JPH03285136A - Measuring apparatus for reflectivity - Google Patents

Abstract

PURPOSE:To perform accurate measurement by simple measuring operation by arranging the cubic beam splitter of a sample and a reference element being an equilateral right-angled prism composed of the same material as the splitter at a measuring position so as to be capable of exchange both of them. CONSTITUTION:A sample C is placed on a sample holder 1 and the output of a light detector 3 at this time is recorded. Next, a reference element 5 is placed on the same region as the sample C so that two right-angled sides thereof are brought into contact with the pad 2 of the holder 1 and the output of the detector 3 at this time is recorded. The transmissivity of the whole of a light path is calculated on the basis of the ratio of the intensity of incident light in the case of the element 5 and that of the light incident to the detector 3. The transmissivity of the whole of the light path in the case of the sample C is same to that in the case of the element because the sample is same to the element 5 in material quality and shape but, since the place of the total reflection surface in the element 5 becomes the light splitting surface of a beam splitter of the reflectivity of the sample C at the time of the sample C, the reflectivity of the sample C is calculated by comparing the intensities of the light incident to the detector 3 in two cases.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は試料の反射率特にキューブ型ビームスブ！ノッ
クの反射率測定装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention is directed to improving the reflectance of a sample, especially for cube-shaped beams! This invention relates to a knock reflectance measuring device.

（従来の技術） 従来キューブ型ビームスプリッタの反射率測定は第３図
に示すような装置を用いて行っていた。(Prior Art) Conventionally, the reflectance of a cube beam splitter has been measured using an apparatus as shown in FIG.

第３図でＣが試料のキューブ型ビームスプリッタ、Ｄは
光検出器で、装置中心Ｐを中心として旋回できるように
なっている。測定はまず試料なしで、光検出器を入射光
の延長線上のＯ位置において、入射光の強度１ｏを測定
し、次に図のように試料Ｃを置き、検出！ｓＤを図の位
置に移動させて試料のビームスブリッ′りＣの反射光の
強度ｌを測定する。このようにして絶対反射率ＲはＲ＝
Ｉ／ｌｏとして求まる。In FIG. 3, C is a cube-shaped beam splitter for the sample, and D is a photodetector, which can be rotated around the center P of the apparatus. To measure, first, without a sample, place the photodetector at position O on the extension line of the incident light and measure the intensity 1o of the incident light.Next, place sample C as shown in the figure and detect! Move sD to the position shown in the figure and measure the intensity l of the reflected light from the beam splitter C of the sample. In this way, the absolute reflectance R is R=
It can be found as I/lo.

（発明が解決しようとする課題） 上述した従来の装置は光検出器を動かすため装置構成が
ゴニオメータ型となり大型で高価な装置となる。光検出
器を動かす必要があるため分光光度計の一つのアタック
メントとして試料室内に設置することが不可能である。(Problems to be Solved by the Invention) The conventional device described above has a goniometer-type device configuration in order to move the photodetector, resulting in a large and expensive device. Since it is necessary to move the photodetector, it is impossible to install it in the sample chamber as an attack part of the spectrophotometer.

更に光検出器を移動するためリード線が長くなり、ノイ
ズを拾い易くなると云う難点もある。更に、光入出射面
の反射損失を含んだ値しか測定できないため、純粋にビ
ームスプリッタ−面の性能だけを評価することは難しい
。Furthermore, since the photodetector is moved, the lead wire becomes long, and there is also the problem that noise is more likely to be picked up. Furthermore, since it is only possible to measure values that include the reflection loss of the light input/output surface, it is difficult to purely evaluate the performance of the beam splitter surface.

本発明は上述したような難点を解消したキューブ型ビー
ムスプリッタの反射率測定装置を提供しようとするもの
である。The present invention aims to provide a reflectance measuring device for a cube beam splitter which eliminates the above-mentioned difficulties.

（課題を解決するための手段） 試料のキューブ型ビームスプリッタの反射光を受光する
ように配置された光検出器と、試料のキューブ型ビーム
スプリッタと同種材料で作られた２等辺直角プリズムの
対照素子とを備え、試料と対照素子とを交換可能に試料
測定位置に設置できるようにした。(Means for solving the problem) Comparison of a photodetector arranged to receive the reflected light from the cube-shaped beam splitter of the sample and an isosceles right-angle prism made of the same material as the cube-shaped beam splitter of the sample. The sample element and the reference element can be exchangeably installed at the sample measurement position.

（作用） 対照用の２等辺直角プリズムを測定位置に置いたとき、
入射光は全反射されて光検出器に入る。(Function) When the isosceles rectangular prism for comparison is placed at the measurement position,
The incident light is totally reflected and enters the photodetector.

入射光の強度をＩｏ、このとき光検出器に入射すはこの
ときの光路全体の透過率を与える。対照素子の代りに試
料のキューブ型ビームスプリッタを置くと、このときの
光路は対照素子と試料が同じ材料で同じ形なので、対照
素子を置いたときと同じで、光路全体の透過率はＴであ
り、対照素子で全反射していた面の所が反射率Ｒのビー
ムスプリッタの光分割面になっただけであり、このＲが
測定しようとするものである。試料を置いたときの光検
出器入射光の光の強度を！とすると、１＝ＩｏＴＲ こ＼でＩｏＴ＝Ｉｏ’で、これは前述したように先に測
定されているので、 Ｒ＝Ｉ／Ｉ。The intensity of the incident light is Io, and the transmittance of the entire optical path at this time when it is incident on the photodetector is given. When a cube-shaped beam splitter for the sample is placed in place of the reference element, the optical path in this case is the same as when the reference element is placed, since the reference element and the sample are made of the same material and have the same shape, and the transmittance of the entire optical path is T. The surface that was undergoing total reflection in the control element has simply become the light splitting surface of the beam splitter with a reflectance R, and this R is what is to be measured. The intensity of the light incident on the photodetector when the sample is placed! Then, 1=IoTR and IoT=Io', which was measured earlier as mentioned above, so R=I/I.

で与えられる。is given by

（実施例） 第１図は本発明の第１の実施例を示す。１は試料ホルダ
で、２は試料位置決め用の当りである。(Embodiment) FIG. 1 shows a first embodiment of the present invention. 1 is a sample holder, and 2 is a hit for positioning the sample.

Ｌは入射光で、３はこの入射光りと直交する方向（こ置
かれた光検出器であり、試料ホルダ１の後方で入射光り
の延長線上に置かれた４は光トラップである。Ｃは試料
のキューブ型ビームスプリッタ、５は対照素子で試料Ｃ
と同種ガラスで作られた２等辺直角プリズムである。対
照素子５は試料のビームスプリッタを対角線で切った半
分の大きさであるのが望ましい。L is the incident light, 3 is a photodetector placed in the direction perpendicular to this incident light, and 4 is a light trap placed on the extension line of the incident light behind the sample holder 1.C is Sample cube beam splitter, 5 is reference element, sample C
It is an isosceles right-angle prism made of the same type of glass. The reference element 5 is preferably half the size of the beam splitter of the sample diagonally.

測定は次のように行う。試料Ｃを図のように試料ホルダ
に置き、そのときの光検出器３の出力■を記録する。次
にＣの所に対照素子５を直角２辺を試料ホルダの当り２
に当接させて置き、そのときの光検出器出力１ｏ’を記
録する。前述した所によって試料Ｃの反射率Ｒは Ｒ＝Ｉ／ｉ。Measurement is carried out as follows. Place the sample C on the sample holder as shown in the figure, and record the output ■ of the photodetector 3 at that time. Next, place the control element 5 at point C, with the two right-angled sides touching the sample holder.
The photodetector output 1o' at that time is recorded. According to the above, the reflectance R of sample C is R=I/i.

で与えられる。is given by

第２図は本発明の第２の実施例である。この実施例では
光検出器３は入射光りの延長線上に設置されており、試
料Ｃ或は対照素子５で反射された光は鏡Ｍ１〜Ｍ３て反
射されて光検出器３に入射せしめられるようになってい
る。鏡Ｍ３の要領には光トラップ４が設けられており、
ｆｉＭ３と光トラップ４とは一体的に図示矢印ａ方向に
Ｐ点を中心に回動可能で、反射率測定時にはそれぞれＭ
３、Ｔの位置にあるものとする。試料ホルダ１も矢印す
方向に移動可能で、試料が大きいときは図鎖線のように
右方にずらせて、反射光が光検出器Ｂに入るようにする
。このときビームスプリッタ−の透過光は光トラップ４
で吸収除去される。試料Ｃ或は対照素子５で反射された
光が光検出器３に入射するまでの光路は前記実施例に比
し複雑であるが、試料に対しても対照素子に対しても全
く同じ光路を提供するから、この光路における透過率の
影響は完全に相殺′されて、前記実施例と同様にして反
射率を求めることができる。FIG. 2 shows a second embodiment of the invention. In this embodiment, the photodetector 3 is installed on the extension line of the incident light, so that the light reflected by the sample C or the control element 5 is reflected by the mirrors M1 to M3 and is made to enter the photodetector 3. It has become. A light trap 4 is installed at the point of the mirror M3,
fiM3 and optical trap 4 can be integrally rotated around point P in the direction of arrow a in the figure, and when measuring reflectance, each
3. Assume that it is in position T. The sample holder 1 is also movable in the direction of the arrow, and when the sample is large, it is shifted to the right as shown by the chain line in the figure so that the reflected light enters the photodetector B. At this time, the transmitted light of the beam splitter is transmitted to the optical trap 4.
is absorbed and removed. Although the optical path of the light reflected by the sample C or the control element 5 until it enters the photodetector 3 is more complicated than in the above embodiment, the optical path is exactly the same for both the sample and the control element. Therefore, the influence of the transmittance on this optical path is completely canceled out, and the reflectance can be determined in the same manner as in the previous embodiment.

なおこの実施例では鏡Ｍ３と光トラップ４を入射光りの
延長線上から退避させ、試料Ｃの透過光を光検出５３に
入射させるようにして透過光強度１′を測定することが
できる。このとき試料Ｃの反射光の方は図録線位置に来
ている光トラップ４により吸収除去される。他方同様に
して試料Ｃを除くと入射光強度１ｏが面接測定できるか
ら、試料Ｃの透過率も測定できろ。このとき更に試料Ｃ
と同種ガラスで同寸法のキューブ（反射面なし）を試料
位置に置いてそのときの透過光強度１゜を測定すると、
試料透過光とこのｉｏ−との比によって試料Ｃの反射面
だけの透過率を純粋に測定することができる。In this embodiment, the mirror M3 and the optical trap 4 are moved away from the extension line of the incident light, and the transmitted light of the sample C is made incident on the photodetector 53, so that the transmitted light intensity 1' can be measured. At this time, the reflected light from the sample C is absorbed and removed by the optical trap 4 located at the chart line position. On the other hand, if sample C is removed in the same manner, the incident light intensity 1o can be measured face-to-face, so the transmittance of sample C can also be measured. At this time, sample C
When a cube of the same size and made of the same type of glass (without a reflective surface) is placed at the sample position and the transmitted light intensity of 1° is measured,
The transmittance of only the reflective surface of sample C can be measured purely by the ratio of the sample transmitted light and this io-.

（発明の効果） 本発明によれば光検出器を旋回させる必要がないから装
置が簡単小型化され、分光光度計の試料室に設置可能と
することも容易となり、また光検出器を動かさないから
ノイズを拾うと云う問題もなくなる。また本発明ではキ
ューブ型ビームスプリッタの反射面そのものの反射率、
透過率が測定でき、キューブの表面反射の影響を受けな
い。従来方法では表面反射の影響が避けられないので試
料表面に反射防止膜をつける等の手段を構じていたので
、本発明によれば、測定操作も簡単となり、かつ正確な
測定ができることになる。(Effects of the Invention) According to the present invention, since there is no need to rotate the photodetector, the device can be easily miniaturized, it can be easily installed in the sample chamber of a spectrophotometer, and the photodetector does not need to be moved. This eliminates the problem of picking up noise from other sources. In addition, in the present invention, the reflectance of the reflecting surface itself of the cube beam splitter,
Transmittance can be measured and is not affected by cube surface reflections. In conventional methods, the influence of surface reflection cannot be avoided, so measures such as attaching an anti-reflection film to the sample surface have been used, but the present invention simplifies the measurement operation and enables accurate measurements. .

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の第１実施例の平面図、第２図は第２実
施例の平面図、第３図は従来例の平面図である。 １・・・試料ホルダ、２・・・位置決め用当り、３・・
・光検出器、４・・・光トラップ、５・・・対照素子。FIG. 1 is a plan view of a first embodiment of the present invention, FIG. 2 is a plan view of a second embodiment, and FIG. 3 is a plan view of a conventional example. 1... Sample holder, 2... Positioning perch, 3...
- Photodetector, 4... Optical trap, 5... Control element.

Claims (1)

【特許請求の範囲】[Claims] 試料ホルダ上に置かれた試料のキューブ型ビームスプリ
ッタの反射光を受光する位置に設置された光検出器と、
試料のキューブ型ビームスプリッタと同種材料で作られ
、試料ホルダ上に試料と交換可能に載置可能な２等辺直
角プリズムの対照素子を備えたことを特徴とする反射率
測定装置。a photodetector installed at a position to receive the reflected light from the cube-shaped beam splitter of the sample placed on the sample holder;
A reflectance measuring device comprising a reference element in the form of an isosceles right angle prism that is made of the same material as the cube beam splitter of the sample and that can be placed on the sample holder so as to be replaceable with the sample.