JPH06229910A - Measuring method for retardation - Google Patents
Measuring method for retardationInfo
- Publication number
- JPH06229910A JPH06229910A JP36056792A JP36056792A JPH06229910A JP H06229910 A JPH06229910 A JP H06229910A JP 36056792 A JP36056792 A JP 36056792A JP 36056792 A JP36056792 A JP 36056792A JP H06229910 A JPH06229910 A JP H06229910A
- Authority
- JP
- Japan
- Prior art keywords
- sample
- retardation
- wave plate
- optical axis
- wavelength plate
- 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
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は複屈折性試料のレターデ
ーションを測定する方法に関する。FIELD OF THE INVENTION The present invention relates to a method for measuring the retardation of a birefringent sample.
【０００２】[0002]
【従来の技術】レターデーションの測定方法として、偏
光子と検光子を光学軸を平行にして、その間に試料を置
き、試料を回転させて、これら三者を透過した光の強度
の試料回転角に対する変化を測定し、計算によってレタ
ーデーションを求める方法が用いられる。この場合透過
光強度を極座標を用い、試料回転角を角度座標にとって
記録すると、一般に十字花形の曲線が得られ、その図形
の最大半径と最小半径との比からレターデーションを算
出するのであるが、レターデーションが試料を透過した
直交２偏光の位相差角で表して２πの整数倍に近い場合
は上記した十字花形の曲線は円に近い形となり、最大半
径と最小半径を正確に求めることが困難となり、レター
デーションを正確に求めることが困難となる。2. Description of the Related Art As a method of measuring retardation, a polarizer and an analyzer have their optical axes parallel to each other, a sample is placed between them, and the sample is rotated. The method of measuring the change with respect to and calculating the retardation is used. In this case, when the transmitted light intensity is used in polar coordinates and the sample rotation angle is recorded in angular coordinates, a cross flower curve is generally obtained, and the retardation is calculated from the ratio of the maximum radius and the minimum radius of the figure. When the retardation is represented by the phase difference angle of two orthogonally polarized light transmitted through the sample and is close to an integer multiple of 2π, the cross flower curve described above becomes a shape close to a circle, and it is difficult to accurately determine the maximum radius and the minimum radius. Therefore, it becomes difficult to accurately obtain the retardation.
【０００３】このため、そのような場合に対して、試料
に１／４波長板を重ねて、試料と１／４位相板を合わせ
た層のレターデーションを測定すると云う方法が提案さ
れた。しかしこの方法は試料の光学軸と１／４波長板の
光学軸とを方向を一致させて重ねる必要があるので、試
料の光学軸の方向が予め判明しているときはよいが、不
明の場合は先ず試料の光学軸の方向を求めておく必要が
ある。試料の光学軸の方向は前述した十字花形の透過光
強度の記録曲線で、一つの最大直径の方向と、それと直
交するもう一つの最大直径の方向であるが、今問題にし
ている十字花形の透過光強度の記録曲線が円に近い場合
は、この二つの最大直径の方向を正確に決めることが困
難であるため、１／４波長板を重ねると云う方法の適用
が困難となる。Therefore, in such a case, a method has been proposed in which a quarter wave plate is overlaid on the sample and the retardation of the layer including the sample and the quarter wave plate is measured. However, this method requires that the optical axis of the sample and the optical axis of the quarter-wave plate be overlapped with their directions aligned, so it is good when the direction of the optical axis of the sample is known in advance, but when it is unknown First, it is necessary to obtain the direction of the optical axis of the sample. The direction of the optical axis of the sample is the recording curve of the transmitted light intensity of the cross flower shape described above, and there is one direction of the maximum diameter and the direction of the other maximum diameter orthogonal to it. When the recording curve of transmitted light intensity is close to a circle, it is difficult to accurately determine the directions of these two maximum diameters, and it is difficult to apply the method of stacking quarter-wave plates.
【０００４】また２軸性複屈折を呈する試料の３軸方向
の屈折率を測定する場合、試料を一つの光学軸を軸とし
て傾けて、レターデーションを測定し、試料の傾き角と
レターデーションとの関係から３軸方向の各屈折率を求
める方法が提案されているが、上述したようなレターデ
ーションが位相差角で２πの整数倍である場合、二つの
光学軸の方向を正確に決定することが困難なため、３軸
方向の屈折率を正確に求めることが困難である。When measuring the refractive index in the triaxial direction of a sample exhibiting biaxial birefringence, the sample is tilted about one optical axis to measure the retardation, and the tilt angle and retardation of the sample are measured. Although a method for obtaining the respective refractive indices in the three-axis directions has been proposed based on the relationship of 1., when the retardation as described above is an integral multiple of 2π in the phase difference angle, the directions of the two optical axes are accurately determined. Therefore, it is difficult to accurately obtain the refractive index in the triaxial directions.
【０００５】[0005]
【発明が解決しようとする課題】本発明は試料のレター
デーションが位相差角で２πの整数倍に近い場合に、試
料の光学軸の方向を正確に検出する方法を提供し、この
ような場合の複屈折の測定の精度向上を計るものであ
る。The present invention provides a method for accurately detecting the direction of the optical axis of a sample when the retardation of the sample is close to an integer multiple of 2π in the phase difference angle. The accuracy of the birefringence measurement is improved.
【０００６】[0006]
【課題を解決するための手段】試料と適宜の波長板を重
ねて、偏光子と検光子との間に置き、試料と波長板とを
重ねたものを回転させて、透過光強度の最大と最小を求
める動作を、試料に対する波長板の方位を代えながら繰
り返し、試料と波長板との合成レターデーションが最大
になる波長板の方向を求める。[Means for Solving the Problems] A sample and an appropriate wave plate are overlapped with each other and placed between a polarizer and an analyzer, and the sample and the wave plate are overlapped with each other to rotate so that the maximum transmitted light intensity is obtained. The operation for obtaining the minimum is repeated while changing the orientation of the wave plate with respect to the sample, and the direction of the wave plate that maximizes the combined retardation of the sample and the wave plate is obtained.
【０００７】[0007]
【作用】試料と波長板とを重ねたときの合成レターデー
ションは試料と波長板の光学軸を進相軸同士，遅相軸同
士合わせたときは、両方の板のレターデーションの単純
和で、このとき最大であり、進相軸と延相軸を合わせた
ときはレターデーションは単純差となる。今考えている
のは試料のレターデーションが２πの整数倍の近くなの
で、１／４波長板を重ねたとき、重ね方向を変えて行く
と、レターデーションは約＋π／４から−π／４の範囲
で変化する。従って波長板を試料に対して回転させなが
ら、レターデーションが最大になる方向を探せば、試料
と波長板の光学軸が一致したことになり、波長板の光学
軸の方向が予め分かっているから、試料の光学軸の方向
も分かる。[Function] The synthetic retardation when the sample and the wave plate are superposed is the simple sum of the retardation of both the plates when the optical axes of the sample and the wave plate are aligned with each other in the fast axis and the slow axis. It is the maximum at this time, and the retardation becomes a simple difference when the fast axis and the slow axis are aligned. What I am thinking now is that the retardation of the sample is close to an integral multiple of 2π, so when the 1/4 wavelength plates are stacked, the retardation will change from approximately + π / 4 to -π / 4 when the stacking direction is changed. Varies with range. Therefore, if the retardation is maximized while rotating the wave plate with respect to the sample, the optical axes of the sample and the wave plate coincide, and the direction of the optical axis of the wave plate is known in advance. , The direction of the optical axis of the sample is also known.
【０００８】[0008]
【実施例】図１は本発明方法を実施する装置の一例を示
す。この実施例では試料を回す代わりに偏光子と検光子
とを一体的に回転させるようになっている。図で１が偏
光子，２が検光子で、これらは同一軸線上に上下に配置
された回転台１１，１２上に取付けられており、各回転
台１１，１２はベルト３を介してパルスモータ４により
同時に同じ角速度で回転せしめられるようになってい
る。偏光子１，検光子２は相互に偏光方向が平行である
ように各回転台上に取付けられている。Ｓは試料で上下
の回転台１１，１２の間に設置される。偏光子１の上方
で５はフィルタであり、特定の波長の光を透過する。６
は光源のハロゲンランプで光ファイバー７を通してフィ
ルタ５上に導かれ、フィルタ透過光が偏光子１，試料
Ｓ，検光子２を透過して受光素子８で検出されるように
なっている。受光素子８の出力は増幅器９を通してデー
タ処理装置１０に送られる。データ処理装置１０からは
パルス信号が発せられ、モータ駆動回路１３に入力さ
れ、モータ駆動パルスに変換されてモータ４に入力され
る。データ処理装置はこのパルスを計数して偏光子，検
光子の回転角を検知している。回転台１１と試料Ｓとの
間に１／４波長板１４が回転可能に挿入されている。1 shows an example of an apparatus for carrying out the method of the present invention. In this embodiment, the polarizer and the analyzer are integrally rotated instead of rotating the sample. In the figure, reference numeral 1 is a polarizer, and 2 is an analyzer, which are mounted on turntables 11 and 12 which are vertically arranged on the same axis, and each turntable 11 and 12 is a pulse motor via a belt 3. By 4 it is possible to rotate at the same angular velocity at the same time. The polarizer 1 and the analyzer 2 are mounted on each rotary table so that the polarization directions are parallel to each other. S is a sample and is installed between the upper and lower rotary tables 11 and 12. Above the polarizer 1, 5 is a filter, which transmits light of a specific wavelength. 6
Is a halogen lamp as a light source, guided to the filter 5 through the optical fiber 7, and the filter-transmitted light is transmitted through the polarizer 1, the sample S, and the analyzer 2, and is detected by the light receiving element 8. The output of the light receiving element 8 is sent to the data processing device 10 through the amplifier 9. A pulse signal is emitted from the data processing device 10, is input to the motor drive circuit 13, is converted into a motor drive pulse, and is input to the motor 4. The data processor counts this pulse and detects the rotation angle of the polarizer and the analyzer. A quarter-wave plate 14 is rotatably inserted between the rotary table 11 and the sample S.
【０００９】１／４波長板１４はホルダ１５に装着さ
れ、ホルダ１５が保持台１６に回転可能になっている。
ホルダには角度目盛１５ａが一つ刻んであり、保持台１
６にはホルダの周囲に指標１６ａが刻んである。１／４
波長板１４は光学軸の一つの方向をホルダの角度目盛１
５ａの０°に合わせてホルダ１５に取り付ける。測定は
１５ａの０°位置を保持台の指標１６ａの０°の位置に
合わせて開始する。この説明では波長板１４として市販
の１／４波長板を用いているが、これは１／４波長に限
ることはなく、レターデーションが２πから離れている
ものであればよいので、適当な厚さのシートとか板でレ
ターデーションおよび光学軸の方向を図１の装置を用い
て測定して、それを用いてもよい。図１の装置目的はレ
ターデーションおよび光学軸の方向を決定する装置であ
るから、レターデーションが波長の整数倍の近くでない
試料についてはこれを用いてレターデーションおよび光
学軸の方向を正確に知ることができる。The quarter-wave plate 14 is mounted on a holder 15, and the holder 15 is rotatable on a holder 16.
The holder has one angle scale 15a, and the holder 1
An index 16a is engraved on the periphery of the holder 6 in FIG. 1/4
The wave plate 14 has one direction of the optical axis and the angle scale 1 of the holder.
It is attached to the holder 15 according to 0 ° of 5a. The measurement is started by aligning the 0 ° position of 15a with the 0 ° position of the index 16a of the holding table. In this description, a commercially available quarter-wave plate is used as the wave plate 14, but this is not limited to a quarter-wave plate, as long as the retardation is apart from 2π, a suitable thickness is used. It is also possible to measure the retardation and the direction of the optical axis using a sheet or a plate of a sword and to use it. Since the purpose of the apparatus in FIG. 1 is to determine the direction of the retardation and the optical axis, it is necessary to accurately know the direction of the retardation and the optical axis using a sample for which the retardation is not close to an integral multiple of the wavelength. You can
【００１０】上述の装置を用いて測定は次のようにして
行われる。まず１／４波長板１４のホルダの０°位置を
保持台の指標１６ａに合わせる。即ち波長板１４の光学
軸の方向をこの０°の方向にセットする。このようにし
て偏光子１，検光子２を回転させ、その角位置データと
受光素子８の出力データを取り込み、偏光子，検光子を
一回転させる。次に波長板のホルダ１５を角度１０°回
して上と同じように偏光子，検光子の角位置データと受
光素子出力のデータを取り込む。以後同様の動作を波長
板１４の向きを１０°ずつ変えながら、波長板１４の回
転角が１７０°になる迄繰り返す。図２Ａ，Ｂはこのよ
うにして得られた測定データから、波長板１４の向きが
或る二つの方向である場合についてのデータを記録した
もので、偏光子，検光子の回転角を極座標の角度座標に
とり、動径長さを受光素子出力とした極座標記録であ
り、十字花径の図形であるが、Ａは波長板１４と試料と
の合成レターデーションが大きい場合、Ｂは小さい場合
で、Ｂでは図形は略円になっている。The measurement is performed as follows using the above apparatus. First, the 0 ° position of the holder of the quarter-wave plate 14 is aligned with the index 16a of the holding table. That is, the direction of the optical axis of the wave plate 14 is set to this 0 ° direction. In this way, the polarizer 1 and the analyzer 2 are rotated, the angular position data and the output data of the light receiving element 8 are taken in, and the polarizer and the analyzer are rotated once. Next, the wavelength plate holder 15 is rotated by an angle of 10 °, and the angular position data of the polarizer and the analyzer and the data of the light receiving element output are taken in the same manner as above. Thereafter, the same operation is repeated while changing the direction of the wave plate 14 by 10 ° until the rotation angle of the wave plate 14 reaches 170 °. FIGS. 2A and 2B are data obtained by recording the thus obtained measurement data in the case where the wave plate 14 is oriented in two directions, and the rotation angles of the polarizer and the analyzer are expressed in polar coordinates. It is a polar coordinate record in which the radial length is the output of the light receiving element in angular coordinates, and it is a figure of a cross flower diameter. A is when the combined retardation of the wave plate 14 and the sample is large, and B is small, In B, the figure is almost a circle.
【００１１】上述した測定データから次のようにして試
料の光学軸の方位および試料のレターデーションを求め
る。波長板１４の或る角位置における受光素子８の出力
データの最大Ｉｏと最小Ｉｍｉｎとの差とＩｏとの比
は、レターデーションを位相差角で表わして２ｎπ＋δ
とすると、 （Ｉｏ−Ｉｍｉｎ）／Ｉｏ＝ｃｏｓ（２ｎπ＋δ）＝ｃ
ｏｓδ である。測定データから波長板１４の角位置０°，１０
°，…１７０°におけるｃｏｓδを算出する。その最小
値と前後２つのｃｏｓδの値を取出し、それらをｙ1 ，
ｙ2 ，ｙ3 とし、ｃｏｓδを最小に対する波長板の角位
置をφとして、このφを変数ｘの０点とし、それより１
０°前の位置を−１０，１０°後の位置を＋１０として ｙ＝ａ＋ｂｘ＋ｃｘ2 ……(1) に上記ｙ1 等とｘ＝−１０，０，１０を代入した３式 ｙ1 ＝ａ−１０ｂ＋１００ｃ ｙ2 ＝ａ ｙ3 ＝ａ＋１０ｂ＋１００ｃ からａ，ｂ，ｃを計算し、 ｄｙ／ｄｘ＝ｂ＋２ｃｘ＝０ に上に求めたｂ，ｃを代入してｘを求めると、レターデ
ーション最大に対する波長板１４の角位置はφ＋ｘとな
り、このときのｃｏｓδは前記(1) 式に上に求めたａ，
ｂ，ｃ，ｘを入れたときのｙの値で与えられる。このよ
うにしてδが求まると、それから波長板自身のレターデ
ーションの位相角を引き算して、試料のレターデーショ
ンの位相角が求まる。また試料の光学軸の一つの方向は
装置の保持台１６の指標方向を基準にしてφ＋ｘとなっ
ている。このようにして試料の光学軸の方向およびレタ
ーデーションが求まったら、試料と位相板の夫々の光学
軸を保持台１６の指標１６ａの方向に合わせ、試料をこ
の指標方向の軸を中心に傾け、傾角０から傾角を増しな
がら、レターデーションを測定し、傾角とこのレターデ
ーションの関係から試料の第３光学軸方向の屈折率を求
める。或は試料が単軸性複屈折を呈する材料である場
合、試料を傾けながらレターデーションを測定すること
で、レターデーションの次数即ち位相差角２ｎπ＋δの
ｎを決定することができる。From the above measurement data, the azimuth of the optical axis of the sample and the retardation of the sample are obtained as follows. The ratio of Io to the difference between the maximum Io and the minimum Imin of the output data of the light receiving element 8 at a certain angular position of the wave plate 14 is represented by a retardation of 2nπ + δ.
Then, (Io-Imin) / Io = cos (2nπ + δ) = c
osδ. From the measurement data, the angular position of the wave plate 14 is 0 °, 10
Cos δ at 170 ° is calculated. Take the minimum value and the two cos δ values before and after, and set them to y 1 ,
Let y 2 and y 3, and let φ be the angular position of the wave plate with respect to cos δ with respect to the minimum.
0 ° before y = a + bx + cx 2 position position after -10,10 ° as +10 to ... (1) to the y 1, etc. and x = -10,0,10 3 formula obtained by substituting y 1 = a- 10b + 100c y 2 = a y 3 = a + 10b + 100c is calculated from a, b, and c, and dy / dx = b + 2cx = 0 is substituted with b and c obtained above to obtain x. The angular position of is φ + x, and cos δ at this time is a, which is obtained in the above equation (1),
It is given by the value of y when b, c and x are entered. When δ is obtained in this way, the phase angle of the retardation of the wave plate itself is subtracted from that to obtain the phase angle of the retardation of the sample. Further, one direction of the optical axis of the sample is φ + x with reference to the index direction of the holding table 16 of the apparatus. When the direction and retardation of the optical axis of the sample are obtained in this manner, the optical axes of the sample and the phase plate are aligned with the direction of the index 16a of the holding table 16, and the sample is tilted about the axis of the index direction. The retardation is measured while increasing the tilt angle from 0, and the refractive index of the sample in the third optical axis direction is obtained from the relationship between the tilt angle and this retardation. Alternatively, when the sample is a material exhibiting uniaxial birefringence, the retardation order, that is, n of the phase difference angle 2nπ + δ can be determined by measuring the retardation while tilting the sample.
【００１２】上述実施例は波長板を手動的に１０°ずつ
回して測定を繰り返すものであるが、図３は波長板を連
続的に回しながら測定を行うものである。図１の各部と
対応する部分には同じ符号がつけてある。１７は波長板
１４のホルダを駆動するプーリでパルスモータ４の軸と
歯車１８によって連結され、偏光子１，検光子２が１回
転する間に波長板を１°だけ回転させるようになってい
る。偏光子等が１回転する間に受光素子８の出力は４周
期の変化をする。受光素子８の出力波形は正弦波形で、
その振幅は波長板１４によって変調され、図４に示すよ
うに波長板１４の一回転の間に２周期の変化をする。こ
の振幅の最大値が試料と波長板の光学軸が一致したとき
の合成レターデーションの位相差各δのｃｏｓを与え
る。１９はピーク保持回路でダイオードｄとコンデンサ
ｃと放電用トランジスタＴとよりなっており、放電用ト
ランジスタＴは偏光子等の回転と同期して導通パルスが
印加されピーク保持回路１９をリセットする。図５はピ
ーク保持回路の動作のタイムチャートで、増幅器９の出
力（受光素子８の出力を反転したもの）のピークが保持
されている間にデータ処理装置１０はＡ／Ｄ変換器２０
を介して、そのピーク値のデータを取り込み、前の一周
期の間に取り込んだピーク値との差を算出する。データ
処理装置はこの差の符号が変化したときのピーク値およ
び、その前と更に前の前の２つのピーク値から、前記第
１２段落で説明した計算方法で、波長板の方向および最
大のレターデーションを算出する。この実施例では波長
板の１°の回転の間に偏光子等は１０回転し受光素子８
の出力は４０サイクルの変化をしているから、このよう
な補間計算をしなくても、差の符号が変わったときのピ
ーク値だけからレターデーションおよび波長板の方位を
決めても精度上は充分である。In the above-described embodiment, the wave plate is manually rotated by 10 ° and the measurement is repeated. In FIG. 3, the wave plate is continuously rotated to perform the measurement. Portions corresponding to those in FIG. 1 are designated by the same reference numerals. Reference numeral 17 is a pulley for driving the holder of the wave plate 14, which is connected to the shaft of the pulse motor 4 by the gear 18 and rotates the wave plate by 1 ° while the polarizer 1 and the analyzer 2 make one rotation. . The output of the light receiving element 8 changes for four cycles during one rotation of the polarizer or the like. The output waveform of the light receiving element 8 is a sine waveform,
The amplitude is modulated by the wave plate 14, and changes by two cycles during one rotation of the wave plate 14 as shown in FIG. The maximum value of this amplitude gives the cos of each phase difference δ of the synthetic retardation when the optical axis of the sample and that of the wave plate coincide. A peak holding circuit 19 is composed of a diode d, a capacitor c, and a discharging transistor T. The discharging transistor T resets the peak holding circuit 19 by applying a conduction pulse in synchronization with the rotation of the polarizer or the like. FIG. 5 is a time chart of the operation of the peak holding circuit. While the peak of the output of the amplifier 9 (inversion of the output of the light receiving element 8) is held, the data processing device 10 sets the A / D converter 20.
The peak value data is fetched via the, and the difference from the peak value fetched in the previous one cycle is calculated. Based on the peak value when the sign of the difference changes and the two peak values before and before the difference, the data processing device uses the calculation method described in the twelfth paragraph to determine the direction of the wave plate and the maximum letter. Calculate the foundation. In this embodiment, the polarizer or the like rotates 10 times during the rotation of the wave plate by 1 °, and the light receiving element 8
Output changes for 40 cycles, it is possible to determine the retardation and the azimuth of the wave plate only from the peak value when the sign of the difference is changed, without the need for such an interpolation calculation. Is enough.
【００１３】第１２段落で述べた試料を傾けて試料の３
軸方向の屈折率を求める方法は特願平４−１３１８６１
（平成４年４月２４日出願）に記載されている。試料を
傾けてレターデーションの次数を決めるには次のように
する。試料の傾に対するレターデーションの変化は次数
が増す程大きくなる。即ちレターデーションの傾角敏感
性は次数が大きくなる程大きくなる。このことを利用し
て、予め試料の傾角０とαの両方の間のレターデーショ
ンの変化率と次数との関係を実験的に求めておき試料に
ついて、上記変化率を測定することで次数を決めること
ができる。これはもちろん計算によっても決めることが
できる。即ち次数ｎ＝０のとき、試料をαだけ傾けてレ
ターデーションがΔだけ変化したとすると、次数ｎのと
きは（ｎ＋１）Δだけ変化するｏｎ＝０のとき、試料を
α傾けることは試料の厚さをもとの１／ｃｏｓα倍した
のと同じで、位相差角δも１／ｃｏｓα倍になる。αは
小さい角度であるから、１／ｃｏｓα＝１＋α2 ／２と
して、傾角０°のときの位相差角をδとすると、αだけ
傾けたときの変化率はδα／２、次数がｎのときは（ｎ
＋１）δα2 ／２、従って実測された位相差角の変化Δ
をδα2 ／２で割り算すればｎが求まる。The sample described in the 12th paragraph is tilted and
A method for obtaining the refractive index in the axial direction is described in Japanese Patent Application No. 4-131861.
(Filed April 24, 1992). Tilt the sample to determine the order of retardation as follows. The change in retardation with respect to the inclination of the sample increases as the order increases. That is, the inclination sensitivity of retardation increases as the order increases. Utilizing this fact, the relationship between the rate of change in retardation between both the tilt angles 0 and α of the sample and the order is experimentally obtained in advance, and the order is determined by measuring the rate of change of the sample. be able to. This can of course be determined by calculation. That is, when the sample is tilted by α and the retardation is changed by Δ when the order is n = 0, it is changed by (n + 1) Δ when the order is n. The same as multiplying the thickness by 1 / cos α, the phase difference angle δ also becomes 1 / cos α. Since alpha is a small angle, 1 / as cosα = 1 + α 2/2 , when the phase difference angle when the inclination angle 0 ° and [delta], the change rate when tilted alpha when .delta..alpha / 2, the order is n Is (n
+1) δα 2/2, therefore the change of the measured phase difference angle Δ
A n is obtained if divided by δα 2/2.
【００１４】[0014]
【発明の効果】本発明によれば波長板を重ねてレターデ
ーションを測定する場合、試料の光学軸の方向が予め不
明でも、光学軸の方向が精密に求められ、光学軸を装置
に対して所定の方向にセットして行う各種の測定が容易
になり、精度が向上する。According to the present invention, when the retardation is measured by stacking wave plates, even if the direction of the optical axis of the sample is unknown in advance, the direction of the optical axis can be accurately determined, and the optical axis can be measured with respect to the device. Various kinds of measurement performed by setting in a predetermined direction are facilitated and accuracy is improved.
【図１】本発明方法を実施する装置の一例の斜視図FIG. 1 is a perspective view of an example of an apparatus for carrying out the method of the present invention.
【図２】上述実施例で得られる測定記録のグラフFIG. 2 is a graph of measurement records obtained in the above-mentioned embodiment.
【図３】本発明方法を実施する装置の他の例の斜視図FIG. 3 is a perspective view of another example of the apparatus for carrying out the method of the present invention.
【図４】受光素子８および増幅器９の出力のグラフFIG. 4 is a graph of outputs of a light receiving element 8 and an amplifier 9.
【図５】上記装置のピーク保持回路の動作のタイムチャ
ートFIG. 5 is a time chart of the operation of the peak hold circuit of the above device.
１ 偏光子 ２ 検光子 ４ パルスモータ ５ フィルタ ６ 光源 ８ 受光素子 ９ 増幅器 １０ データ処理装置 １４ 波長板 １５ 波長板ホルダ １６ 保持台 １７ プーリ １８ 歯車 １９ ピーク保持回路 ２０ Ａ／Ｄ変換器 1 Polarizer 2 Analyzer 4 Pulse motor 5 Filter 6 Light source 8 Light receiving element 9 Amplifier 10 Data processing device 14 Wave plate 15 Wave plate holder 16 Holding stand 17 Pulley 18 Gear 19 Peak holding circuit 20 A / D converter
Claims (1)
位が既知の波長板を重ね、試料に対して波長板を回転さ
せながら、両者の合成レターデーションを測定し、レタ
ーデーションが最大になるときの波長板の方向およびそ
のときの試料，波長板の合成レターデーションを求める
ことを特徴とするレターデーション測定方法。1. A sample is overlaid with a wave plate having a known retardation and azimuth of an optical axis, and while the wave plate is rotated with respect to the sample, a combined retardation of both is measured, and when the retardation becomes maximum. A retardation measuring method characterized by obtaining the direction of the wave plate, the sample at that time, and the synthetic retardation of the wave plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP36056792A JPH06229910A (en) | 1992-12-29 | 1992-12-29 | Measuring method for retardation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP36056792A JPH06229910A (en) | 1992-12-29 | 1992-12-29 | Measuring method for retardation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06229910A true JPH06229910A (en) | 1994-08-19 |
Family
ID=18469964
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP36056792A Pending JPH06229910A (en) | 1992-12-29 | 1992-12-29 | Measuring method for retardation |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06229910A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007139722A (en) * | 2005-11-22 | 2007-06-07 | Tokyo Univ Of Agriculture & Technology | Instrument and method for measuring optical characteristic |
| JP2009122152A (en) * | 2007-11-12 | 2009-06-04 | Oji Keisoku Kiki Kk | Method of analyzing polarization |
| JP2011017875A (en) * | 2009-07-08 | 2011-01-27 | Olympus Corp | Observation device |
-
1992
- 1992-12-29 JP JP36056792A patent/JPH06229910A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007139722A (en) * | 2005-11-22 | 2007-06-07 | Tokyo Univ Of Agriculture & Technology | Instrument and method for measuring optical characteristic |
| JP2009122152A (en) * | 2007-11-12 | 2009-06-04 | Oji Keisoku Kiki Kk | Method of analyzing polarization |
| JP2011017875A (en) * | 2009-07-08 | 2011-01-27 | Olympus Corp | Observation device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5504581A (en) | Method and apparatus for measuring birefringence | |
| JPH0478137B2 (en) | ||
| US6473181B1 (en) | Measurement of waveplate retardation using a photoelastic modulator | |
| US4850710A (en) | Method of measuring and displaying double refraction occurring in a material to be measured | |
| US4456339A (en) | Laser heterodyne surface profiler | |
| JPH06229910A (en) | Measuring method for retardation | |
| CN114720095A (en) | Device and method for measuring phase retardation and fast axis direction of wave plate | |
| JPH0283428A (en) | Automatic double refraction measuring apparatus | |
| JP2791479B2 (en) | Retardation measurement method | |
| JP2789575B2 (en) | Birefringence measurement device | |
| JP4926003B2 (en) | Polarization analysis method | |
| JPH06241987A (en) | Birefringence measuring device | |
| JP3539006B2 (en) | Method and apparatus for measuring retardation of composite layer | |
| JP2924938B2 (en) | Method for measuring retardation of composite film | |
| JPH06100535B2 (en) | Birefringence measuring device | |
| JP2712987B2 (en) | Adjustment method of polarization measuring device | |
| Oakberg | Measurement of low-level strain retardation in optical materials | |
| O'Flaherty et al. | System for high-sensitivity measurement of birefringence using a photoelastic modulator, and its applications | |
| JPH07301597A (en) | Apparatus for measuring retardation in polarization of sample | |
| JP2005283552A (en) | Birefringence measurement device and birefringence measurement method | |
| JP3554374B2 (en) | Polarimeter | |
| JPH06288899A (en) | Measuring method of polarization transmissivity characteristic of film | |
| JPH0552657A (en) | Polarization measurement equipment | |
| JPH01182737A (en) | Double-refraction measurement | |
| JP3136569B2 (en) | Method for measuring retardation of birefringent material |