the wavelength of the electromagnetic wave in the dielectric. A hollow optical waveguide characterized in that the interior is set to be approximately proportional to an odd multiple of /4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60076068A JPS61233705A (en) | 1985-04-10 | 1985-04-10 | Hollow optical waveguide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60076068A JPS61233705A (en) | 1985-04-10 | 1985-04-10 | Hollow optical waveguide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61233705A JPS61233705A (en) | 1986-10-18 |
| JPH0254923B2 true JPH0254923B2 (en) | 1990-11-26 |
Family
ID=13594459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60076068A Granted JPS61233705A (en) | 1985-04-10 | 1985-04-10 | Hollow optical waveguide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61233705A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2663381B2 (en) * | 1988-09-01 | 1997-10-15 | 株式会社町田製作所 | Manufacturing method of hollow waveguide |
| GB0201950D0 (en) * | 2002-01-29 | 2002-03-13 | Qinetiq Ltd | Multimode interference optical waveguide device |
-
1985
- 1985-04-10 JP JP60076068A patent/JPS61233705A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61233705A (en) | 1986-10-18 |
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