JPS63281102A - Non-polarization beam splitter - Google Patents

Non-polarization beam splitter

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Publication number
JPS63281102A
JPS63281102A JP11763087A JP11763087A JPS63281102A JP S63281102 A JPS63281102 A JP S63281102A JP 11763087 A JP11763087 A JP 11763087A JP 11763087 A JP11763087 A JP 11763087A JP S63281102 A JPS63281102 A JP S63281102A
Authority
JP
Japan
Prior art keywords
layer
refractive index
beam splitter
substance
prism
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP11763087A
Other languages
Japanese (ja)
Inventor
Takehiro Nakae
武弘 中枝
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pentax Corp
Original Assignee
Asahi Kogaku Kogyo Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Asahi Kogaku Kogyo Co Ltd filed Critical Asahi Kogaku Kogyo Co Ltd
Priority to JP11763087A priority Critical patent/JPS63281102A/en
Publication of JPS63281102A publication Critical patent/JPS63281102A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To prevent the respective reflection factors and transmission factors of a P polarization and an S polarization from being different so much from each other, by constituting a multi-layer film of seven layers, and also, constituting it so that refractive indexes NH, NM and NL of a multi-substance are contained within a specific range. CONSTITUTION:The titled beam splitter is formed by providing a multi-layer film 2 on the slant face of a first transparent rectangular prism 1 of a refractive index NS, and also, joining a second rectangular prism 3 being equal substantially to the first rectangular prism 1, to the slant face of the first rectangular prism 1 by an adhesive agent 4. The multi-layer film 2 consists of a first layer - a seventh layer from the prism 1 side, and constituted of seven layer films consisting of the first layer and the seventh layer of a high refractive index substance (refractive index NH), the second layer, the fourth layer and the sixth layer of a middle refractive index substance (refractive index NM), and the third layer and the fifth layer of a low refractive index (reflective index NL), and the refractive indexes of each substance are as shown in the inequality I. In such a way, the respective reflection factors and transmission factors of a P polarization and an S polarization come to coincide roughly irrespective of a variation of the wavelength.

Description

【発明の詳細な説明】 a、技術分野 本発明は、例えば光デイスク装置の信号検出用光学系な
どに用いられる、近赤外域において、P偏光、S偏光の
反射率と透過率が約0.1010.90の非偏光ビーム
スプリッタに関するものである。
DETAILED DESCRIPTION OF THE INVENTION a. Technical Field The present invention is used, for example, in a signal detection optical system of an optical disk device, and has a reflectance and a transmittance of approximately 0.0 for P-polarized light and S-polarized light in the near-infrared region. 1010.90 non-polarizing beam splitter.

b、従来技術およびその問題点 従来、この種のビームスプリッタは、主に銀(Ag)等
の金属膜を誘電体で挾んだものが用いられていたが、吸
収によるエネルギー損失とか、耐久性が悪い等といった
問題があった。
b. Prior art and its problems Conventionally, beam splitters of this type have mainly used metal films such as silver (Ag) sandwiched between dielectric materials, but problems such as energy loss due to absorption and durability There were problems such as poor quality.

また、一般的に誘電体のみで構成されたコートは、エネ
ルギー損失もなく耐久性も良いが、実用上用いられる2
、4以下の屈折率を持つ2種類のコーテイング物質を用
いたビームスプリッタでは。
In addition, coats made only of dielectric materials generally have good durability with no energy loss, but they are not used in practical applications.
, in a beam splitter using two types of coating materials with a refractive index of 4 or less.

非偏光性が悪いものであった。It had poor non-polarizing properties.

第8図は、誘電体のみのコートを用いたビームスプリッ
タの分光特性を示す図であり、R5とTSはS偏光の反
射率と透過率を示し、RPとTPはP偏光の反射率と透
過率を示している。この分光特性図から明らかなように
、誘電体のみのコートを用いたビームスプリッタでは、
偏光によって反射率、透過率が異なってしまうものであ
った。
Figure 8 is a diagram showing the spectral characteristics of a beam splitter using only a dielectric coating, where R5 and TS indicate the reflectance and transmittance of S-polarized light, and RP and TP indicate the reflectance and transmittance of P-polarized light. It shows the rate. As is clear from this spectral characteristic diagram, in a beam splitter using only a dielectric coating,
The reflectance and transmittance differed depending on the polarization.

C0目的 本発明は1以上の点に鑑みなされたものであり、実用上
用いられる2、4以下の屈折率を持つ3種類以上のコー
テイング物質を用いることによって。
C0 Objective The present invention has been made in view of one or more points, by using three or more types of coating materials having a refractive index of 2 or 4 or less, which are used in practice.

反射率と透過率の比率が0.0410.96〜0.13
10.87程度の、即ちP偏光とS偏光のそれぞれの反
射率。
The ratio of reflectance and transmittance is 0.0410.96 to 0.13
The reflectance of each of P-polarized light and S-polarized light is about 10.87.

透過率が余り異ならない(はぼ一致している)非偏光ビ
ームスプリッタを提供しようとするものである。
The objective is to provide a non-polarizing beam splitter whose transmittances do not differ much (they are almost the same).

d、実施例の構成 本発明の非偏光ビームスプリッタは、第2図に示°すよ
うに。
d. Configuration of Example The non-polarizing beam splitter of the present invention is as shown in FIG.

屈折率NSの透明な第1直角プリズム1の斜面に多層膜
2を施すと共に、前記第1直角プリズムと実質的に等し
い第2直角プリズム3を接着剤4で前記第1直角プリズ
ムの斜面に接合して、なり。
A multilayer film 2 is applied to the slope of a transparent first right-angle prism 1 having a refractive index NS, and a second right-angle prism 3 that is substantially equal to the first right-angle prism is bonded to the slope of the first right-angle prism with an adhesive 4. Then, become.

前記多層膜2は、第1図に示すように、プリズム1側よ
り第1yII乃至第7層からなり、第1層。
As shown in FIG. 1, the multilayer film 2 consists of layers 1yII to 7th from the prism 1 side, with the first layer being the first layer.

第7層は高屈折率物質(屈折率NH) 、第2層。The seventh layer is a high refractive index material (refractive index NH), the second layer.

第4層、第6層は中屈折率物質(屈折率NM)、第3層
、第5層は低屈折率物質(屈折率NL)よりなる7層膜
で構成されており、前記各物質の屈折率は NL=1.38. N、〜1.635の時、1.99<
 NH<3.10NL=1.38. N、〜2.33の
時、1 、50 < N M < 2 、05N、〜1
.635. N、〜2.33の時、 1.15< NL
<1.44であることを特徴とし、また中屈折率物質の
光学的膜厚は基準設計波長をλ0としたとき0.36λ
0〜0.56λ。であることを特徴とする。
The fourth layer and the sixth layer are made of a medium refractive index material (refractive index NM), and the third layer and the fifth layer are made of a low refractive index material (refractive index NL). The refractive index is NL=1.38. When N, ~1.635, 1.99<
NH<3.10NL=1.38. N, ~2.33, 1, 50 < NM < 2, 05N, ~1
.. 635. When N, ~2.33, 1.15< NL
<1.44, and the optical thickness of the medium refractive index material is 0.36λ when the standard design wavelength is λ0.
0-0.56λ. It is characterized by

以下、基準設計波長λ。を78G、1.とじた時の具体
的な実施例のデータを示す、ここでHは高屈折率物質9
Mは中屈折率物質、Lは低屈折率物質を示し、カッコ内
は具体的な物質である。またR7・Oは780r1.に
おける屈折率、nd、、。は780n、における光学的
膜厚を示す。
Below is the standard design wavelength λ. 78G, 1. Shows data of specific examples when closed, where H is a high refractive index material 9
M indicates a medium refractive index material, L indicates a low refractive index material, and the specific material is in parentheses. Also, R7・O is 780r1. The refractive index at, nd, . indicates the optical film thickness at 780n.

〔実施例1〕 反射率/透過率=0.0470.96 物質     nvsa   n d7s。[Example 1] Reflectance/transmittance=0.0470.96 Substance nvsa nd7s.

プリズム (B K 7) 第1層  H(ZnS)    2.327 0.09
1λ。
Prism (B K 7) 1st layer H (ZnS) 2.327 0.09
1λ.

第2層  M (At、03)   t、635 0.
546λ。
2nd layer M (At, 03) t, 635 0.
546λ.

第3層  L (MgFz)    1.380 0.
154λ。
3rd layer L (MgFz) 1.380 0.
154λ.

第4層  M(^1,0.)   1.635 0.5
57λ。
4th layer M(^1,0.) 1.635 0.5
57λ.

第5層  L (MgFs)   1−380 0−1
54λ。
5th layer L (MgFs) 1-380 0-1
54λ.

第6層  M (Al、O,)   1.635 0.
546λ。
6th layer M (Al, O,) 1.635 0.
546λ.

第7層  H(ZnS)    2.327 0.09
1λ。
7th layer H (ZnS) 2.327 0.09
1λ.

プリズム (B K 7) 〔実施例2〕 反射率/透過率=0.1010.90 物質    nts。  nd、、。Prism (BK7) [Example 2] Reflectance/transmittance=0.1010.90 Substance nts. nd.

プリズム (BK7) 第1層  H(ZnS)    2.327 0.16
2λ。
Prism (BK7) 1st layer H (ZnS) 2.327 0.16
2λ.

第2層  M (Al□O,)   1.635  0
.429λ。
2nd layer M (Al□O,) 1.635 0
.. 429λ.

第3層  L (MgFt)    1.380 0.
286λ。
3rd layer L (MgFt) 1.380 0.
286λ.

第4層  M (A120.)   1.635  0
.476λ。
4th layer M (A120.) 1.635 0
.. 476λ.

第5層  L (MgF、)   1.380 0.2
86λ。
5th layer L (MgF,) 1.380 0.2
86λ.

第6M   M (Al、O,)   1.635 0
.429λ。
6th M M (Al, O,) 1.635 0
.. 429λ.

第7層  H(ZnS)    2.327  0.1
62λ。
7th layer H (ZnS) 2.327 0.1
62λ.

プリズム (B K 7) 〔実施例3〕 反射率/透過率=0.1310.87 物ff     n7@Ond、、。Prism (BK7) [Example 3] Reflectance/transmittance=0.1310.87 Things ff n7@Ond,,.

プリズム (B K 7) 第1層  H(ZnS)    2.327 0.20
3λ。
Prism (B K 7) 1st layer H (ZnS) 2.327 0.20
3λ.

第2層  M (AI、03)   1.635 0.
375λ6第3層  L (MgFP)   1−38
0 0−391λ。
2nd layer M (AI, 03) 1.635 0.
375λ6 3rd layer L (MgFP) 1-38
0 0-391λ.

第4層  M (AI、0.)   1.635 0.
353λ。
4th layer M (AI, 0.) 1.635 0.
353λ.

第5層  L (MgFz)   l−3800−39
1λ。
5th layer L (MgFz) l-3800-39
1λ.

第6層  M (Al□O,)   1.635 0.
375λ。
6th layer M (Al□O,) 1.635 0.
375λ.

第7層  H(ZnS)    2.327 0.20
3λ。
7th layer H (ZnS) 2.327 0.20
3λ.

プリズム (BK7) 〔実施例4〕 反射率/透過率=0.06510.935物質    
n?@+1   nd、IOプリズム (B K 7) 第1層  H(ZnS)    2.327 0.13
7λ。
Prism (BK7) [Example 4] Reflectance/transmittance = 0.06510.935 material
n? @+1 nd, IO prism (B K 7) 1st layer H (ZnS) 2.327 0.13
7λ.

第2層  M(A1□o、)   1,635  0.
444λ。
2nd layer M(A1□o,) 1,635 0.
444λ.

第3層  L (s、o、)   1.42  0.3
40λ。
3rd layer L (s, o,) 1.42 0.3
40λ.

第4層  M (A1.O,)   1.635 0.
385λ。
4th layer M (A1.O,) 1.635 0.
385λ.

第5層  L (sto、)   1.42  0.3
40λ。
5th layer L (sto,) 1.42 0.3
40λ.

第6層  M (Al□O,)   1,635 0.
444λ。
6th layer M (Al□O,) 1,635 0.
444λ.

第7層  H(ZnS)    2.327 0.34
0λ。
7th layer H (ZnS) 2.327 0.34
0λ.

プリズム (B K 7) 〔実施例5〕 反射率/透過率=0.0610.94 物質    n7■ndtsa プリズム (B K 7) 第1層  H(T翫0□”)   2.0g   0.
244λ。
Prism (B K 7) [Example 5] Reflectance/Transmittance = 0.0610.94 Material n7■ndtsa Prism (B K 7) 1st layer H (T line 0□”) 2.0g 0.
244λ.

第2層  M (Al、0.)   1.635 0.
393λ。
2nd layer M (Al, 0.) 1.635 0.
393λ.

第3層  L (MgFz)   1.38  0−2
72λ。
3rd layer L (MgFz) 1.38 0-2
72λ.

第4層  M (Al、0.)   1.635 0.
482λ。
4th layer M (Al, 0.) 1.635 0.
482λ.

第5層  L (MgFt)   1−38  0−2
72λ。
5th layer L (MgFt) 1-38 0-2
72λ.

第6層  M (A120.)   1.635 0.
393λ。
6th layer M (A120.) 1.635 0.
393λ.

第7層  H(7,0□)   2,08  0.24
4λ。
7th layer H (7,0□) 2,08 0.24
4λ.

プリズム (BK7) 尚、上記実施例1〜5の分光反射率9分光透過率を表わ
す特性図を、それぞれ第3〜7図に示した。
Prism (BK7) Characteristic diagrams representing the spectral reflectance and 9-spectral transmittance of Examples 1 to 5 are shown in FIGS. 3 to 7, respectively.

00作用 本発明は、上述のような特徴を有してなるものであるが
、前記NH* NMt NLがそれぞれ、N o <1
.99. NM<1.50.1.44< NLの場合に
は、P偏光の反射率がS偏光の反射率より低くなり、膜
厚等を調整しても、これを一致させることができず、逆
に3.10< NH,2,05< NM、 NL<1.
15の場合には、基準波長から波長が変動した時の分光
反射率の変化が、波長が長波長側に変動した時と短波長
側に変動した時とで異なるので、製造しにくくなるとい
う問題が生じ、望ましくない。
00 action The present invention has the above-mentioned characteristics, and each of the NH* NMt NL is N o <1
.. 99. If NM<1.50.1.44<NL, the reflectance of P-polarized light will be lower than that of S-polarized light, and even if you adjust the film thickness, etc., it will not be possible to make them match, and vice versa. 3.10<NH, 2,05<NM, NL<1.
In the case of No. 15, the change in spectral reflectance when the wavelength changes from the reference wavelength is different when the wavelength changes to the long wavelength side and when the wavelength changes to the short wavelength side, making it difficult to manufacture. occurs, which is undesirable.

また、中屈折率物質の光学的膜厚が、0.36λ。Further, the optical thickness of the medium refractive index material is 0.36λ.

以下の場合や、 0.56λ。以上の場合、非偏光性が
悪くなったり、前記同様1分光反射率の変化が基準波長
から長波長側と短波長側とで異なってしまうため、製造
しにくくなってしまう。
In the following cases, 0.56λ. In the above case, the non-polarizing property deteriorates, and the change in 1-spectral reflectance differs between the long wavelength side and the short wavelength side from the reference wavelength, making it difficult to manufacture.

f、効果 以上説明したように、本発明によれば、多層膜を7層で
構成すると共に、各物質の屈折率NH9NM、NLを、
それぞれ上記の範囲内にあるよにしたため、第3〜7図
の特性図から明らかなように、P偏光、S偏光のそれぞ
れの反射率、透過率は波長の変動によらず、はぼ一致し
た非偏光ビームスプリッタが提供できるものである。
f. Effect As explained above, according to the present invention, the multilayer film is composed of seven layers, and the refractive index of each substance NH9NM, NL is
Since each was set to be within the above range, as is clear from the characteristic diagrams in Figures 3 to 7, the reflectance and transmittance of P-polarized light and S-polarized light were almost the same, regardless of wavelength fluctuations. A non-polarizing beam splitter can be provided.

また、中屈折率物質の光学的膜厚を0.36λ0〜0.
56λ。とすれば、他の物質の膜厚を良好にコントロー
ルすることが可能となる。
Further, the optical film thickness of the medium refractive index material was set to 0.36λ0 to 0.36λ0.
56λ. If so, it becomes possible to control the film thickness of other substances well.

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

第1図は本発明によるコーティング(膜)の構成図であ
る。 第2図は本発明の非偏光ビームスプリッタの説明図であ
る。 第3.4,5,6.7図はそれぞれ本発明の実施例1,
2,3,4.5における分光反射率と分光透過率を示す
特性図である。 第8図は誘電体のみのコートを用いたビームスプリッタ
の分光特性図である。 1:第1直角プリズム   2:多層膜3:第2直角プ
リズム  4:接着剤 Ts=S偏光による分光透過率 Tp=P偏先による分光透過率 R8=S偏光による分光反射率 RP=P偏光による分光反射率 特許出願人   旭光学工業株式会社 車 1 図
FIG. 1 is a block diagram of a coating (film) according to the present invention. FIG. 2 is an explanatory diagram of the non-polarizing beam splitter of the present invention. 3.4, 5, and 6.7 are Embodiment 1 of the present invention, respectively.
FIG. 2 is a characteristic diagram showing spectral reflectance and spectral transmittance at No. 2, 3, and 4.5. FIG. 8 is a spectral characteristic diagram of a beam splitter using only a dielectric coating. 1: First right angle prism 2: Multilayer film 3: Second right angle prism 4: Adhesive Ts = Spectral transmittance by S polarized light Tp = Spectral transmittance by P polarization R8 = Spectral reflectance by S polarized light RP = By P polarized light Spectral reflectance patent applicant Asahi Optical Industry Co., Ltd. Vehicle 1 Figure

Claims (1)

【特許請求の範囲】 1 屈折率N_Sの透明な第1直角プリズムの斜面に多
層膜を施すと共に、前記第1直角プリズムと実質的に等
しい第2直角プリズムを接着剤で前記第1直角プリズム
の斜面に接合してなるビームスプリッタにおいて、 前記多層膜はプリズム側より第1層乃至第7層からなり
、第1層、第7層は高屈折率物質(屈折率N_H)、第
2層、第4層、第6層は中屈折率物質(屈折率N_M)
、第3層、第5層は低屈折率物質(屈折率N_L)より
なる7層膜で構成され、N_L=1.38、N_M=1
.635の時、1.99<N_H<3.10N_L=1
.38、N_H=2.33の時、1.50<N_M<2
.05N_M=1.635、N_H=2.33の時、1
.15<N_L<1.44であることを特徴とする非偏
光ビームスプリッタ。 2 基準設計波長をλ_0とした時中屈折率物質の光学
的膜厚が0.36λ_0〜0.56λ_0であることを
特徴とする特許請求の範囲第1項記載の非偏光ビームス
プリッタ。 3 高屈折率物質が硫化亜鉛(ZnS)、酸化チタニウ
ム(TiO_2)の何れかであり、 中屈折率物質が酸化アルミニウム(Al_2O_3)で
あり、 低屈折率物質がフッ化マグネシウム(MgF_2)、二
酸化ケイ素(SiO_2)の何れかであることを特徴と
する特許請求の範囲第1項または第2項記載の非偏光ビ
ームスプリッタ。
[Claims] 1. A multilayer film is applied to the slope of a transparent first right-angle prism having a refractive index N_S, and a second right-angle prism that is substantially equal to the first right-angle prism is bonded to the first right-angle prism with an adhesive. In the beam splitter bonded to the slope, the multilayer film is composed of the first layer to the seventh layer from the prism side, the first layer and the seventh layer are made of a high refractive index material (refractive index N_H), the second layer, and the third layer are made of a high refractive index material (refractive index N_H). The 4th and 6th layers are medium refractive index materials (refractive index N_M)
, the third layer and the fifth layer are composed of a 7-layer film made of a low refractive index material (refractive index N_L), N_L=1.38, N_M=1
.. When 635, 1.99<N_H<3.10N_L=1
.. 38, when N_H=2.33, 1.50<N_M<2
.. 05N_M=1.635, N_H=2.33, 1
.. A non-polarizing beam splitter characterized in that 15<N_L<1.44. 2. The non-polarizing beam splitter according to claim 1, wherein the optical film thickness of the medium refractive index material is 0.36λ_0 to 0.56λ_0 when the reference design wavelength is λ_0. 3 The high refractive index substance is either zinc sulfide (ZnS) or titanium oxide (TiO_2), the medium refractive index substance is aluminum oxide (Al_2O_3), and the low refractive index substance is magnesium fluoride (MgF_2) or silicon dioxide. The non-polarizing beam splitter according to claim 1 or 2, characterized in that the non-polarizing beam splitter is made of any one of (SiO_2).
JP11763087A 1987-05-14 1987-05-14 Non-polarization beam splitter Pending JPS63281102A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11763087A JPS63281102A (en) 1987-05-14 1987-05-14 Non-polarization beam splitter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11763087A JPS63281102A (en) 1987-05-14 1987-05-14 Non-polarization beam splitter

Publications (1)

Publication Number Publication Date
JPS63281102A true JPS63281102A (en) 1988-11-17

Family

ID=14716474

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11763087A Pending JPS63281102A (en) 1987-05-14 1987-05-14 Non-polarization beam splitter

Country Status (1)

Country Link
JP (1) JPS63281102A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006079058A (en) * 2004-08-09 2006-03-23 Canon Inc Polarization beam splittering and projection apparatus having the same
JP2010185916A (en) * 2009-02-10 2010-08-26 Nippon Electric Glass Co Ltd Beam splitting film and beamsplitter using the same
CN110749950A (en) * 2019-11-29 2020-02-04 沈阳仪表科学研究院有限公司 Refractive index matched depolarized film system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006079058A (en) * 2004-08-09 2006-03-23 Canon Inc Polarization beam splittering and projection apparatus having the same
JP2010185916A (en) * 2009-02-10 2010-08-26 Nippon Electric Glass Co Ltd Beam splitting film and beamsplitter using the same
CN110749950A (en) * 2019-11-29 2020-02-04 沈阳仪表科学研究院有限公司 Refractive index matched depolarized film system
CN110749950B (en) * 2019-11-29 2021-11-12 沈阳仪表科学研究院有限公司 Refractive index matched depolarized film system

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