JP2009104023A - Polarizer and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizer of high polarization splitting efficiency wherein polarization splitting characteristics is improved and to provide the manufacturing method of the polarizer by which the polarizer can be easily and inexpensively mass-produced by using an optical thin film. <P>SOLUTION: In the polarizer 1, a plurality of rectangular poles 13, each of which is obtained by sticking hypotenuses of two glass materials 11, 12 having the cross-section of a right-angled triangle shape, are arranged in parallel to each other along a light incident surface 1a. A polarization splitting film 14 for splitting the incident light to two kinds of linearly polarized light is provided to a hypotenuse interface between the glass materials 11, 12 and an absorption film 15 for absorbing the linearly polarized light which is made incident after being split by the polarization splitting film 14 is provided to the right-angled interface of the rectangular pole 13 each of which is arranged in parallel to each other. Only one kind of p polarized light among light beams made incident on the light incident surface 1a of the polarizer 1 (s polarized light + p polarized light) is emitted from a light emitting surface 1b. The absorption film 15 comprises an antireflection layer and an absorption layer made of a dielectric film composed of at least one of Si, TiO<SB>x</SB>and Nb<SB>2</SB>O<SB>5</SB>. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polarizer using an optical thin film and a method for manufacturing the same.

A polarizer is a polarizing optical element for obtaining linearly polarized light from random light such as natural light (non-polarized light) and circularly polarized light. Absorbing polarizer, reflective polarizer, thin film polarizer, birefringent polarizer, etc. Various configurations of polarizers have been put into practical use. These polarizers are widely used in spectral filters (liquid crystal filters) used in high-resolution spectral cameras and fluorescent microscopes, various measuring instruments for obtaining polarization information of light, and polarization conversion elements constituting liquid crystal projectors. .
For example, a spectroscopic device using a liquid crystal panel in which one or a plurality of liquid crystal cells are sandwiched between a pair of polarizers has been proposed (see Patent Document 1). A polarization separation film having a predetermined repeating structure of a basic structure film composed of an optically transparent high refractive index layer having a predetermined refractive index with respect to incident light and a low refractive index layer between a plurality of transparent substrates. A polarizing beam splitter that is arranged and a polarizer that includes the polarizing beam splitter and aligns natural light in a specific polarization state have been proposed (see Patent Document 2).

Japanese Patent Laid-Open No. 2005-31007 JP 2003-172824 A

  In the polarizers shown in Patent Document 1 and Patent Document 2 or the like, an absorption polarizer that determines the polarization direction by absorbing polarized light in one polarization direction, or the incident angle dependence of the reflectance of the dielectric thin film A thin film type polarizer is used. Although it is possible to obtain these polarizers with a large area, there is a problem that the conversion efficiency (transmittance or reflectivity) is easily lost due to stray light such as scattering or reflection of incident light incident on the polarizer. Have. There is also a need for a polarizer that is easy to mass-produce and inexpensive.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The polarizer according to this application example is a polarizer that generates incident light into linearly polarized light, and a rectangular column in which two translucent substrates having a cross-sectional shape of a right triangle are bonded to each other on the oblique sides of each other, A polarization separation film that is arranged in parallel along the incident surface of incident light and separates the incident light into first linearly polarized light and second linearly polarized light at the interface of the oblique side of the translucent substrate. An absorption film that absorbs the first linearly polarized light that is separated and incident on the interface of the rectangular columns arranged in parallel with each other, and a light exit surface that emits the second linearly polarized light And.

  According to this, a plurality of rectangular pillars in which two light-transmitting substrates having cross-sectional shapes of right-angled triangles are bonded to each other on the oblique sides are arranged in parallel along the incident light incident surface, The separation of the incident light into two kinds of first linearly polarized light and second linearly polarized light at the oblique side interface of the base material, and the polarization separation film at the right angle interface of the rectangular columns arranged in parallel And an absorbing film that absorbs the incident first linearly polarized light, and the incident light (incident angle) is different in the absorbing film together with the linearly polarized light that is separated by the polarization separating film and incident. It is possible to absorb stray light caused by scattering or reflection of incident light incident on the light and to emit one type of second linearly polarized light from the polarizer. That is, a polarizer with high separation efficiency and improved polarization separation characteristics can be obtained.

[Application Example 2]
In the polarizer according to the application example described above, it is preferable that the absorption film includes a dielectric multilayer film and includes an absorption layer including at least one of a dielectric film of Si, TiO _x , and Nb ₂ O ₅ .
According to this, the absorption film formed at the interface of the rectangular column is made of a dielectric multilayer film, and includes an absorption layer made of at least one of the dielectric films of Si, TiO _x , and Nb ₂ O _5. In addition to the linearly polarized light incident after being separated by the polarization separation film, stray light due to scattering or reflection of incident light having different incident angles and incident on the polarizer can be absorbed.

[Application Example 3]
In the polarizer according to this application example, it is preferable that the absorption film includes the absorption layer and an antireflection layer.
According to this, since the absorption film formed at the interface of the rectangular column includes the absorption layer and the antireflection layer, both the transmittance and the reflectance are excellent light with values close to approximately 0 (zero). An absorption film having absorption performance is obtained. Therefore, stray light caused by scattering or reflection of incident light having different incident angles and incident on the polarizer can be absorbed together with linearly polarized light incident after being separated by the polarization separation film.

[Application Example 4]
A method for manufacturing a polarizer according to this application example includes a polarization separation film forming step of forming a polarization separation film that separates incident light into two types of linearly polarized light on one surface of a light-transmitting substrate, and a plurality of steps A glass block forming step of forming a glass block in which the surface of the translucent substrate on which the polarization separation film is formed is aligned in one direction and is sequentially stacked and bonded together, and the glass block is made of the glass A glass block cutting step of forming a plurality of element units by cutting along a plurality of substantially parallel cutting lines forming an angle of about 45 ° with the surface of the block, and on one surface of the plurality of element units Forming an absorption film that absorbs one of the two types of linearly polarized light, and forming the absorption unit on the element unit by aligning the surface of the element unit on which the absorption film is formed in one direction. Is An element block forming step of forming an element block in which the polarization separation film is positioned so as to be substantially in a straight line and are sequentially stacked and bonded together in the plate thickness direction; And an element block cutting step of cutting along a plurality of cutting lines substantially parallel to each other at an angle of °.

  According to this manufacturing method, a polarization separation film forming step for forming a polarization separation film for separating incident light into two types of linearly polarized light on one surface of the light transmissive substrate, and polarization of a plurality of light transmissive substrates A glass block forming process in which the surface on which the separation film is formed is aligned in one direction and is sequentially stacked and bonded in the thickness direction, and a plurality of cutting lines that are substantially parallel to each other and form an angle of about 45 ° with the surface of the glass block. A glass block cutting step for forming a plurality of element units by cutting along an absorption film forming step for forming an absorption film for absorbing one of two types of linearly polarized light on one surface of the plurality of element units; An element block forming step in which the polarization separation films formed on the element unit are positioned so as to be substantially in a straight line and are sequentially stacked and bonded together in the thickness direction, and the surface of the element block forms an angle of approximately 90 ° with each other. An element block cutting step that cuts along a plurality of cutting lines substantially parallel to the cross-section of the rectangular column bonded to each other between the hypotenuses of two translucent substrates having a right-angled triangular cross-section. It is possible to obtain a large number of polarizers each having a polarization separating film and an absorbing film that absorbs linearly polarized light that is separated and incident on the orthogonal interface between the rectangular columns arranged in parallel. That is, it is possible to obtain a polarizer that is easily mass-produced and that is inexpensive.

  Moreover, the polarizer of a desired plane size or / and thickness can be obtained easily by selecting suitably the board | plate thickness of a translucent board | substrate, the planar size of a translucent board | substrate, and the number of sheets to be used. Therefore, a large planar size polarizer or a thin thickness polarizer can be easily obtained, and it can be widely applied as a spectroscope for measuring polarization information of a measurement object having a large area and as a thin optical filter in various optical instruments. Can do.

Hereinafter, embodiments will be described with reference to the drawings.
Fig.1 (a) is a front view which shows typically the structure of the polarizer which concerns on this embodiment, FIG.1 (b) is a cross section which shows typically the polarizer in the AA cross section of Fig.1 (a). FIG. In these drawings, the dimensions and ratios of each component are different from actual ones for convenience of explanation.

  1 (a) and 1 (b), a polarizer 1 is a translucent substrate whose cross-sectional shape forms a right triangle and extends in the y direction shown in the front view (FIG. 1 (a)). The glass material 11 and the glass material 12 as a translucent base material extending in the y direction in the same right-angled triangle having the same cross-sectional shape as the glass material 11 are bonded together at the oblique sides of each other. Rectangular columns 13 are arranged in parallel along the light incident surface 1a and the light exit surface 1b, and form a rectangular shape in front view.

  A polarization separation film 14 is formed on the hypotenuse (hypotenuse interface) of the right triangle where the glass material 11 and the glass material 12 are bonded together. In addition, an absorption film 15 is formed on an interface (right angle interface) in which the rectangular columns 13 on which the glass material 11 and the glass material 12 are bonded are sequentially bonded in the x direction. Note that the distance between the light incident surface 1a and the light exit surface 1b, that is, the thickness dimension of the polarizer 1 in the direction of the light incident surface 1a can be arbitrarily set according to the device to be used. In such a case, about 1 mm to 5 mm is preferable.

  The angle formed by the hypotenuse interface where the glass material 11 and the glass material 12 are bonded to the light incident surface 1a and the light emitting surface 1b is approximately 45 °. Therefore, the cross-sectional shapes of the glass material 11 and the glass material 12 are each a right isosceles triangle. That is, the rectangular column 13 having the polarization separation film 14 formed on the oblique side interface functions as a polarization beam splitter having a substantially square cross section.

The glass material 11 and the glass material 12 that are adjacent to each other via the polarization separation film 14, and the rectangular columns 13 that are adjacent to each other via the absorption film 15 in the direction along the light incident surface 1 a and the light emitting surface 1 b are bonded to each other by an adhesive ( (Not shown) is attached (attached). As the adhesive, for example, a one-component epoxy or one-component acrylic ultraviolet curable adhesive that can be easily bonded and can withstand relatively high temperatures can be used. The thickness of the adhesive (adhesive layer) is, for example, about 10 μm.
In addition, it can replace with an adhesive agent and can use the direct joining method which apply | coats a silane coupling agent and / or irradiates an active energy ray for these bonding.

  The material of the glass material 11 and the glass material 12 will not be limited if it is a base material (translucent base material) which has translucency. Therefore, white plate glass, various optical glasses, borosilicate glass, blue plate glass, and the like can be used. The glass material 11 and the glass material 12 in this embodiment consist of white plate glass, for example.

The polarization separation film 14 is formed of a dielectric multilayer film. The dielectric multilayer film includes, for example, a low / medium refractive index layer made of SiO ₂ (silicon dioxide), MgF ₂ (magnesium fluoride), lanthanum aluminate, etc., TiO ₂ (titanium dioxide), Ta ₂ O ₅ (oxidation). Examples thereof include a multilayer film in which a high refractive index layer made of tantalum or the like is formed in a predetermined order and an optical film thickness. The polarization separation film 14 separates an incident light bundle (s-polarized light + p-polarized light) into an s-polarized partial light bundle (s-polarized light) and a p-polarized partial light bundle (p-polarized light). It has a function of reflecting polarized light and transmitting p-polarized light (polarization separation function).

The absorption film 15 includes, for example, an antireflection layer made of a dielectric film such as Ta ₂ O ₅ , SiO ₂ , Al ₂ O ₃ (aluminum oxide), lanthanum titanate, Si (silicon), TiO _x , Nb ₂ O _5. An absorption layer made of a dielectric film such as (niobium pentoxide) is composed of a dielectric multilayer film combined in a predetermined order and optical thickness. The absorption film 15 is an opaque film having transmittance and reflectance values of approximately 0 (zero) in a predetermined wavelength region, and absorbs polarized light mainly composed of s-polarized light that is reflected by the polarization separation film 14 and incident thereon. It has a light absorption function.

Note that TiO _x is a substance that is composed of tetrahedral coordination while Ti in the normal TiO ₂ crystal is octahedral hexacoordinate, and whose absorption vector can be displaced by the amount of Ti. Ta ₂ O ₅ is a substance that can be an absorption layer or a transparent dielectric layer depending on the film formation conditions (optical film thickness).
The polarization separation film 14 and the absorption film 15 are formed by depositing each dielectric material using a vacuum deposition method, a sputtering method, an ion plating method, or the like.

A specific film configuration of the polarization separation film 14 and the absorption film 15 will be described.
In addition, a film | membrane structure shows an example in the case of the polarization separation film 14 and the absorption film 15 suitable with respect to a visible light wavelength range (about 420 nm-about 680 nm).

  “Table 1” shows a film configuration of a polarization separation film having a polarization separation function in the visible light wavelength region, and “Table 2” shows a film configuration of an absorption film having a light absorption function in the visible light wavelength region. The film configuration of the polarization separation film is a design value at a design wavelength of 760 nm and an incident angle of 45 °, and the film configuration of the absorption film is a design value at a design wavelength of 865 nm and an incident angle of 0 °.

  In each table, the layer numbers constituting each multilayer film are shown. Film thickness, optical film thickness (nd), and physical film thickness (d (nm)). Layer No. Is expressed as one layer, two layers, three layers, ... in order from the surface side of the glass material 11 or glass material 12 to be formed.

偏光分離膜１４は、「表１」に示すように、ＳｉＯ₂を１層目として、２層目〜３６層目の間をＬａＡｌＯ₃（ランタンアルミネート）とＭｇＦ₂（フッ化マグネシウム）とがこの順序に交互に成膜されて、最上層をＳｉＯ₂とする３７層の誘電体多層膜で構成される。
一方、吸収膜１５は、「表２」に示すように、Ｔａ₂Ｏ₅（酸化タンタル）を１層目として、２層目にＳｉＯ₂、以後３層目〜８層目にＴａ₂Ｏ₅とＳｉＯ₂が交互に成膜され、９層目にＴｉＯ_x、そして最上層の１０層目にＳｉＯ₂よりなる１０層の誘電体多層膜で構成される。この誘電体多層膜中の９層目のＴｉＯ_x層において光吸収が行われる。

As shown in “Table 1”, the polarization separation film 14 includes SiO ₂ as the first layer, and LaAlO ₃ (lanthanum aluminate) and MgF ₂ (magnesium fluoride) between the second layer and the 36th layer. The films are alternately formed in this order, and are composed of a 37-layer dielectric multilayer film with the uppermost layer being SiO ₂ .
On the other hand, as shown in “Table 2”, the absorption film 15 has Ta ₂ O ₅ (tantalum oxide) as the first layer, SiO ₂ as the second layer, and Ta ₂ O _{5 as the} third to eighth layers thereafter. and SiO ₂ is deposited alternately, TiO _x 9-layer, and consists of a dielectric multilayer film 10 layers made of SiO ₂ is 10 layer of the top layer. Light absorption is performed in the ninth TiO _x layer in the dielectric multilayer film.

FIG. 2 and FIG. 3 show the polarization separation characteristics of the polarization separation film 14 thus configured and the light absorption characteristics of the absorption film 15.
FIG. 2 is a graph showing the wavelength dispersion characteristics of transmittance and reflectance of the polarization separation film (having a polarization separation function in the visible light wavelength region) shown in “Table 1”. FIG. It is a graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of an absorption film (having the light absorption function of visible light wavelength region) to show.

  The horizontal axis of the graph indicates the wavelength (nm) of incident light in the wavelength range of 400 nm to 750 nm, and the vertical axis indicates the transmittance (T (%)) of p-polarized light or the reflectance (R (%) of s-polarized light. )). Each of the diagrams a to d shown in each drawing is a diagram connecting plot points for every 1 nm in the wavelength region of 400 nm to 750 nm obtained by calculation.

  In FIG. 2, the transmittance of p-polarized light in the visible light wavelength region (about 420 nm to 680 nm) of the polarization separation film 14 shown by the diagram a is 99.68% on average and 98.76 even if it is the minimum value. %, And has excellent transmission performance. On the other hand, the reflectance of the s-polarized light shown in the diagram b is 99.44% on average and 98.95% even on the minimum, and has excellent reflection performance.

  On the other hand, in FIG. 3, the average value of the transmittance in the visible light wavelength region (about 420 nm to 680 nm) of the absorption film 15 shown in the diagram c is 0.16%, and the average value of the reflectance shown in the diagram d is 0. It is 54%, the transmittance and the reflectance both show values close to 0 (zero), and have excellent light absorption performance.

  Next, the operation of the incident light that enters the polarizer 1 configured as described above will be described.

  In FIG. 1B, the light bundle (s-polarized light + p-polarized light) incident on the light incident surface 1a of the polarizer 1 along the system optical axis AL is formed at the hypotenuse interface between the glass material 11 and the glass material 12. Two partial beam bundles of the s-polarized light as the first linearly polarized light and the p-polarized light as the second linearly polarized light are incident on the polarized light separating film 14 at an incident angle of about 45 °. Separated. Then, the p-polarized light separated in the polarization separation film 14 passes through the polarization separation film 14 and travels toward the light exit surface 1b. On the other hand, the s-polarized light separated in the polarization separation film 14 is reflected by the polarization separation film 14 toward the absorption film 15 formed at the right-angle interface, and is incident on the absorption film 15 at an incident angle of approximately 0 °. And absorbed by the absorption film 15. That is, only one type of p-polarized light (linearly polarized light) is incident on the light incident surface 1a of the polarizer 1 and is approximately parallel to the system optical axis AL from the light exit surface 1b. Injected in the direction.

  The absorption film 15 also absorbs part of the p-polarized light that is reflected without being transmitted by the polarization separation film 14, or stray light that is incident on the light incident surface 1a and scattered in the glass material 11 and the glass material 12. Is done. Furthermore, s-polarized light out of a small amount of a part of the polarized light that is transmitted through the absorption film 15 without being absorbed by the absorption film 15 is formed at the hypotenuse interface between the adjacent glass material 11 and glass material 12. After entering the polarization separation film 14, the light is reflected by the polarization separation film 14, travels toward the light incident surface 1a, and is emitted from the light incident surface 1a.

  On the other hand, the p-polarized light is incident on the polarization separation film 14 formed on the oblique side interface between the adjacent glass material 11 and the glass material 12, and then transmitted through the polarization separation film 14 and formed on the adjacent right-angle interface. It goes to the absorption film 15 and is absorbed by the absorption film 15. Therefore, the polarizer 1 with improved polarization separation characteristics and high conversion efficiency can be obtained.

Next, a manufacturing method of the polarizer 1 configured as described above will be described.
4 and 5 are process cross-sectional views showing main processes for manufacturing the polarizer according to the present embodiment. In these drawings, the dimensions and ratios of each component are different from actual ones for convenience of explanation.

  First, in the process shown in FIG. 4A, a plurality of glass plates 111 as a light-transmitting substrate made of white glass having the same rectangular outer shape and the same predetermined thickness are prepared, and each glass plate is prepared. A polarization separation film 14 is formed on one of the two surfaces 111 (polarization separation film forming step). In addition, the predetermined thickness of the glass plate 111 in this embodiment is about 3 mm, for example.

The polarization separation film 14 is composed of the lanthanum aluminate in the second layer, and the MgF ₂ and lanthanum aluminate alternately in the third to thirty-sixth layers, with the SiO ₂ shown in “Table 1” as the first layer. A 37-layer dielectric multilayer film having SiO _{2 as} the uppermost layer is formed. The polarization separation film 14 is formed by using a dielectric material, such as a vacuum deposition method, a sputtering method, or an ion plating method.

This glass plate 111 forms the columnar glass material 11 and the glass material 12 (rectangular column 13) whose cross-sectional shape later formed a right triangle.
In the subsequent drawings including FIG. 4A and FIG. 5, the glass plate 111 is shown by an omitted number different from the actual number.

4B, the plurality of glass plates 111 on which the polarization separation film 14 has been formed in the polarization separation film formation step are arranged on one side of each glass plate 111 on which the polarization separation film 14 is formed. Aligned in the direction and sequentially stacked in the plate thickness direction, an ultraviolet curable adhesive (not shown) is applied to each interface, and the glass plates 111 are bonded to each other (glass block forming step).
The ultraviolet curable adhesive applied to the interface is cured by irradiating light (ultraviolet light) such as a chemical lamp or a high pressure mercury lamp. As a result, a plurality of glass plates 111 are overlapped in the plate thickness direction, and a glass block 112 in which the polarization separation film 14 is disposed at the overlapping interface is formed.

In the step shown in FIG. 4C, the glass block 112 formed in the glass block forming step is cut along a plurality of cutting lines CL1 (shown by alternate long and short dash lines in the drawing) (glass). Block cutting process).
The angle α that the cutting line CL1 forms with the surface of the glass plate 111 is approximately 45 °, and the interval between the cutting lines CL1 on the surface of the glass plate 111 is the cross-sectional shape of the glass plate 111 that later constitutes the light incident surface 1a. Is the length of the side of the right triangle.
From the glass block 112 cut along the cutting line CL1, a plurality of element units 113 having a region shape indicated by dots in the drawing are cut out.

And although not shown as a process, the absorption film 15 is formed on one surface of the two surfaces of the element unit 113 cut out in the glass block cutting process (absorption film formation process). The absorption film 15 formed on the surface of the element unit 113 is composed of Ta ₂ O ₅ shown in “Table 2” as the first layer, SiO ₂ as the second layer, Ta ₂ O _{5 as the} third layer, and four layers. SiO ₂ eyes, Ta ₂ O ₅ in the fifth layer, SiO ₂ to 6 th layer, the seventh layer to Ta ₂ O _5, 8 th layer to SiO _2, 9-layer to TiO _x, 10-layer top layer consisting SiO _2, of 10 layer dielectric multilayer film SiO ₂ is formed. The absorption film 15 is formed by using each dielectric material using a vacuum deposition method, a sputtering method, an ion plating method, or the like.
5A, a plurality of element units 113 having the absorption film 15 formed on one surface are prepared (element unit preparation process).

In the step shown in FIG. 5B, the plurality of element units 113 prepared in the element unit preparation step are aligned in the plate thickness direction with the surface on which the absorption film 15 of each element unit 113 is formed aligned in one direction. Are stacked one after another, and an ultraviolet curable adhesive (not shown) is applied to each interface to bond the element units 113 together (element block forming step).
When the element units 113 are bonded to each other, the plurality of polarization separation films 14 formed on each element unit 113 are positioned and overlapped so as to be substantially in a straight line.

  The ultraviolet curable adhesive applied to the interface is cured by irradiating light (ultraviolet light) such as a chemical lamp or a high pressure mercury lamp. Thereby, a plurality of element units 113 are overlapped with each other in the plate thickness direction, and an element block 114 in which the absorption film 15 is disposed at the overlapping interface is formed.

In the step shown in FIG. 5C, the element block 114 formed in the element block forming step is cut along a plurality of cutting lines CL2 (shown by alternate long and short dash lines in the figure) that are substantially parallel to each other (elements). Block cutting process).
The cutting line CL2 that cuts the element block 114 has an angle β that is substantially equal to the surface of the element block 114 for each surface position of the polarization separation film 14 formed in the element unit 113 positioned at the uppermost stage that forms the element block 114. Cut to 90 °. A plurality of region-shaped polarizers 1 indicated by dots in the drawing are cut out from the element block 114 cut along the cutting line CL2 to complete the polarizer 1. The thickness in the cut plane direction of the polarizer 1 cut and cut along the cutting line CL2 is about 3 mm.

  The completed polarizer 1 is a rectangle in which the polarization separation film 14 and the glass material 11 and the glass material 12 are bonded to each other on the oblique side interface where the glass material 11 and the glass material 12 whose cross-sectional shapes form a right triangle are bonded to each other. An absorption film 15 is provided at a right-angle interface where the columns 13 are sequentially bonded, and only p-polarized light (linearly polarized light) out of the light bundle (s-polarized light + p-polarized light) incident on the light incident surface 1a is emitted. It has a function of emitting light from the surface 1b in a direction substantially parallel to the system optical axis AL (see FIG. 1).

  In addition, although the manufacturing method of the polarizer 1 demonstrated only the main processes, after the glass block cutting process and an element block cutting process, each cutting | disconnection of the element unit 113 formed by cutting each block and the polarizer 1 is carried out. It is preferable to adjust the flatness and surface accuracy of the cut surface by polishing the surface using a single-side polishing device or a double-side polishing device.

  Further, the completed polarizer 1 may be provided with an antireflection (AR) layer on at least one surface or both surfaces. Since the polarizer 1 is composed of all inorganic substances and has excellent light resistance and heat resistance, the polarizer 1 can be heat-treated at a high temperature when forming the AR film. For example, silicon dioxide, titanium oxide, etc. A broadband AR film can be formed by depositing or sputtering a material.

  Furthermore, although the manufacturing method of the polarizer 1 has been described in the case where the polarizer 1 shown in FIG. 1 is completed by cutting the element block 114 along a plurality of cutting lines CL2, the manufacturing method of the glass plate 111 to be prepared is as follows. The plane size and the number of sheets can be appropriately set according to the desired size of the polarizer. Therefore, in this case, after cutting the element block 114 along the plurality of cutting lines CL2, it is preferable to perform cutting and polishing of the cut surface into a predetermined size or a predetermined outer shape.

Furthermore, the polarizer 1 can also be configured as follows.
In the element block forming step shown in FIG. 5B, an element block 114 is formed by temporarily adhering the element units 113 using an adhesive or the like instead of the ultraviolet curable adhesive. Then, the element block 114 is cut along a plurality of cutting lines CL2 substantially parallel to each other in the element block cutting step shown in FIG. 5 (c), and then the pressure-sensitive adhesive layer temporarily bonded from the cut polarizer 1 is peeled off. Thus, the light is separated into a plurality of rectangular pillars 13 each having a polarization separation film 14 at the oblique interface and having an absorption film 15 formed on one surface of the right-angle interface. Then, a predetermined number of rectangular pillars 13 are arranged in parallel with the direction of the formed absorption film 15 aligned, and then the outer peripheral portion is integrally fixed with a holder or the like to complete the polarizer 1 having a desired plane size. According to this configuration, the polarizers 1 having different plane sizes can be easily obtained by arranging the predetermined number of rectangular pillars 13 in parallel on the holders having different sizes.

The polarizer 1 configured and manufactured in this manner can obtain a function of emitting p-wave or s-wave polarized light with respect to incident non-polarized light by changing the arrangement direction of the polarizer 1.
FIG. 14 (a) is a schematic view showing the front, top and side surfaces of the completed polarizer in a lump, and FIG. 14 (b) is 90 ° with respect to the front view of the polarizer shown in FIG. 14 (a). It is a schematic diagram which shows the front surface, the upper surface, and the side surface of the state which rotated the angle collectively.

  As described above, in FIG. 14 (a), the polarizer 1 is used by arranging the direction in which the columnar glass materials 11 and 12 extend in the y-axis direction, so that the light is substantially parallel to the system optical axis. Unpolarized light incident on the incident surface 1a can be emitted as polarized light of p-waves (TM waves) whose electric field is horizontal to the light incident surface 1a.

On the other hand, the polarizer 1 is rotated 90 ° to the right, and as shown in FIG. 14B, the direction in which the columnar glass materials 11 and 12 constituting the polarizer 1 extend is the x-axis direction. By arranging and using, unpolarized light that is incident on the light incident surface 1a substantially parallel to the system optical axis and s-wave (TE wave) polarized light whose electric field is perpendicular to the light incident surface 1a are emitted. be able to.
The rotation direction of the polarizer 1 may be either right rotation or left rotation.

  The polarizer 1 described above is transmitted as an optical element that emits one type of p-polarized light or s-polarized light from incident light (s-polarized light + p-polarized light). It can be preferably used in an illumination optical system such as a projection projector or a reflection projector. In such a projector, in particular, the light resistance can be further improved by using it as a polarizer for emitting blue light having a short wavelength and high power.

  Further, the polarizer 1 is manufactured by arranging a plurality of rectangular pillars 13 in which a glass material 11 and a glass material 12 having a right-angled isosceles triangle cross section are bonded to each other along the oblique sides, along the light incident surface 1a. Therefore, it is possible to easily obtain a thin polarizer 1 having a large size (wide area) and being thin. Thereby, it can use suitably as a spectroscope which measures the polarization information of the measurement object which has a wide area, an optical filter in various optical instruments, etc.

  As described above, in the polarizer 1 of the present embodiment, a plurality of rectangular pillars 13 in which two glass materials 11 and 12 having a right-angled cross section are bonded to each other at the oblique sides are arranged in parallel along the light incident surface 1a. The polarized light separating film 14 is arranged to separate incident light into two kinds of linearly polarized light at the oblique side interface of the glass materials 11 and 12, and the polarized light separating film 14 is incident on the right angle interface of the rectangular pillars 13 arranged in parallel. The absorption film 15 that absorbs the linearly polarized light to be incident on the polarizer 1 with the incident direction (incident angle) being different from the linearly polarized light that is separated by the polarization separation film 14 and incident on the absorption film 15. It is possible to absorb stray light due to scattering or reflection of incident light and to emit one type of linearly polarized light (p-polarized light) from the polarizer 1. That is, it is possible to obtain the polarizer 1 having high separation efficiency with improved polarization separation characteristics over the visible light wavelength region of random light such as incident natural light (non-polarized light) and circularly polarized light.

Further, the absorption film 15 is made of a dielectric multilayer film including an absorption layer made of at least one of Si, TiO _x , and Nb ₂ O ₅ , so that it is separated by the polarization separation film 14 and incident. In addition to the s-polarized light, stray light caused by scattering or reflection of incident light having different incident angles and entering the polarizer 1 can be absorbed. Further, since the absorption film 15 includes the absorption layer and the antireflection layer, the absorption film 15 having excellent light absorption performance with a value close to 0 (zero) in both transmittance and reflectance is obtained. It is done.

  Further, the manufacturing method of the polarizer 1 includes a polarization separation film forming step of forming the polarization separation film 14 on one surface of the glass plate 111 and a surface on which the polarization separation films 14 of the plurality of glass plates 111 are formed. A glass block forming step in which the glass block is aligned in the direction and laminated in the thickness direction and bonded together, and a plurality of cutting lines CL1 are cut along a plurality of substantially parallel cutting lines CL1 forming an angle of about 45 ° with the surface of the glass block 112. The glass block cutting step for forming the element unit 113, the absorption film forming step for forming the absorption film 15 on one surface of the plurality of element units 113, and the polarization separation film 14 formed on the element unit 113 are substantially in a straight line. The element block forming step in which the element blocks are positioned and sequentially overlapped in the thickness direction and bonded together, and the surface of the element block 114 forms an approximately 90 ° angle with each other. An element block cutting step that cuts along a plurality of cutting lines CL2 in a row, so that the oblique side interface of the rectangular column 13 bonded by the oblique sides of the two glass materials 11 and 12 having a right-angled triangle cross section A large number of polarizers 1 in which the absorption film 15 is formed at the right-angle interface between the polarization separation film 14 and the rectangular pillars 13 arranged in parallel can be obtained at a time. That is, it is possible to obtain the polarizer 1 that can be easily mass-produced and is inexpensive. Furthermore, the manufacturing method of the polarizer 1 is the polarizer 1 of a desired plane size or / and thickness by selecting suitably the plate | board thickness of the glass materials 11 and 12, the plane size of the glass materials 11 and 12, and the number of sheets to be used. Can be easily obtained. Therefore, a polarizer 1 having a large plane size or a polarizer 1 having a small thickness can be easily obtained, and is widely applied as a spectroscope for measuring polarization information of a measurement object having a large area and a thin optical filter in various optical instruments. can do.

  It should be noted that, in the above-described embodiment, even if the form is exemplified as the following modification, it is possible to obtain the same effect as the present embodiment.

(Modification 1)
In the above embodiment, the polarization separation film 14 and the absorption film 15 formed on the polarizer 1 have been described as having a polarization separation function and a light absorption function in the visible light wavelength region. It can be set as the film | membrane structure substantially corresponding to a light wavelength range, a green light wavelength range, or a red light wavelength range. The polarizer 1 having the polarization separation film 14 and the absorption film 15 corresponding to each color light wavelength region is used for the purpose of, for example, preventing crosstalk between the color lights or increasing the contrast in a transmission projector or the like. It can be arranged and used on the light exit side of each color light LCD.

  “Table 3” shows the film configuration of the polarization separation film having the polarization separation function in the blue light wavelength region, and “Table 4” shows the film configuration of the absorption film having the light absorption function in the blue light wavelength region. The film configuration of the polarization separation film 14 is a design value at a design wavelength of 485 nm and an incident angle of 45 °, and the film configuration of the absorption film 15 is a design value at a design wavelength of 485 nm and an incident angle of 0 °.

  In each table, the layer numbers constituting each multilayer film are shown. Film thickness, optical film thickness (nd), and physical film thickness (d (nm)). Layer No. Is expressed as one layer, two layers, three layers, ... in order from the surface side of the glass material 11 or glass material 12 to be formed. This also applies to “Table 5” to “Table 10” shown below.

偏光分離膜１４は、「表３」に示すように、Ｔａ₂Ｏ₅（酸化タンタル）を１層目として、Ｔａ₂Ｏ₅とＳｉＯ₂とが交互に成膜されて、最上層をＳｉＯ₂とする２４層の誘電体多層膜で構成される。
一方、吸収膜１５は、「表４」に示すように、Ｔａ₂Ｏ₅（酸化タンタル）を１層目として、２層目にＳｉＯ₂、３層目にＴａ₂Ｏ₅、４層目にＳｉＯ₂、５層目にＴｉＯ_x、そして最上層の６層目にＳｉＯ₂よりなる、６層の誘電体多層膜で構成される。この誘電体多層膜中の５層目のＴｉＯ_x層において光吸収が行われる。

As shown in “Table 3”, the polarization separation film 14 has Ta ₂ O ₅ (tantalum oxide) as the first layer, Ta ₂ O ₅ and SiO ₂ are alternately formed, and the uppermost layer is made of SiO _2. It is comprised with 24 dielectric multilayer films.
On the other hand, as shown in “Table 4”, the absorption film 15 is composed of Ta ₂ O ₅ (tantalum oxide) as the first layer, SiO ₂ as the second layer, Ta ₂ O _{5 as the} third layer, and Ta 4 O as the fourth layer. The dielectric layer is composed of 6 layers of SiO ₂ , TiO _{x as the} fifth layer, and SiO _{2 as} the uppermost layer. Light absorption is performed in the fifth TiO _x layer in the dielectric multilayer film.

FIG. 6 and FIG. 7 show the polarization separation characteristics of the polarization separation film 14 thus configured and the light absorption characteristics of the absorption film 15.
FIG. 6 is a graph showing the wavelength dispersion characteristics of transmittance and reflectance of the polarization separation film 14 having the polarization separation function in the blue light wavelength region shown in “Table 3”, and FIG. 7 is shown in “Table 4”. It is a graph which shows the wavelength dispersion characteristic of the transmittance | permeability and the reflectance of the absorption film 15 which has the light absorption function of a blue light wavelength range.

  The horizontal axis of the graph indicates the wavelength (nm) of incident light in the wavelength region of 400 nm to 500 nm, and the vertical axis indicates the transmittance (T (%)) of p-polarized light or the reflectance (R (%) of s-polarized light. )). Each of the diagrams e to h shown in each drawing is a diagram connecting plot points for every 1 nm in the wavelength region 400 nm to 500 nm obtained by calculation.

In FIG. 6, the transmittance of p-polarized light in the polarization separation film 14 shown by the line e and the reflectance of s-polarized light shown by the line f are 99% or more in the blue light wavelength region of 429 nm to 466 nm. And has excellent transmission performance and reflection performance in the blue light wavelength region.
On the other hand, in FIG. 7, the transmittance of the absorption film 15 indicated by the line g and the reflectance indicated by the line h are both 0.5% or less in the blue light wavelength range corresponding to the polarization separation film 14 429 nm to 466 nm. And has excellent light absorption performance in the blue light wavelength region.

  “Table 5” shows the film configuration of the polarization separation film having the polarization separation function in the green light wavelength region, and “Table 6” shows the film configuration of the absorption film having the light absorption function in the green light wavelength region. The film configuration of the polarization separation film 14 is a design value at a design wavelength of 550 nm and an incident angle of 45 °, and the film configuration of the absorption film 15 is a design value at a design wavelength of 555 nm and an incident angle of 0 °.

偏光分離膜１４は、「表５」に示すように、ＴｉＯ₂を１層目として、ＴｉＯ₂とＳｉＯ₂とが交互に成膜されて、最上層をＳｉＯ₂とする２４層の誘電体多層膜で構成される。
一方、吸収膜１５は、「表６」に示すように、Ｔａ₂Ｏ₅（酸化タンタル）を１層目として、２層目にＳｉＯ₂、３層目にＴａ₂Ｏ₅、４層目にＳｉＯ₂、５層目にＴｉＯ_x、そして最上層の６層目にＳｉＯ₂よりなる、６層の誘電体多層膜で構成される。この誘電体多層膜中の５層目のＴｉＯ_x層において光吸収が行われる。

As shown in Table 5, the polarization separation film 14 is a 24-layer dielectric multilayer in which TiO ₂ is the first layer, TiO ₂ and SiO ₂ are alternately formed, and the uppermost layer is SiO _2. Consists of a membrane.
On the other hand, as shown in “Table 6”, the absorption film 15 has Ta ₂ O ₅ (tantalum oxide) as the first layer, SiO ₂ as the second layer, Ta ₂ O _{5 as the} third layer, and Ta ₂ O _{5 as} the fourth layer. The dielectric layer is composed of 6 layers of SiO ₂ , TiO _{x as the} fifth layer, and SiO _{2 as} the uppermost layer. Light absorption is performed in the fifth TiO _x layer in the dielectric multilayer film.

FIG. 8 and FIG. 9 show the polarization separation characteristics of the polarization separation film 14 thus configured and the light absorption characteristics of the absorption film 15.
FIG. 8 is a graph showing the wavelength dispersion characteristics of transmittance and reflectance of the polarization separation film 14 having the polarization separation function in the green light wavelength region shown in “Table 5”, and FIG. 9 is shown in “Table 6”. It is a graph which shows the wavelength dispersion characteristic of the transmittance | permeability and the reflectance of the absorption film 15 which has the light absorption function of a green light wavelength range.

  The horizontal axis of the graph indicates the wavelength (nm) of incident light in the wavelength region of 450 nm to 600 nm, and the vertical axis indicates the transmittance (T (%)) of p-polarized light or the reflectance (R (%) of s-polarized light. )). Each of the diagrams i to l shown in each figure is a diagram connecting plot points for every 1 nm in a wavelength region of 450 nm to 600 nm obtained by calculation.

In FIG. 8, the transmittance of p-polarized light in the polarization separation film 14 shown by the line i and the reflectance of s-polarized light shown by the line j are 99% or more in the green light wavelength region of 526 nm to 560 nm. And has excellent transmission performance and reflection performance in the green light wavelength region.
On the other hand, in FIG. 9, the transmittance of the absorption film 15 indicated by the line k and the reflectance indicated by the line l are both 0.2% or less at 526 nm to 560 nm in the green light wavelength range corresponding to the polarization separation film 14. This value is excellent and has excellent light absorption performance in the green light wavelength region.

  “Table 7” shows the film configuration of the polarization separation film having the polarization separation function in the red light wavelength region, and “Table 8” shows the film configuration of the absorption film having the light absorption function in the red light wavelength region. The film configuration of the polarization separation film 14 is a design value at a design wavelength of 670 nm and an incident angle of 45 °, and the film configuration of the absorption film 15 is a design value at a design wavelength of 670 nm and an incident angle of 0 °.

偏光分離膜１４は、「表７」に示すように、ＴｉＯ₂を１層目として、ＴｉＯ₂とＳｉＯ₂とが交互に成膜されて、最上層をＳｉＯ₂とする２４層の誘電体多層膜で構成される。
一方、吸収膜１５は、「表８」に示すように、Ｔａ₂Ｏ₅（酸化タンタル）を１層目として、２層目にＳｉＯ₂、３層目にＴａ₂Ｏ₅、４層目にＳｉＯ₂、５層目にＴｉＯ_x、そして最上層の６層目にＳｉＯ₂よりなる、６層の誘電体多層膜で構成される。この誘電体多層膜中の５層目のＴｉＯ_x層において光吸収が行われる。

As shown in Table 7, the polarization separation film 14 is a 24-layer dielectric multilayer in which TiO ₂ is the first layer, TiO ₂ and SiO ₂ are alternately formed, and the uppermost layer is SiO _2. Consists of a membrane.
On the other hand, as shown in “Table 8”, the absorption film 15 has Ta ₂ O ₅ (tantalum oxide) as the first layer, SiO ₂ as the second layer, Ta ₂ O _{5 as the} third layer, and Ta ₂ O _{5 as} the fourth layer. The dielectric layer is composed of 6 layers of SiO ₂ , TiO _{x as the} fifth layer, and SiO _{2 as} the uppermost layer. Light absorption is performed in the fifth TiO _x layer in the dielectric multilayer film.

10 and 11 show the polarization separation characteristics of the polarization separation film 14 configured as described above and the light absorption characteristics of the absorption film 15.
FIG. 10 is a graph showing the wavelength dispersion characteristics of transmittance and reflectance of the polarization separation film 14 having the polarization separation function in the red light wavelength region shown in “Table 7”, and FIG. 11 is shown in “Table 8”. It is a graph which shows the wavelength dispersion characteristic of the transmittance | permeability and the reflectance of the absorption film 15 which has the light absorption function of a red light wavelength range.

  The horizontal axis of the graph indicates the wavelength (nm) of incident light in the wavelength region of 550 nm to 750 nm, and the vertical axis indicates the transmittance (T (%)) of p-polarized light or the reflectance (R (%) of s-polarized light. )). Each of the diagrams m to q shown in each figure is a diagram that connects plot points for every 1 nm in the wavelength region 550 nm to 750 nm obtained by calculation.

In FIG. 10, the transmittance of p-polarized light in the polarization separation film 14 shown by the line m and the reflectance of s-polarized light shown by the line n are 99% or more in the red light wavelength range of 610 nm to 673 nm. And has excellent transmission performance and reflection performance in the red light wavelength region.
On the other hand, in FIG. 11, the transmittance of the absorption film 15 indicated by the line p and the reflectance indicated by the line q are both 0.4% or less at 610 nm to 673 nm in the red light wavelength region corresponding to the polarization separation film 14. And has an excellent light absorption performance in the red light wavelength region.

(Modification 2)
In the above-described embodiment and Modification 1, the absorption film 15 formed on the polarizer 1 is composed of a six-layer dielectric multilayer film made of Ta ₂ O ₅ , SiO ₂ , and TiO _x materials. However, other materials such as Si (silicon), Al ₂ O ₃ (aluminum oxide), Nb ₂ O ₅ (niobium pentoxide), LaTiO ₃ (lanthanum titanate) can be used.

Another film configuration example of the absorption film 15 will be described by taking the absorption film having the light absorption function in the blue light wavelength region shown in the above “Modification 1” as an example.
“Table 9” shows another film configuration of the absorption film having the light absorption function in the blue light wavelength region, and “Table 10” shows still another film of the absorption film having the light absorption function in the blue light wavelength region. The configuration is shown. The film configuration of the absorption film 15 is a design value at a design wavelength of 485 nm and an incident angle of 0 °.

「表９」に示す吸収膜１５は、ＬａＴｉＯ₃（ランタンチタネート）を１層目として、２層目以降Ａｌ₂Ｏ₃、ＳｉＯ₂、ＬａＴｉＯ₃、ＳｉＯ₂、ＬａＴｉＯ₃、７層目にＳｉ、そして最上層の８層目にＳｉＯ₂よりなる、８層の誘電体多層膜で構成される。この誘電体多層膜中の７層目のＳｉ層において光吸収が行われる。
「表１０」に示す吸収膜１５は、Ｎｂ₂Ｏ₅（五酸化ニオブ）を１層目として、２層目にＳｉＯ₂、３層目にＮｂ₂Ｏ₅、４層目にＳｉＯ₂、５層目にＴｉＯ_x、そして最上層の６層目にＳｉＯ₂よりなる、６層の誘電体多層膜で構成される。この誘電体多層膜中の５層目のＴｉＯ_x層において光吸収が行われる。

The absorption film 15 shown in “Table 9” has LaTiO ₃ (lanthanum titanate) as the first layer, Al ₂ O ₃ , SiO ₂ , LaTiO ₃ , SiO ₂ , LaTiO ₃ , and the seventh layer with Si, The eighth uppermost layer is composed of an eight-layer dielectric multilayer film made of SiO ₂ . Light absorption is performed in the seventh Si layer in the dielectric multilayer film.
Absorbing film 15 shown in "Table 10", SiO _2, 5 Nb ₂ O ₅ and (niobium pentoxide) as a first layer, the Nb ₂ O _5, 4-layer to SiO _2, 3-layer as the second layer It is composed of a six-layer dielectric multilayer film composed of TiO _{x as} the layer and SiO _{2 as the} uppermost layer. Light absorption is performed in the fifth TiO _x layer in the dielectric multilayer film.

The light absorption characteristics of the absorption film 15 configured as described above are shown in FIGS.
FIG. 12 is a graph showing the wavelength dispersion characteristics of the transmittance and reflectance of another absorption film 15 having a light absorption function in the blue light wavelength range shown in “Table 9”. FIG. It is a graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of another absorption film 15 which has the light absorption function of the blue light wavelength range to show.

  The horizontal axis of each graph indicates the wavelength (nm) of incident light in the wavelength region of 400 nm to 500 nm, and the vertical axis indicates the transmittance of p-polarized light (T (%)) or the reflectance of s-polarized light (R ( %)). Each of the diagrams r to u shown in each drawing is a diagram connecting plot points for every 1 nm in the wavelength region 400 nm to 500 nm obtained by calculation.

In FIG. 12, the transmittance of the absorption film 15 indicated by the line r and the reflectance of the absorption film 15 indicated by the line s are 0.9% in the blue light wavelength region corresponding to the polarization separation film 14 429 nm to 466 nm. The following values are shown. In FIG. 13, the transmittance shown by the line t and the reflectance shown by the line u show values of 0.4% or less, and both have excellent light absorption performance in the blue light wavelength region.
In the second modification, the case where the absorption layer of the absorption film 15 is made of TiO _x and Si has been exemplified. However, Nb ₂ O ₅ (niobium pentoxide) or Ta ₂ O ₅ (tantalum oxide) is used as the absorption layer. The absorption film 15 can also be formed of the dielectric multilayer film. However, when Ta ₂ O ₅ is used, since the light absorption performance is low, it is necessary to form a thick dielectric film.

(A) is a front view which shows typically the structure of the polarizer which concerns on this embodiment, (b) is sectional drawing which shows typically the polarizer in the AA cross section of (a). The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of a polarization separation film having a polarization separation function in the visible light wavelength region. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of an absorption film which has a light absorption function of visible light wavelength region. Process sectional drawing which shows the main processes which manufacture the polarizer which concerns on this embodiment. Process sectional drawing which shows the main processes which manufacture the polarizer which concerns on this embodiment. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of a polarization separation film which has a polarization separation function of a blue light wavelength region. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of an absorption film which has a light absorption function of a blue light wavelength region. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of a polarization separation film which has a polarization separation function of a green light wavelength range. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of an absorption film which has a light absorption function of a green light wavelength range. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of a polarization separation film which has a polarization separation function of a red light wavelength region. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of an absorption film which has the light absorption function of a red light wavelength range. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of another absorption film which has the light absorption function of a blue light wavelength range. The graph which shows the wavelength dispersion characteristic of the transmittance | permeability and reflectance of another absorption film which has a light absorption function of a blue light wavelength range. (A) is a schematic diagram collectively showing the front, top and side surfaces of the completed polarizer, and (b) is a front view in a state rotated by an angle of 90 ° with respect to the front view of the polarizer shown in (a). The schematic diagram which shows an upper surface and a side surface collectively.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Polarizer, 1a ... Light incident surface, 1b ... Light emission surface, 11, 12 ... Glass material as translucent base material, 13 ... Rectangular column, 14 ... Polarization separation film, 15 ... Absorption film, 111 ... Transmission Glass plate as optical substrate, 112... Glass block, 113... Element unit, 114.

Claims (4)

A polarizer that creates incident light into linearly polarized light,
A plurality of rectangular pillars in which two translucent substrates having a right-angled cross-sectional shape are bonded to each other at the oblique sides are arranged in parallel along the incident surface of the incident light,
A polarization separation film that separates the incident light into the first linearly polarized light and the second linearly polarized light at the oblique side interface of the translucent substrate;
An absorbing film that absorbs the first linearly polarized light that is separated and incident on the interface of the rectangular columns arranged in parallel, and a light exit surface that emits the second linearly polarized light;
A polarizer characterized by comprising: The polarizer according to claim 1,
The polarizer is characterized in that the absorption film is made of a dielectric multilayer film and includes an absorption layer made of at least one of a dielectric film of Si, TiO _x , and Nb ₂ O ₅ . The polarizer according to claim 1 or 2, wherein
The polarizer according to claim 1, wherein the absorption film includes the absorption layer and an antireflection layer. A polarization separation film forming step of forming a polarization separation film that separates incident light into two types of linearly polarized light on one surface of the translucent substrate;
A glass block forming step of forming a glass block in which the surfaces on which the polarization separation films of the plurality of translucent substrates are formed are aligned in one direction and are sequentially stacked and bonded together;
Cutting the glass block along a plurality of cutting lines substantially parallel to each other at an angle of about 45 ° with the surface of the glass block to form a plurality of element units; and
An absorption film forming step of forming an absorption film that absorbs one of the two types of linearly polarized light on one surface of the plurality of element units;
The surfaces of the plurality of element units on which the absorption films are formed are aligned in one direction, and the polarization separation films formed on the element units are positioned so as to be substantially in a straight line, and are sequentially superimposed in the plate thickness direction. An element block forming step for forming an element block bonded together;
An element block cutting step for cutting the element block along a plurality of cutting lines substantially parallel to each other and forming an angle of about 90 ° with the surface of the element block;
A method for producing a polarizer, comprising:

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