JPH11287741A - Method for measuring numerical aperture of optical fiber using aperture - Google Patents

Method for measuring numerical aperture of optical fiber using aperture

Info

Publication number
JPH11287741A
JPH11287741A JP10370798A JP10370798A JPH11287741A JP H11287741 A JPH11287741 A JP H11287741A JP 10370798 A JP10370798 A JP 10370798A JP 10370798 A JP10370798 A JP 10370798A JP H11287741 A JPH11287741 A JP H11287741A
Authority
JP
Japan
Prior art keywords
optical fiber
light
aperture
detector
forming member
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.)
Pending
Application number
JP10370798A
Other languages
Japanese (ja)
Inventor
Tetsuya Umemura
哲也 梅村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Furukawa Electric Co Ltd
Original Assignee
Furukawa Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Furukawa Electric Co Ltd filed Critical Furukawa Electric Co Ltd
Priority to JP10370798A priority Critical patent/JPH11287741A/en
Publication of JPH11287741A publication Critical patent/JPH11287741A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To measure the maximum theoretical numerical aperture of an optical fiber easily and accurately. SOLUTION: A detector 6 detects light from a lens 5 and an optical fiber 2 through an aperture forming member 3 having an opening 4 disposed on the exit side of the optical fiber 2. The center of the opening 4 is aligned with the optical axis of the optical fiber 2 and the light receiving part 9 of the detector 6. While varying the angle θ, i.e., one halt of the spreading angle of light passing through the inner wall at the opening from the center at the exit end 8 of the optical fiber 8, by varying the distance between the aperture forming member 3 and the exit end 8 of the optical fiber 8, the quantity of light emitted from the light source 1, passed through the optical fiber 2 and the opening 4 of the aperture forming member 3, and received by the detector 6 is detected. A data representing the relationship between the quantity it received light and sinθis then determined and the maximum theoretical numerical aperture of the optical fiber is determined from the value of sinθ at a point where the increasing quantity of light begins to saturate.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、アパーチャー(開
口部)を形成したアパーチャー形成部材を用いて光ファ
イバの最大理論開口数を測定するアパーチャーを用いた
光ファイバ開口数の測定方法に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the maximum theoretical numerical aperture of an optical fiber using an aperture forming member having an aperture formed therein. .

【0002】[0002]

【従来の技術】光ファイバの開口数の測定方法として
は、周知の如く、RNF(屈折ニアフィールド)法やファ
ーフィールド・スキャニング法などが用いられている。
2. Description of the Related Art As a well-known method for measuring the numerical aperture of an optical fiber, an RNF (refractive near-field) method, a far-field scanning method, and the like are used.

【0003】[0003]

【発明が解決しようとする課題】しかしながら、RNF
法は、測定が複雑で時間がかかるために、例えば光ファ
イバの敷設場所などの作業現場において光ファイバ開口
数を測定するには不向きであり、一方、ファーフィール
ド・スキャニング法は、この方法によって測定される光
ファイバ開口数が「ファーフィールド光強度分布の最大
値の5%位置」と定義されているために、光ファイバの
最大理論開口数(最大理論NA)と2.5%程度の差が
あり、光ファイバの最大理論開口数を正確に測定するこ
とができなかった。
SUMMARY OF THE INVENTION However, RNF
The method is unsuitable for measuring optical fiber numerical aperture at work sites, for example, where optical fiber is laid, because the measurement is complicated and time-consuming, while the far-field scanning method is not Since the numerical aperture of the optical fiber is defined as “5% position of the maximum value of the far-field light intensity distribution”, the difference between the maximum theoretical numerical aperture (maximum theoretical NA) of the optical fiber and about 2.5% is different. Yes, the maximum theoretical numerical aperture of the optical fiber could not be measured accurately.

【0004】本発明は、上記従来の課題を解決するため
になされたものであり、その目的は、例えば光ファイバ
敷設場所などでも容易に、かつ、正確に光ファイバの最
大理論開口数を正確に測定することができるアパーチャ
ーを用いた光ファイバ開口数の測定方法を提供すること
にある。
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to easily and accurately determine the maximum theoretical numerical aperture of an optical fiber, for example, even where an optical fiber is laid. An object of the present invention is to provide a method for measuring the numerical aperture of an optical fiber using an aperture that can be measured.

【0005】[0005]

【課題を解決するための手段】上記目的を達成するため
に、本発明は次のような構成をもって課題を解決するた
めの手段としている。すなわち、本第1の発明は、光フ
ァイバの入射側に光源を配置し、該光ファイバの出射側
には該光ファイバの出射側から出射する光量を検出する
検出器を該光ファイバの出射端と間隔を介して配置し、
該検出器と光ファイバの出射端との間には開口部を形成
して成るアパーチャー形成部材を配置して該アパーチャ
ー形成部材の開口部中心と前記光ファイバの光軸と検出
器の光受信部とが一直線上になるように配置し、該アパ
ーチャー形成部材と光ファイバ出射端との距離を可変す
ることによって光ファイバ出射端の中心点から開口部の
内壁を通る光の広がり角度の1/2の角度θを可変しな
がら前記光源から光ファイバに入射して該光ファイバの
出射端から出射し前記アパーチャー形成部材の開口部を
通って前記検出器に受信される光量を検出し、該光量と
sinθとの関係データを求め、該関係データに基づい
て関係データの光量増加が飽和開始する点におけるsi
nθの値を光ファイバの最大理論開口数とする構成を持
って課題を解決する手段としている。
In order to achieve the above-mentioned object, the present invention has the following structure to solve the problem. That is, according to the first aspect of the present invention, a light source is disposed on the input side of the optical fiber, and a detector for detecting the amount of light emitted from the output side of the optical fiber is provided on the output side of the optical fiber. And place through the spacing,
An aperture forming member having an opening is disposed between the detector and the emission end of the optical fiber, and the center of the opening of the aperture forming member, the optical axis of the optical fiber, and the light receiving portion of the detector are arranged. Are arranged so as to be on a straight line, and by varying the distance between the aperture forming member and the optical fiber output end, the half of the spread angle of light passing through the inner wall of the opening from the center point of the optical fiber output end While changing the angle θ, the light source enters the optical fiber, detects the amount of light emitted from the emission end of the optical fiber, and received by the detector through the opening of the aperture forming member. is obtained at the point where the increase in the amount of light of the related data starts to saturate based on the related data.
This is a means for solving the problem with a configuration in which the value of nθ is set to the maximum theoretical numerical aperture of the optical fiber.

【0006】また、本第2の発明は、光ファイバの入射
側に光源を配置し、該光ファイバの出射側には該光ファ
イバの出射側から出射する光量を検出する検出器を該光
ファイバの出射端と間隔を介して配置し、該検出器と光
ファイバの出射端との間には互いに大きさの異なる複数
の開口部を形成して成るアパーチャー形成部材を配置し
て該アパーチャー形成部材に形成された各開口部中心と
光ファイバ光軸と検出器の光受信部とが一直線状になる
ように順次異なる大きさの開口部を光ファイバ光軸に位
置合わせして、光ファイバ出射端の中心点から開口部の
内壁を通る光の広がり角度の1/2の角度θを可変しな
がら前記光源から光ファイバに入射して該光ファイバの
出射端から出射し前記アパーチャー形成部材の開口部を
通って前記検出器に受信される光量を検出し、該光量と
sinθとの関係データを求め、該関係データに基づい
て関係データの光量増加が飽和開始する点におけるsi
nθの値を光ファイバの最大理論開口数とする構成を持
って課題を解決する手段としている。
According to a second aspect of the present invention, a light source is disposed on the input side of the optical fiber, and a detector for detecting the amount of light emitted from the output side of the optical fiber is provided on the output side of the optical fiber. And an aperture forming member formed by forming a plurality of openings having different sizes from each other between the detector and the emitting end of the optical fiber. The openings of different sizes are sequentially aligned with the optical axis of the optical fiber so that the center of each opening formed in the optical fiber, the optical axis of the optical fiber, and the light receiving section of the detector are aligned, and The light source enters the optical fiber and emits from the emission end of the optical fiber while varying the angle θ of 1 / of the spread angle of the light passing through the inner wall of the opening from the center point of the aperture, and the opening of the aperture forming member. Through the detector Detecting a received the amount of light, obtains the relationship data between the light amount and the sin [theta, light intensity increases in relationship data based on the relationship data at the point of starting saturated si
This is a means for solving the problem with a configuration in which the value of nθ is set to the maximum theoretical numerical aperture of the optical fiber.

【0007】上記構成の本発明において、本第1の発明
においては、アパーチャー形成部材と光ファイバ出射端
との距離を可変し、本第2の発明においては、アパーチ
ャー形成部材に形成された各開口部中心と光ファイバ光
軸と検出器の光受信部とが一直線状になるように順次異
なる大きさの開口部を光ファイバ光軸に位置合わせする
ことにより、本第1、第2のいずれの発明においても、
光ファイバ出射端の中心点から開口部の内壁を通る光の
広がり角度の1/2の角度θを可変しながら、光ファイ
バの出射端から出射してアパーチャー形成部材の開口部
を通り、検出器に受信される光量が検出されて、この光
量とsinθとの関係データが求められる。
In the present invention having the above structure, in the first invention, the distance between the aperture forming member and the optical fiber emitting end is changed, and in the second invention, each of the openings formed in the aperture forming member is changed. By sequentially aligning openings of different sizes with the optical fiber optical axis so that the center of the optical fiber, the optical fiber optical axis, and the light receiving part of the detector are linear, any one of the first and second embodiments can be used. In the invention,
While varying the angle θ of 端 of the spread angle of light passing through the inner wall of the opening from the center point of the optical fiber emitting end, the light is emitted from the emitting end of the optical fiber, passes through the opening of the aperture forming member, and is detected by the detector. Is detected, and relational data between the light amount and sin θ is obtained.

【0008】前記角度θが大きくなると、アパーチャー
形成部材の開口部を通る光量が増えるために、前記検出
器により受信される光量は増加するが、sinθが光フ
ァイバの最大理論開口数を超えると、光ファイバの出射
端から出射する光は最大理論開口数を超えて広がらない
ために、理論的には検出器により受信される光量は増え
ない。なお、実際には、sinθが光ファイバの最大理
論開口数を超えても、外乱光などの影響などで、検出器
により受信される光量は多少増えることになるが、その
増加量は非常に少なく、従って、前記関係データは、s
inθが大きくなるにつれて光量が増え、sinθが光
ファイバの最大理論開口数になると光量増加が飽和し始
めるデータとなる。
When the angle θ increases, the amount of light passing through the aperture of the aperture forming member increases, so the amount of light received by the detector increases. However, when sin θ exceeds the maximum theoretical numerical aperture of the optical fiber, Since the light emitted from the emission end of the optical fiber does not spread beyond the maximum theoretical numerical aperture, the amount of light received by the detector does not theoretically increase. In fact, even if sin θ exceeds the maximum theoretical numerical aperture of the optical fiber, the amount of light received by the detector slightly increases due to the influence of disturbance light or the like, but the increase is extremely small. And therefore the relational data is s
As inθ increases, the amount of light increases. When sinθ reaches the maximum theoretical numerical aperture of the optical fiber, the data starts to saturate the increase in amount of light.

【0009】本発明においては、この関係データに基づ
いて関係データの光量増加が飽和開始する点におけるs
inθの値を光ファイバの最大理論開口数とするため
に、上記のsinθと検出器により受信される光量との
関係から、非常に容易に、かつ、正確に光ファイバの最
大理論開口数を測定することが可能となり、上記課題が
解決される。
In the present invention, s at the point where the increase in the light amount of the related data starts to be saturated based on the related data.
To make the value of inθ the maximum theoretical numerical aperture of the optical fiber, the maximum theoretical numerical aperture of the optical fiber can be measured very easily and accurately from the relationship between sinθ and the amount of light received by the detector. And the above-mentioned problem is solved.

【0010】[0010]

【発明の実施の形態】以下、本発明の実施の形態を図面
に基づいて説明する。図1には、本発明に係るアパーチ
ャーを用いた光ファイバ開口数の測定方法の第1実施形
態例を適用する測定系の一例が示されている。
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a measurement system to which a first embodiment of a method for measuring the numerical aperture of an optical fiber using an aperture according to the present invention is applied.

【0011】同図において、光ファイバ2の入射端7側
に光源1が配置されており、光ファイバ2の出射端8側
には光ファイバ2の出射側から出射する光量を検出する
検出器6が、光ファイバ2の出射端8と間隔を介して配
置されている。検出器6と光ファイバ2の出射端8との
間には、板部材に開口部4を形成して成るアパーチャー
形成部材3と、光ファイバ2の出射端8から出射して開
口部4を通過した光を検出器6の光受信部9に集光する
凸レンズ5が配置されている。また、アパーチャー形成
部材3の開口部4の中心と光ファイバ2の光軸とレンズ
5の中心と検出器6の光受信部9とが一直線上になるよ
うに配置されている。
In FIG. 1, a light source 1 is disposed on an incident end 7 side of an optical fiber 2, and a detector 6 for detecting an amount of light emitted from the exit side of the optical fiber 2 is disposed on an exit end 8 side of the optical fiber 2. Are arranged at an interval from the emission end 8 of the optical fiber 2. An aperture forming member 3 formed by forming an opening 4 in a plate member between the detector 6 and the emission end 8 of the optical fiber 2, and the light is emitted from the emission end 8 of the optical fiber 2 and passes through the opening 4. A convex lens 5 for condensing the light obtained on the light receiving unit 9 of the detector 6 is provided. The center of the opening 4 of the aperture forming member 3, the optical axis of the optical fiber 2, the center of the lens 5, and the light receiving section 9 of the detector 6 are arranged so as to be on a straight line.

【0012】アパーチャー形成部材3には、図示されて
いないアパーチャー移動機構が設けられており、このア
パーチャー移動機構によりアパーチャー形成部材3を図
の矢印A方向に、すなわち、光ファイバ2の光軸と平行
な方向に移動させるようになっており、アパーチャー形
成部材3はムーバルアパーチャーと成している。
The aperture forming member 3 is provided with an aperture moving mechanism (not shown). The aperture moving member 3 moves the aperture forming member 3 in the direction of arrow A in the figure, that is, parallel to the optical axis of the optical fiber 2. The aperture forming member 3 is a movable aperture.

【0013】本実施形態例では、図1に示す測定系にお
いて、アパーチャー移動機構によるアパーチャー形成部
材3の移動により、図2に示すように、アパーチャー形
成部材3と光ファイバ2の出射端8との距離を可変し、
光ファイバ出射端8の中心点から開口部4の内壁10を
通る光の広がり角度の1/2の角度θを、例えばθa,
θb,θcのように可変するようにしている。そして、
このように、角度θを可変しながら、光源1から光ファ
イバ2に入射して光ファイバ2の出射端8から出射し、
アパーチャー形成部材3の開口部4を通って検出器6に
受信される光量を検出器6によって検出するようになっ
ている。
In this embodiment, in the measuring system shown in FIG. 1, the movement of the aperture forming member 3 by the aperture moving mechanism causes the aperture forming member 3 and the emission end 8 of the optical fiber 2 to move as shown in FIG. Variable distance,
An angle θ of 広 が り of the spread angle of light passing through the inner wall 10 of the opening 4 from the center point of the optical fiber emitting end 8 is, for example, θa,
It is made to be variable like θb, θc. And
Thus, while varying the angle θ, the light enters the optical fiber 2 from the light source 1 and exits from the emission end 8 of the optical fiber 2,
The detector 6 detects the amount of light received by the detector 6 through the opening 4 of the aperture forming member 3.

【0014】本実施形態例のアパーチャーを用いた光フ
ァイバ開口数の測定方法は、以上のように構成されてい
る測定系を用いて、検出器6によって検出される検出光
量とsinθとの関係データを求める。
The method of measuring the numerical aperture of an optical fiber using the aperture according to this embodiment is based on the relational data between the amount of light detected by the detector 6 and sin θ using the measurement system configured as described above. Ask for.

【0015】そうすると、角度θが大きくなるにつれ
て、すなわち、例えば図2に示すように、アパーチャー
形成部材3が図のcの位置からbの位置に移動し、さら
に、aの位置に移動して光ファイバ2の出射端8に近づ
いていき、角度θがθc→θb→θaとなるにつれて、
アパーチャー形成部材3の開口部4を通る光量が増える
ために、検出器6により受信される光量は増加するが、
sinθが光ファイバ2の最大理論開口数を超えると、
光ファイバ2の出射端8から出射する光の広がりが最大
理論開口数を超えた角度には広がらないために、理論的
には検出器6により受信される光量は増えない。なお、
実際には、sinθが光ファイバの最大理論開口数を超
えても、外乱光などの影響などで、検出器6により受信
される光量は多少増えることになるが、その増加量は非
常に少ない。
Then, as the angle θ increases, that is, as shown in FIG. 2, for example, the aperture forming member 3 moves from the position c in FIG. 2 to the position b, and further moves to the position a in FIG. Approaching the emission end 8 of the fiber 2, and as the angle θ becomes θc → θb → θa,
Since the amount of light passing through the opening 4 of the aperture forming member 3 increases, the amount of light received by the detector 6 increases.
When sin θ exceeds the maximum theoretical numerical aperture of the optical fiber 2,
Since the spread of the light emitted from the emission end 8 of the optical fiber 2 does not spread to an angle exceeding the maximum theoretical numerical aperture, the amount of light received by the detector 6 does not theoretically increase. In addition,
Actually, even if sin θ exceeds the maximum theoretical numerical aperture of the optical fiber, the amount of light received by the detector 6 slightly increases due to the influence of disturbance light or the like, but the increase is very small.

【0016】従って、前記関係データは、例えば図3に
示すように、sinθが大きくなるにつれて光量(受光
量)が増え、sinθが光ファイバ2の最大理論開口数
になると光量増加が飽和し始めるデータとなる。そこ
で、本実施形態例では、このような関係データに基づい
て、関係データの光量増加が飽和開始する点におけるs
inθの値を光ファイバの最大理論開口数とすることに
より、光ファイバ2の最大理論開口数を測定することに
した。なお、関係データの光量増加が飽和開始する点
は、同図に示すように、データ曲線の光量増加領域にお
ける接線s1と飽和領域における接線s2との交点Aと
した。
Therefore, as shown in FIG. 3, for example, as shown in FIG. 3, the amount of light (the amount of received light) increases as sin θ increases, and the increase in the amount of light begins to saturate when sin θ reaches the maximum theoretical numerical aperture of the optical fiber 2. Becomes Therefore, in the present embodiment, based on such relational data, s at the point where the increase in the light amount of the relational data starts to be saturated.
By determining the value of inθ as the maximum theoretical numerical aperture of the optical fiber, the maximum theoretical numerical aperture of the optical fiber 2 was measured. The point at which the increase in the light amount of the related data starts to be saturated is defined as the intersection A of the tangent line s1 in the light amount increase region and the tangent line s2 in the saturation region of the data curve, as shown in FIG.

【0017】本実施形態例によれば、以上のように、開
口部4を形成してなるアパーチャー形成部材3を光ファ
イバ2の光軸と平行な方向に移動させることにより、前
記角度θを可変しながら、光ファイバ2の出射端8から
出射してアパーチャー形成部材3の開口部4を通って検
出器6に受信される光量を測定するといった非常に簡単
な測定を行なうことにより、正確に光ファイバ2の最大
理論開口数を測定することができる。そのため、例えば
光ファイバ2の敷設場所などにおいても本実施形態例を
適用することが可能であり、非常に簡単に、かつ、正確
に光ファイバの最大理論開口数を測定することができ
る。
According to this embodiment, as described above, the angle θ is made variable by moving the aperture forming member 3 formed with the opening 4 in a direction parallel to the optical axis of the optical fiber 2. Meanwhile, by performing a very simple measurement such as measuring the amount of light emitted from the emission end 8 of the optical fiber 2 and received by the detector 6 through the opening 4 of the aperture forming member 3, accurate light The maximum theoretical numerical aperture of the fiber 2 can be measured. Therefore, for example, the present embodiment can be applied to a place where the optical fiber 2 is laid, and the maximum theoretical numerical aperture of the optical fiber can be measured very easily and accurately.

【0018】図4には、本発明に係るアパーチャーを用
いた光ファイバ開口数の測定方法の第2実施形態例を適
用する測定系の一例が示されている。同図において、図
1の測定系と同一名称部分には同一符号が付してあり、
図4に示す測定系は図1に示した測定系とほぼ同様に構
成されているので、その重複説明は省略する。
FIG. 4 shows an example of a measuring system to which the second embodiment of the optical fiber numerical aperture measuring method using the aperture according to the present invention is applied. In the figure, the same reference numerals are given to the same parts as those of the measurement system of FIG.
Since the measurement system shown in FIG. 4 is configured in substantially the same manner as the measurement system shown in FIG. 1, the duplicate description will be omitted.

【0019】図4に示す測定系が図1に示した測定系と
異なる特徴的なことは、図5に示すように、アパーチャ
ー形成部材3を、円盤状の板部材に互いに大きさの異な
る複数の開口部4(4a〜4g)を同心円状に配設した
バリアブルアパーチャーとし、このバリアブルアパーチ
ャーをアパーチャー移動機構(図示せず)によって、図
5に示すように、アパーチャー形成部材3の中心11を
回転軸として回転させるようにしたことである。
The characteristic feature of the measuring system shown in FIG. 4 that is different from the measuring system shown in FIG. 1 is that, as shown in FIG. 5, a plurality of aperture-forming members 3 are formed on a disc-shaped plate member. The apertures 4 (4a to 4g) are concentrically arranged as a variable aperture, and the variable aperture is rotated by an aperture moving mechanism (not shown) to rotate the center 11 of the aperture forming member 3 as shown in FIG. This is to rotate as an axis.

【0020】本実施形態例では、このようなアパーチャ
ー形成部材3の回転により、アパーチャー形成部材3に
形成された各開口部4a〜4gの中心と光ファイバ2の
光軸とレンズ5の中心と検出器6の光受信部9とが一直
線状になるように、順次異なる大きさの開口部4a〜4
gを光ファイバ2の光軸に位置合わせして、光ファイバ
2の出射端8の中心点から開口部4の内壁10を通る光
の広がり角度の1/2の角度θを可変するようにした。
そして、このように、角度θを可変しながら光源1から
光ファイバ2に入射して光ファイバ2の出射端8から出
射し、アパーチャー形成部材3の開口部4を通って検出
器6に受信される光量を検出し、この検出光量とsin
θとの関係データを求めるようにした。なお、このよう
にして求めた関係データの一例を図6に示す。
In this embodiment, the rotation of the aperture forming member 3 detects the center of each of the openings 4a to 4g formed in the aperture forming member 3, the optical axis of the optical fiber 2, and the center of the lens 5. Openings 4a to 4c of sequentially different sizes so that the optical receiver 9 of the detector 6 is linear.
g is aligned with the optical axis of the optical fiber 2, and the angle θ of 広 が り of the spread angle of light passing through the inner wall 10 of the opening 4 from the center point of the emission end 8 of the optical fiber 2 is varied. .
As described above, the light enters the optical fiber 2 from the light source 1 while changing the angle θ, exits from the emission end 8 of the optical fiber 2, passes through the opening 4 of the aperture forming member 3, and is received by the detector 6. And the detected light quantity and sin
The relationship data with θ was obtained. FIG. 6 shows an example of the relation data thus obtained.

【0021】本実施形態例でも、この関係データに基づ
き、上記第1実施形態例と同様にして、関係データの光
量増加が飽和開始する点におけるsinθの値を光ファ
イバの最大理論開口数とすることにより、光ファイバ2
の最大理論開口数を測定することにした。
In this embodiment, the value of sin θ at the point where the increase in the amount of light of the relation data starts to be saturated is defined as the maximum theoretical numerical aperture of the optical fiber in the same manner as in the first embodiment. The optical fiber 2
Was determined to be the maximum theoretical numerical aperture.

【0022】本実施形態例によれば、互いに異なる大き
さの複数の開口部4a〜4gを形成したアパーチャー形
成部材3を回転させさせることにより、前記角度θを可
変しながら、光ファイバ2の出射端8から出射してアパ
ーチャー形成部材3の開口部4を通って検出器6に受信
される光量を測定するといった非常に簡単な測定を行な
うことにより、上記第1実施形態例と同様に、正確に光
ファイバ2の最大理論開口数を測定することができ、例
えば光ファイバ2の敷設場所などにおいて本実施形態例
を適用することにより、非常に簡単に、かつ、正確に光
ファイバの最大理論開口数を測定することができる。
According to the present embodiment, by rotating the aperture forming member 3 in which the plurality of openings 4a to 4g having different sizes are formed, the output of the optical fiber 2 is changed while the angle θ is varied. By performing a very simple measurement, such as measuring the amount of light emitted from the end 8 and received by the detector 6 through the opening 4 of the aperture forming member 3, accurate measurement can be performed in the same manner as in the first embodiment. The maximum theoretical numerical aperture of the optical fiber 2 can be measured at a time. For example, by applying the present embodiment at a place where the optical fiber 2 is laid, the maximum theoretical numerical aperture of the optical fiber 2 can be very easily and accurately calculated. The number can be measured.

【0023】なお、本発明は上記実施形態例に限定され
ることはなく様々な実施の態様を採り得る。例えば、上
記第2実施形態例では、アパーチャー形成部材3に7個
の互いに大きさの異なる開口部4a〜4gを設けてバリ
アブルアパーチャーとしたが、アパーチャー形成部材3
をバリアブルアパーチャーとするときに、開口部4の個
数や大きさなどは特に限定されるものでなく、アパーチ
ャー形成部材3の配設位置において光ファイバ2の最大
理論開口数で出射した光の一部が通過できる大きさの開
口部4と前記光が全て通過できる大きさの開口部4をそ
れぞれ複数形成すればよく、開口部4の大きさや個数は
適宜設定されるものである。
The present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in the above-described second embodiment, the aperture forming member 3 is provided with seven openings 4a to 4g having different sizes from each other to form a variable aperture.
Is a variable aperture, the number and size of the openings 4 are not particularly limited, and a part of the light emitted at the maximum theoretical numerical aperture of the optical fiber 2 at the position where the aperture forming member 3 is disposed. It suffices to form a plurality of openings 4 each having a size through which the light can pass, and a plurality of openings 4 each having a size through which all the light can pass. The size and number of the openings 4 are appropriately set.

【0024】また、上記第2実施形態例では、アパーチ
ャー形成部材3を複数の開口部4a〜4gが同心円状に
配設された円盤状のバリアブルアパーチャーとし、この
バリアブルアパーチャーを回転することにより、アパー
チャー形成部材3に形成されている互いに大きさが異な
る開口部4a〜4gを光ファイバ2の光軸と位置合わせ
するようにしたが、アパーチャー形成部材3を、例えば
互いに大きさが異なる複数の開口部4を直線上に配設し
た板部材により形成し、この板部材を直線的に進退移動
させることによって大きさの異なる各開口部4を光ファ
イバ2の光軸と位置合わせするようにしてもよい。この
ように、各開口部4の配設状態や、アパーチャー形成部
材3の移動方法は特に限定されるものではなく、適宜設
定されるものである。
In the second embodiment, the aperture forming member 3 is a disk-shaped variable aperture in which a plurality of openings 4a to 4g are concentrically arranged, and the aperture is rotated by rotating the variable aperture. The openings 4a to 4g having different sizes formed in the forming member 3 are aligned with the optical axis of the optical fiber 2. However, the aperture forming member 3 is formed by, for example, a plurality of openings having different sizes. 4 may be formed by a plate member arranged on a straight line, and the opening portions 4 having different sizes may be aligned with the optical axis of the optical fiber 2 by linearly moving the plate member. . As described above, the arrangement state of each opening 4 and the method of moving the aperture forming member 3 are not particularly limited, and are appropriately set.

【0025】さらに、上記各実施形態例では、アパーチ
ャー形成部材3はいずれも板部材により形成したが、ア
パーチャー形成部材3は必ずしも板部材により形成する
とは限らず、開口部4が形成されていれば例えば棒状の
部材によって形成してもよい。
Further, in each of the above embodiments, the aperture forming member 3 is formed of a plate member. However, the aperture forming member 3 is not necessarily formed of a plate member. For example, it may be formed by a rod-shaped member.

【0026】[0026]

【発明の効果】本発明によれば、開口部を形成したアパ
ーチャー形成部材の開口部中心と光ファイバ光軸と光フ
ァイバから出射して開口部を通る光を受信する検出器の
光受信部とが一直線上になるように配置し、本第1の発
明においては、アパーチャー形成部材と光ファイバ出射
端との距離を可変し、本第2の発明においては、アパー
チャー形成部材に形成した互いに異なる大きさの各開口
部中心を光ファイバ光軸と順次位置合わせすることによ
り、光ファイバ出射端の中心点から開口部の内壁を通る
光の広がり角度の1/2の角度θを可変しながら前記検
出器の検出光量を測定することでsinθと光量との関
係データを求め、この関係データの光量増加が飽和開始
する点におけるsinθの値を光ファイバの最大理論開
口数とするものであるから、非常に容易に、かつ、正確
に光ファイバの最大理論開口数を測定することができ
る。
According to the present invention, the center of the opening of the aperture forming member having the opening, the optical axis of the optical fiber, and the light receiving portion of the detector for receiving light emitted from the optical fiber and passing through the opening are provided. Are arranged so as to be on a straight line. In the first aspect of the present invention, the distance between the aperture forming member and the optical fiber emitting end is changed. In the second aspect of the present invention, different sizes are formed on the aperture forming member. The center of each aperture is sequentially aligned with the optical axis of the optical fiber, so that the angle θ of 広 が り of the spread angle of light passing through the inner wall of the aperture from the center point of the optical fiber output end can be varied while detecting the angle. The relational data between sin θ and the light quantity is obtained by measuring the light quantity detected by the detector, and the value of sin θ at the point where the increase in the light quantity in this relational data starts to be saturated is defined as the maximum theoretical numerical aperture of the optical fiber. From very easily, and it is possible to measure the maximum theoretical numerical aperture of precise optical fiber.

【0027】そのため、例えば光ファイバの敷設場所な
どにおいても本実施形態例を適用することも可能であ
り、非常に簡単に、かつ、正確に光ファイバの最大理論
開口数を測定することができる。
Therefore, the present embodiment can be applied to, for example, a place where an optical fiber is laid, and the maximum theoretical numerical aperture of the optical fiber can be measured very easily and accurately.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明に係るアパーチャーを用いた光ファイバ
開口数の測定方法の第1実施形態例を適用する測定系の
一例示す要部構成図である。
FIG. 1 is a main part configuration diagram showing an example of a measurement system to which a first embodiment of an optical fiber numerical aperture measuring method using an aperture according to the present invention is applied.

【図2】図1に示す測定系を用いて光ファイバ開口数を
測定するときのアパーチャー形成部材3の移動動作とこ
の移動に伴うsinθ可変動作を示す説明図である。
FIG. 2 is an explanatory view showing a movement operation of the aperture forming member 3 and a sin θ variable operation accompanying the movement when measuring the optical fiber numerical aperture using the measurement system shown in FIG.

【図3】図1の測定系を用いて作製したsinθと検出
器の受光量との関係データを示すグラフである。
FIG. 3 is a graph showing relational data between sin θ and the amount of light received by a detector manufactured using the measurement system of FIG. 1;

【図4】本発明に係るアパーチャーを用いた光ファイバ
開口数の測定方法の第2実施形態例を適用する測定系の
一例示す要部構成図である。
FIG. 4 is a main part configuration diagram showing an example of a measurement system to which a second embodiment of the optical fiber numerical aperture measuring method using the aperture according to the present invention is applied.

【図5】図4に示す測定系に用いられるアパーチャー形
成部材3を示す説明図である。
FIG. 5 is an explanatory view showing an aperture forming member 3 used in the measurement system shown in FIG.

【図6】図4の測定系を用いて作製したsinθと検出
器の受光量との関係データを示すグラフである。
FIG. 6 is a graph showing relational data between sin θ and the amount of light received by a detector manufactured using the measurement system of FIG. 4;

【符号の説明】[Explanation of symbols]

1 光源 2 光ファイバ 3 アパーチャー形成部材 4,4a〜4g 開口部 5 レンズ 6 検出器 8 出射端 9 光受信部 DESCRIPTION OF SYMBOLS 1 Light source 2 Optical fiber 3 Aperture forming member 4, 4a-4g Opening 5 Lens 6 Detector 8 Outgoing end 9 Light receiving part

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 光ファイバの入射側に光源を配置し、該
光ファイバの出射側には該光ファイバの出射側から出射
する光量を検出する検出器を該光ファイバの出射端と間
隔を介して配置し、該検出器と光ファイバの出射端との
間には開口部を形成して成るアパーチャー形成部材を配
置して該アパーチャー形成部材の開口部中心と前記光フ
ァイバの光軸と検出器の光受信部とが一直線上になるよ
うに配置し、該アパーチャー形成部材と光ファイバ出射
端との距離を可変することによって光ファイバ出射端の
中心点から開口部の内壁を通る光の広がり角度の1/2
の角度θを可変しながら前記光源から光ファイバに入射
して該光ファイバの出射端から出射し前記アパーチャー
形成部材の開口部を通って前記検出器に受信される光量
を検出し、該光量とsinθとの関係データを求め、該
関係データに基づいて関係データの光量増加が飽和開始
する点におけるsinθの値を光ファイバの最大理論開
口数とすることを特徴とするアパーチャーを用いた光フ
ァイバ開口数の測定方法。
1. A light source is arranged on the input side of an optical fiber, and a detector for detecting the amount of light emitted from the output side of the optical fiber is provided on the output side of the optical fiber via an interval from the output end of the optical fiber. And an aperture forming member having an opening formed between the detector and the emission end of the optical fiber. The center of the opening of the aperture forming member, the optical axis of the optical fiber, and the detector The light receiving portion is arranged so as to be on a straight line, and by varying the distance between the aperture forming member and the optical fiber emitting end, the spread angle of light passing through the inner wall of the opening from the center point of the optical fiber emitting end. 1/2 of
While changing the angle θ, the light source enters the optical fiber, detects the amount of light emitted from the emission end of the optical fiber, and received by the detector through the opening of the aperture forming member. an optical fiber aperture using an aperture, wherein the value of sin θ at the point where the increase in the amount of light of the relevant data starts to saturate is determined as the maximum theoretical numerical aperture of the optical fiber based on the relational data. How to measure numbers.
【請求項2】 光ファイバの入射側に光源を配置し、該
光ファイバの出射側には該光ファイバの出射側から出射
する光量を検出する検出器を該光ファイバの出射端と間
隔を介して配置し、該検出器と光ファイバの出射端との
間には互いに大きさの異なる複数の開口部を形成して成
るアパーチャー形成部材を配置して該アパーチャー形成
部材に形成された各開口部中心と光ファイバ光軸と検出
器の光受信部とが一直線状になるように順次異なる大き
さの開口部を光ファイバ光軸に位置合わせして、光ファ
イバ出射端の中心点から開口部の内壁を通る光の広がり
角度の1/2の角度θを可変しながら前記光源から光フ
ァイバに入射して該光ファイバの出射端から出射し前記
アパーチャー形成部材の開口部を通って前記検出器に受
信される光量を検出し、該光量とsinθとの関係デー
タを求め、該関係データに基づいて関係データの光量増
加が飽和開始する点におけるsinθの値を光ファイバ
の最大理論開口数とすることを特徴とするアパーチャー
を用いた光ファイバ開口数の測定方法。
2. A light source is disposed on the input side of the optical fiber, and a detector for detecting the amount of light emitted from the output side of the optical fiber is provided on the output side of the optical fiber via an interval from the output end of the optical fiber. Aperture forming members formed by forming a plurality of openings having different sizes between the detector and the emission end of the optical fiber, and each opening formed in the aperture forming member The openings of different sizes are sequentially aligned with the optical fiber optical axis so that the center, the optical fiber optical axis, and the optical receiver of the detector are linear, and the opening of the opening from the center point of the optical fiber output end is adjusted. While changing the angle θ of 広 が り of the light spread through the inner wall, the light enters the optical fiber from the light source, exits from the exit end of the optical fiber, passes through the opening of the aperture forming member, and passes to the detector. Detects the amount of light received The relationship data between the light quantity and sin θ is obtained, and the value of sin θ at the point where the increase in the light quantity of the relation data starts to be saturated is set as the maximum theoretical numerical aperture of the optical fiber based on the relation data. How to measure the optical fiber numerical aperture.
JP10370798A 1998-03-31 1998-03-31 Method for measuring numerical aperture of optical fiber using aperture Pending JPH11287741A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10370798A JPH11287741A (en) 1998-03-31 1998-03-31 Method for measuring numerical aperture of optical fiber using aperture

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10370798A JPH11287741A (en) 1998-03-31 1998-03-31 Method for measuring numerical aperture of optical fiber using aperture

Publications (1)

Publication Number Publication Date
JPH11287741A true JPH11287741A (en) 1999-10-19

Family

ID=14361219

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10370798A Pending JPH11287741A (en) 1998-03-31 1998-03-31 Method for measuring numerical aperture of optical fiber using aperture

Country Status (1)

Country Link
JP (1) JPH11287741A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2604992A2 (en) 2011-12-15 2013-06-19 Draka Comteq B.V. A method for the characterization of optical properties of an optical fiber
CN103558011A (en) * 2013-10-23 2014-02-05 国家电网公司 Experimental device for measuring numerical apertures and attenuation coefficients of light-guide fibers
CN104535177A (en) * 2014-12-29 2015-04-22 苏州优谱德精密仪器科技有限公司 Detection device for measuring near-infrared light numerical aperture

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2604992A2 (en) 2011-12-15 2013-06-19 Draka Comteq B.V. A method for the characterization of optical properties of an optical fiber
US8547541B2 (en) 2011-12-15 2013-10-01 Draka Comteq B.V. Method for the characterization of optical properties of an optical fiber
CN103558011A (en) * 2013-10-23 2014-02-05 国家电网公司 Experimental device for measuring numerical apertures and attenuation coefficients of light-guide fibers
CN104535177A (en) * 2014-12-29 2015-04-22 苏州优谱德精密仪器科技有限公司 Detection device for measuring near-infrared light numerical aperture

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