JP2012173409A - Optical characteristic evaluation method and optical element inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical characteristic evaluation method capable of separating and evaluating a polarization characteristic in each minute region, and of grasping and evaluating an optical characteristic that cannot be obtained through a conventional technology.SOLUTION: An optical characteristic evaluation method includes: a step for arranging a polarizer 20 for converting an unpolarized light to a linearly-polarized light, a polarization element 10 having two mutually-perpendicular transmission axes, an analyzer 30 for transmitting a characteristic component of light emitted from the polarization element 10 and a detector 2 for detecting intensity of light emitted from the analyzer 30, on an optical path; a step for measuring a transmittance based on the intensity of the light emitted from the analyzer 30 by signal processing means 3 that is connected to the detector 2, by fixing the analyzer 30 at an angle of 45° with respect to each transmission axis and emitting light from a light source 1 while rotating the polarizer 20; and a step for calculating a transmittance of the polarization element 10 based on the measured transmittance.

Description

  The present invention relates to a method for evaluating optical characteristics of a flat plate-type optical element such as a wire grid polarizer and a method for inspecting an optical element based on the evaluated optical characteristics.

With the progress of recent microfabrication technology, it is possible to form a fine structure pattern having a light wavelength level pitch. In the optical field, in particular, development of a flat plate type optical element using the fine structure pattern is progressing. .
An example of a flat plate-type optical element is a polarizer. Such a polarizer is used not only as a polarizing beam splitter or an analyzer in a projector, but also as a reflective polarizer for polarization reuse. (Non-Patent Document 1).
Furthermore, as an example of a flat plate type polarizer, there is a wire grid type polarizer composed of parallel conductive wire arrays as shown in Non-Patent Document 2.
Radio wave polarization formation using parallel conductive wire arrays and infrared polarizers in the electromagnetic spectrum have been known for a long time, but the grid spacing can be reduced to 100 nm or less with the advancement of the aforementioned microfabrication technology. Accordingly, a projector using a wire grid polarizer actually made of a metal nanostructure has been developed (Patent Document 1, Non-Patent Document 3).

FIG. 7 is a diagram for explaining the principle of the wire grid polarizer.
Moreover, FIG. 8 is a figure explaining the structure of the wire grid polarizer used conventionally, and the evaluation method of the optical characteristic.
As shown in FIGS. 7 and 8, optical characteristics such as light transmittance and extinction rate are detected and evaluated by actually applying spot light to the wire grid polarizer.
Here, the transmittance is defined as [(light intensity with sample) − (dark light intensity)] / [(light intensity without sample) − (dark light intensity)].
The definition of the extinction ratio (contrast) is (TM wave transmittance) / (TE wave transmittance).

In FIG. 7, the wire grid has a configuration in which a large number of fine metal wires (wires) 51 made of a conductor such as gold, silver, aluminum, or copper are stretched in parallel in the frame 50.
In an electromagnetic wave incident on the wire grid, a polarized wave having a plane of polarization parallel to the wire 51 (TE wave: Transverse Electric Wave, in the case of light, S-polarized light) is reflected and polarized with a plane of polarization perpendicular to the wire. By transmitting (TM wave: Transverse Magnetic Wave, P-polarized light in the case of light), it functions as a polarizing filter (polarizer) that extracts only TM polarized light from non-polarized light (random polarized light).
However, in order for the wire grid to function as a polarizing filter, it is a condition that the interval or period of the fine metal wires is smaller than the wavelength of the electromagnetic wave (light).
In the equation shown in FIG. 7, T _p is the transmittance of the TE wave, T _v is the transmittance of the TM wave, and from each metal thin wire 51 (cylindrical perfect conductor, radius a, lattice constant d). It is the intensity | strength transmittance calculated | required by adding a scattered wave (wavelength (lambda)).
As shown in FIG. 7, the measurement spot light irradiation side surface (incident surface) in the wire grid element has a transmittance of transmitted TM waves to the main body side surface (outgoing surface) of 1 (all TM waves are transmitted and transmitted). Ideally, the transmittance of the TE wave reflected on the spot light irradiation side is zero (the TE wave is totally reflected, that is, the TE wave is not emitted). Is.

By the way, the wire grid polarizer has been mainly used as a polarizer having a wire grid in only one direction and having the transmission axis of the polarizer formed in only one direction. Along with this, it is possible to form a device in which wire grids in a plurality of directions are formed and different transmission axis directions are mixed, and a technique for using the optical characteristics and projection images as information is advancing.
Particularly in recent years, not only a line pattern (vertical wire grid 60) in only one direction as shown in FIG. 8 (a) but also a line pattern region (vertical direction) in two orthogonal directions as shown in FIG. 8 (b). The technology used by separating the linearly polarized light orthogonal to each other by a polarizing filter in which the directional wire grid 60 and the horizontal wire grid 61) are mixed in the same plane is used for cameras and projectors that require high image quality (high resolution). It has been sought in the field.

However, although there is such a demand as described above, a conventional wire grid element evaluation method for measuring transmittance and reflectance using probe light at the measurement spot 62 in FIG. 8 is as shown in FIG. For region dividing elements having a pattern in which line patterns of two orthogonal wire grids are mixed in the same plane, the optical characteristics of transmittance and reflectance (specifically, TM as the transmittance on the transmission side) The transmittance and TE transmittance as the cutoff side transmittance) could not be derived as numerical values, and there was a problem that an actually fabricated device could not be inspected.
Specifically, in the case shown in FIG. 8A, the pattern region (longitudinal wire grid 60) is sufficiently larger than the measurement spot 62 (wire grid 60> measurement spot 62), and optical characteristics such as transmittance can be measured. Although it is possible, in the case of FIG. 8 (b), the measurement spot 62 is usually several mm, whereas each divided pattern region (vertical wire grid 60, horizontal wire grid 61) is several μm in width. Since the light is emitted from the exit surface side of the measurement spot 62 (each of the polarized light components), it is much smaller than this (measurement spot 62> wire grids 60, 61). It is almost impossible to directly derive the characteristics of each pattern region.
Even if a monitor pattern with a wide wire grid area is provided in the vicinity, the width of the monitor pattern and the pattern width of the vertical and horizontal lines at the divided areas are often different, and the monitor pattern and the mixed pattern (FIG. 8B) Since the characteristics do not match, it is still impossible to accurately evaluate the characteristics, and it is necessary to directly evaluate the area division pattern in a non-destructive manner.

For the purpose of producing a unidirectional polarizer, the above-mentioned Patent Document 1 discloses a structure with good optical characteristics and a method for producing the same. Since there has been no means or device for detecting characteristics using light, no technique for solving the above-described problems has been disclosed.
Therefore, the present invention applies the formula for calculating the transmittance of a polarizer such as a wire grid element having a normal one-light pattern shown in FIG. To provide an optical property evaluation method that can evaluate and evaluate polarization characteristics in each region separately for different patterns, grasp optical properties that could not be obtained by conventional techniques, and evaluate them. Objective. That is, an object is to make it possible to determine the difference between the TE transmittance and TM transmittance of the measurement object and the optical characteristics in the vertical and horizontal directions.

  In order to solve the above problems, the invention of claim 1 has a first transmission axis and a second transmission axis orthogonal to each other, and each transmission axis distributed within the diameter of the light emitted from the light source. An optical property evaluation method for measuring light transmittance in a polarizing element that transmits one of an orthogonal polarization component and a parallel polarization component, the polarizer converting non-polarized light into linearly polarized light, and the polarization An element, an analyzer that transmits a specific component of light emitted from the polarizing element, and a detector that detects the intensity of light emitted from the analyzer are arranged on an optical path, and the angle of the analyzer Is fixed at 45 ° with respect to each transmission axis, light is emitted from the light source while rotating the polarizer, and the intensity of light emitted from the analyzer is detected by the detector, and the detection is performed. Output from the analyzer by signal processing means connected to the detector. It is the characterized optical properties evaluation method for calculating a transmittance of light in the polarizing element on the basis of the intensity of light.

  Further, the invention of claim 2 has a first transmission axis and a second transmission axis orthogonal to each other, and the polarization component orthogonal to each transmission axis distributed within the diameter of light emitted from the light source and parallel to each other. An optical property evaluation method for measuring light transmittance in a polarizing element that transmits any one of polarization components, a polarizer that converts non-polarized light into linearly polarized light, the polarizing element, and the output from the polarizing element An analyzer that transmits a specific component of the light to be transmitted and a detector that detects the intensity of light emitted from the analyzer are disposed on the optical path, and the angle of the analyzer is set on the first transmission axis. The intensity of light transmitted from the first transmission axis that is emitted from the light source by the detector while rotating the polarizer and is emitted from the analyzer by the detector is detected by fixing the same direction. Then, the signal processing means performs the first transmission based on the intensity. The light transmittance at the axis is calculated, the angle of the analyzer is fixed to be the same as the direction of the second transmission axis, the light is emitted from the light source while rotating the polarizer, and the detector Optical characteristic evaluation for detecting the intensity of light emitted from the analyzer and transmitted from the second transmission axis, and calculating the light transmittance at the second transmission axis based on the intensity by the signal processing means Features method.

  The invention of claim 3 is characterized by a method for inspecting an optical element that detects a variation in the optical characteristic in the plane of the polarizing element from the optical characteristic obtained by the optical characteristic evaluation method according to claim 1 or 2. And

  Since it was configured as described above, according to the present invention, the TE transmittance and TM transmittance of the entire sample can be obtained even for a sample (wire grid polarizer) having different polarization characteristics for each minute region (wire grid region). It is possible to digitize optical characteristics and grasp optical characteristics that could not be obtained conventionally.

The figure which shows the concept of the optical system which guide | induces the transmittance | permeability at the time of fixing an analyzer angle to x-axis, and the Jones vector of each element. The figure which shows the concept of the optical system which guide | induces the transmittance | permeability at the time of fixing an analyzer angle to x-axis, and the Jones vector of each element. The graph which shows the transmittance | permeability at the time of making the angle of an analyzer into 0 degree (it shall be a vertical direction) and changing the angle of a polarizer. The graph which shows the transmittance | permeability at the time of making the angle of an analyzer into 90 degrees (it shall be a horizontal direction) and changing a polarizer angle. The graph which shows the transmittance | permeability at the time of making the angle of an analyzer into 45 degrees (vertical direction, 45 degrees from a horizontal direction), and changing a polarizer angle. The figure which shows the example of the relationship between the wire grid as a measuring object in this invention, and a measurement spot diameter. The figure explaining the principle of a wire grid polarizer. The figure explaining the evaluation method of the optical characteristic of the wire grid polarizer used conventionally.

Embodiments of the present invention will be described below in detail with reference to the drawings.
Further, since the configuration of the wire grid polarizer itself is the same as the conventional one, FIG. 8B is also referred to as a polarizer applicable to the present application.
As described above, it is an optical characteristic of a wire grid polarizer that cannot be measured when the wire direction (transmission axis direction) is mixed in the same plane, but the wire direction is random. Instead, when the two directions are orthogonal, the optical characteristics can be measured by devising the measurement method.
In the present invention, the optical characteristics of the elements (x-direction (lateral direction) wire grid 61 region and y-direction (vertical direction) wire grid 60 region) having wire grids in the xy2 directions perpendicular to each other are determined by the following two methods. Evaluate by grasping the transmittance.
In addition, the measurement of the optical characteristics of the wire grid polarizer described below is performed by converting the non-polarized light emitted from the light source 1 and the light source 1 that emits the spot light shown in FIGS. 1 and 2 to linearly polarized light. A polarizer (1/2 retardation plate) 20, a sample stage (not shown) on which a wire grid element 10 as a sample is installed, a specific component of light transmitted through the orthogonal wire grid region and emitted from the polarizer 10 is transmitted. An analyzer 30 which is another polarizer to be made, a detector (detector) 2 for detecting the intensity of light emitted from the analyzer 30, and a signal processing unit 3 for calculating optical characteristics such as transmittance from the electric field vector of the emitted light. Use the system provided.

[Example 1]
First, the first method will be described.
Method (1): The analyzer 30 is fixed on the x-axis (the direction of the longitudinal wire grid 60) (x component: TM wave transmitted from the x-axis is transmitted), and the polarizer 20 is the optical axis of the emitted light from the light source. Rotate around 1a (φdeg).
In the case of the method (1), it is possible to obtain the average transmittance of the TE wave transmittance and the TM wave transmittance of one-side components of the two-dimensional pattern (vertical wire grid 60, horizontal wire grid 61). This is because TM waves transmitted from the wire grid 60 and the wire grid 61 and TM waves having mutually orthogonal planes of polarization are mixed in the transmitted TM wave emitted from the wire grid polarizer 30. This is because only the TM wave transmitted from the longitudinal wire grid 60 passes through (in fact, the optical axis is at an angle of 45 ° with respect to the x-axis).
In addition, since the intensity is transmitted TM wave >> transmitted TE wave, an approximate TM component is known.

…式（１）
したがって、検光子３０を透過した光の電場ベクトルは次式（２）で与えられる。ただし、ｘ方向ワイヤグリッド領域と、ｙ方向ワイヤグリッド領域を透過した光の干渉項は無視した。

…式（２）
上式より、ｔ^２ _ＴＭ＋ｔ^２ _ＴＥ〜ｔ^２ _ＴＭ（ｔ_ＴＭ＞＞ｔ_ＴＥ）とすれば、ｃｏｓ成分の振幅の大きさ（もしくは振動中心）がワイヤグリッド偏光子２０の透過側成分の透過率（ｔ^２ _ＴＭ）に一致する。 FIG. 1 is a diagram showing the concept of an optical system for deriving transmittance and the Jones vector of each element in the case of the method (1), that is, when the analyzer angle is fixed to the x-axis.
The transmittance is calculated by a signal processing device (signal processing means) such as a PC (Personal Computer) connected to the detector 2.
Here, it is assumed that the transmission coefficients of the x-direction wire grid region 61 and the y-direction wire grid region 60 are uniform.
The electric field vector of the light that has passed through the analyzer 30 and entered the detector 2 is given by the following equation (1).

... Formula (1)
Therefore, the electric field vector of the light transmitted through the analyzer 30 is given by the following equation (2). However, the interference term of the light transmitted through the x-direction wire grid region and the y-direction wire grid region was ignored.

... Formula (2)
From the above ^equation, if _{^{t 2 TM + t 2 TE ~t}} 2 TM (t TM >> t TE), the magnitude of the amplitude of the cos component (or vibration center) the transmission of the transmission side components of the wire grid polarizer 20 It corresponds to the rate (t ² _TM ).

Next, the second method will be described.
Method (2): The analyzer 30 is fixed at 45 ° with respect to the x-axis and y-axis (45 ° component transmission (actually, the angle of the optical axis with respect to the x-axis is 90 °)), and the polarizer 20 Rotate around axis 1a (φdeg)
In the case of the method (2), the direct current component and the vibration component are obtained, and the transmittance of the TE wave and the TM wave, that is, the transmittance and the extinction ratio can be calculated from the respective sizes.

…式（３）
検光子３０を透過した光の電場ベクトルは次式（４）で与えられる。ただし、ｘ方向ワイヤグリッド領域６１と、ｙ方向ワイヤグリッド領域６２を透過した光の干渉項は無視した。

…式（４）
上式（３）、（４）より、偏光子角度に対する振動成分と直流成分を抽出すれば、ｔ_ＴＭ、ｔ_ＴＥの連立方程式から各成分が算出できる。連立方程式の解を用いて透過率および消光比を導出すると、以下のように求められる。

さらに、検光子３０の角度を９０°（実際は、光学軸のｘ軸に対する角度が１３５°）に固定して、同様に偏光子２０を回転させて透過率を測定する。
つまり、直交する二方向のワイヤグリッドであっても、検光子３０の角度を特定の角度（０°、４５°、９０°）とし、偏光子２０を回転させて透過率を測定することにより、ＴＭ透過率、ＴＥ透過率、おおよその消光比などの値を得られる。 FIG. 2 is a diagram showing the concept of the optical system for guiding the transmittance in the case of method (2), that is, when the analyzer angle is fixed at 45 °, and the Jones vector of each element.
The electric field vector of the light transmitted through the analyzer 30 is given by the following equation (3).

... Formula (3)
The electric field vector of the light transmitted through the analyzer 30 is given by the following equation (4). However, the interference term of the light transmitted through the x-direction wire grid region 61 and the y-direction wire grid region 62 was ignored.

... Formula (4)
If the vibration component and the direct current component with respect to the polarizer angle are extracted from the above equations (3) and (4), each component can be calculated from the simultaneous equations of t _TM and t _TE . When the transmittance and the extinction ratio are derived using the solution of the simultaneous equations, they are obtained as follows.

Further, the transmittance of the analyzer 30 is measured by fixing the angle of the analyzer 30 to 90 ° (actually, the angle of the optical axis with respect to the x-axis is 135 °) and rotating the polarizer 20 in the same manner.
In other words, even in the case of two orthogonal wire grids, the angle of the analyzer 30 is set to a specific angle (0 °, 45 °, 90 °), and the transmittance is measured by rotating the polarizer 20. Values such as TM transmittance, TE transmittance, and approximate extinction ratio can be obtained.

An example of the measurement result of transmittance is shown below. The object to be measured is a wire grid element having two orthogonal directions (vertical and horizontal). Note that the light wavelength is 550 nm.
In the following description, a case where the vertical direction (y-axis) is 0 ° in the xy coordinate axis will be described.
FIG. 3 is a graph showing the change in transmittance when the angle of the analyzer 30 is 0 ° (vertical direction) and the angle of the polarizer 20 is changed.
In FIG. 3, since the angle of the analyzer 30 is 0 ° (only the polarized light transmitted from the vertical wire grid 60 is transmitted), the polarized light in the vertical direction is transmitted when the angle of the polarizer 20 is also 0 °.
Therefore, it can be said that the transmittance when the angles of the analyzer 30 and the polarizer 20 are both 0 ° indicates the transmission function (characteristic) of the wire grid region 60 in the vertical direction in the measurement sample 10.

FIG. 4 is a graph showing the transmittance when the angle of the analyzer is 90 ° (lateral direction) and the polarizer angle is changed.
In FIG. 4, since the angle of the analyzer 30 is 90 ° (only the polarized light transmitted from the horizontal wire grid 61 is transmitted), the polarized light in the horizontal direction is transmitted when the angle of the polarizer 20 is also 90 °. Therefore, it can be said that the transmittance when the analyzer 30 and the polarizer 20 are both 90 ° indicates the transmission function (characteristic) of the horizontal wire grid in the measurement sample 10.

FIG. 5 is a graph showing the transmittance when the angle of the analyzer is 45 ° (vertical direction, 45 ° from the horizontal direction) and the polarizer angle is changed.
FIG. 5 shows the dependence of the transmittance on the polarizer angle when the angle of the analyzer 30 is 45 °. Therefore, the TM transmittance of the entire wire grid element 10 as a sample is calculated by the calculation shown in FIG. , TE transmittance can be calculated.
Thus, it is possible to calculate the TM transmittance and the TE transmittance of the entire wire grid element 10 only from the measured value of the analyzer 45 °.
When an approximate expression was found in the measurement results and converted from the values, the TM transmittance was found to be 83% and the TE transmittance was found to be 2.5%.
This value is calculated based on the assumption that the transmittance in the vertical direction and the horizontal direction is the same for the entire sample, but the TM transmittance and the TE transmittance in only the vertical direction and only in the horizontal direction are calculated by more rigorous calculation. It is also possible to ask for it.
Therefore, as a measurement procedure, first, the transmittance is measured by rotating the polarizer with the analyzer angle set to 0 °, and then the same measurement is performed at 45 ° and 90 °.
By combining the transmittance measuring device with a mechanism for calculating the transmittance value, the optical characteristics of the sample can be immediately grasped.
Here, the procedure for acquiring the transmittance with the angle of the analyzer 30 being 0 °, 45 °, and 90 ° may be from any angle.

Further, as described above, in principle, the TM transmittance and the TE transmittance can be calculated only by the transmittance result obtained by rotating the polarizer with the analyzer angle set to 45 °.
Moreover, although the value of wavelength 550nm was taken out in the Example, when a halogen light source is used, the wavelength dependence of these characteristics can be calculated | required.
Further, it is possible to determine the difference in optical characteristics between two orthogonal directions (vertical direction and horizontal direction), to inspect the finally manufactured element, and to determine the performance as an optical element.
As a precaution for measurement, as shown in FIG. 8B, the laser light from the light source covers almost the same area (same ratio) in the two areas of the wire grid (the x-direction wire grid area and the y-direction wire grid area). It is necessary to irradiate with. Therefore, it is necessary that the two-direction areas exist in the measurement spot at the same rate.
When laser light is used, it is necessary to use a homogenizer or the like to widen the beam so as to have a uniform intensity.

FIG. 6 is a diagram illustrating an example of a relationship between a wire grid as a measurement target and a measurement spot diameter in the present invention.
In FIG. 6A, the vertical and horizontal wire grids 11 and 12 are alternately present in the same area.
FIG. 6B shows a case where the two-direction (longitudinal and lateral directions) wire grids 11 and 12 are alternately continuous in a parallelogram with the same area.
In any case, when the diameter of the measurement spot 13 is sufficiently large with respect to one side of the pattern area, the vertical and horizontal wire grid elements are included in the same area within the spot diameter.
A supplementary description is given of a method of collecting and measuring light having a strong directivity such as a laser.
When the width of each region (x direction (horizontal direction) wire grid region 11 and y direction (vertical direction) wire grid region 12) is several micrometers, it cannot be measured with laser light.
On the other hand, when it has a size of 10 μm or more, it is possible to obtain the transmittance for each region by condensing the laser beam with an objective lens or the like, and the measurement method as in this content is not necessary.
Therefore, this method is effective for a sample having a size that is difficult to measure even when the laser is focused, specifically, a measurement sample in which regions of several μm or less exist alternately.

[Example 2]
For the same wire grid element as in Example 1, in addition to the transmittance when the analyzer 30 is 45 °, the transmittance when the analyzer 30 is 0 ° and 90 ° is measured, and the TM transmittance, TE transmittance was calculated.
For example, when a sample is picked up, the TM transmittance is 85.0% and the TE transmittance is 0.4% with respect to the vertical wire grid line, and the TM transmittance is 0.4% with respect to the horizontal wire grid line. The transmittance was 86.5% and the TE transmittance was 0.5%.
When the measured values when the analyzer is 0 ° and 90 ° are also measured, more calculated values are used, so that the accuracy of calculating the TM transmittance and the TE transmittance can be improved. .

[Example 3]
In this example, in-plane optical measurement was performed. A wafer was prepared in which 8 × 8 elements similar to those in Example 1 were arranged at regular intervals in a 4-inch wafer.
A mechanism capable of automatically feeding the wafer was added to the sample stage, and the wafer was transported to the optical property measurement position.
The direction of the polarizer was grasped by a camera image, and the direction was aligned. Thereafter, TM transmittance and TE transmittance were measured for each element. By setting the values set as specifications for the measurement results (for example, TM transmittance of 85.0% or more and TE transmittance of 0.8% or less in each of the vertical and horizontal directions) as a good / bad boundary, It was confirmed that it was possible to distinguish between defective products and defective products. The data of each element was processed by a computer, and as a result, it was confirmed what optical characteristic distribution the wafer surface having 8 × 8 elements had.
It was confirmed that it can also be used as an inspection device by providing an automatic movement mechanism for the measurement position in the wafer and a measurement value discrimination mechanism.
Even on a wafer in which a large number of polarizers having a two-dimensional pattern are arranged, the optical characteristics including the polarization transmittance can be acquired and used as an inspection process for checking whether the optical characteristics are a predetermined value.

DESCRIPTION OF SYMBOLS 1 Light source, 2 Detector, 3 Signal processing part, 10 Wire grid element, 20 Polarizer, 30 Analyzer, 50 frames, 60 Horizontal wire grid, 61 Vertical wire grid, 62 Measurement spot

Special Table 2003-502708

‘Simulation of sub-100nm gratings incorporated in LCD stack’, M. Paukshto, K. Lovetsky, A. Zhukov, V. Smirnov, D. Kibalov, and G. King ’, SID 06 DIGEST, 848 (2006). “3rd Pencil of Light”, Tatsuo Tatsuo, p. 278, New Technology Communications '30 -nm-wide aluminum nanowire grid for ultrahigh contrast and transmittance polarizers made by UV-nanoimprint lithography ', JJ Wang, L. Chen, X. Liu, P. Sciortino, F. Liu, F. Walters, and X. Deng , Appl.Phys.Lett. 89, 141105 (2006).

Claims (3)

It has a first transmission axis and a second transmission axis that are orthogonal to each other, and transmits either one of the polarization component orthogonal to each transmission axis distributed within the diameter of the light emitted from the light source or the parallel polarization component. An optical property evaluation method for measuring light transmittance in a polarizing element,
A polarizer that converts non-polarized light into linearly polarized light, the polarizing element, an analyzer that transmits a specific component of the light emitted from the polarizing element, and a detection that detects the intensity of the light emitted from the analyzer Placed on the optical path,
The angle of the analyzer is fixed at 45 ° with respect to each transmission axis, the light is emitted from the light source while rotating the polarizer, and the intensity of the light emitted from the analyzer by the detector is adjusted. Detect
A method for evaluating optical characteristics, comprising: calculating light transmittance of the polarizing element based on intensity of light emitted from the analyzer by signal processing means connected to the detector. It has a first transmission axis and a second transmission axis that are orthogonal to each other, and transmits either one of the polarization component orthogonal to each transmission axis distributed within the diameter of the light emitted from the light source or the parallel polarization component. An optical property evaluation method for measuring light transmittance in a polarizing element,
A polarizer that converts non-polarized light into linearly polarized light, the polarizing element, an analyzer that transmits a specific component of the light emitted from the polarizing element, and a detection that detects the intensity of the light emitted from the analyzer Placed on the optical path,
The angle of the analyzer is fixed to be the same as the direction of the first transmission axis, the light is emitted from the light source while rotating the polarizer, and the detector emits the light from the analyzer. Detect the intensity of light transmitted from the transmission axis of 1,
The signal processing means calculates the light transmittance in the first transmission axis based on the intensity,
The angle of the analyzer is fixed to be the same as the direction of the second transmission axis, the light is emitted from the light source while rotating the polarizer, and the detector emits the light from the analyzer. 2 detects the intensity of light transmitted from the transmission axis of
An optical property evaluation method, characterized in that the signal processing means calculates the light transmittance at the second transmission axis based on the intensity.   An optical element inspection method for detecting variations in optical characteristics within the plane of the polarizing element from optical characteristics obtained by the optical characteristic evaluation method according to claim 1.

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