JPH0738041B2 - Non-polarized beam splitter - Google Patents
Non-polarized beam splitterInfo
- Publication number
- JPH0738041B2 JPH0738041B2 JP61153065A JP15306586A JPH0738041B2 JP H0738041 B2 JPH0738041 B2 JP H0738041B2 JP 61153065 A JP61153065 A JP 61153065A JP 15306586 A JP15306586 A JP 15306586A JP H0738041 B2 JPH0738041 B2 JP H0738041B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- refractive index
- layer
- beam splitter
- component
- 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.)
- Expired - Lifetime
Links
- 239000000758 substrate Substances 0.000 claims description 14
- 239000010408 film Substances 0.000 description 58
- 238000002834 transmittance Methods 0.000 description 12
- 239000000126 substance Substances 0.000 description 11
- 230000003595 spectral effect Effects 0.000 description 7
- 239000011521 glass Substances 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 229910010413 TiO 2 Inorganic materials 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000001771 vacuum deposition Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- YPSXFMHXRZAGTG-UHFFFAOYSA-N 4-methoxy-2-[2-(5-methoxy-2-nitrosophenyl)ethyl]-1-nitrosobenzene Chemical compound COC1=CC=C(N=O)C(CCC=2C(=CC=C(OC)C=2)N=O)=C1 YPSXFMHXRZAGTG-UHFFFAOYSA-N 0.000 description 1
- 241001354532 Holozonia filipes Species 0.000 description 1
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 1
- 229910017768 LaF 3 Inorganic materials 0.000 description 1
- 229910002665 PbTe Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- -1 Tempax (trade name) Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000005331 crown glasses (windows) Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000012788 optical film Substances 0.000 description 1
- 239000005304 optical glass Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- SBIBMFFZSBJNJF-UHFFFAOYSA-N selenium;zinc Chemical compound [Se]=[Zn] SBIBMFFZSBJNJF-UHFFFAOYSA-N 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Inorganic materials [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 1
- 239000005361 soda-lime glass Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- OCGWQDWYSQAFTO-UHFFFAOYSA-N tellanylidenelead Chemical compound [Pb]=[Te] OCGWQDWYSQAFTO-UHFFFAOYSA-N 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
- G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
- G02B5/3041—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid comprising multiple thin layers, e.g. multilayer stacks
- G02B5/305—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid comprising multiple thin layers, e.g. multilayer stacks including organic materials, e.g. polymeric layers
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Elements Other Than Lenses (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、例えばビデイオ・デイスク装置やコンパクト
・デイスク装置などの光学系に用いられる無偏光ビーム
スプリツターに関するものである。Description: TECHNICAL FIELD The present invention relates to a non-polarizing beam splitter used in an optical system such as a video disc device or a compact disc device.
〔従来の技術〕 従来この種の無偏光ビームスプリツターとしたは、例え
ば特開昭58−190906号公報、特開昭58−208701号公報ま
たは特開昭58−208702号公報に記載されているように、
透明の基板に対し、それより屈折率の高い第１の物質
と、さらに高い第２の物質の２種を用い、それらを交互
に積層することにより、Ｐ成分とＳ成分それぞれの透過
率と反射率との比をコントロールするものがある。[Prior Art] Conventional non-polarizing beam splitters of this type are described in, for example, JP-A-58-190906, JP-A-58-208701, or JP-A-58-208702. like,
For a transparent substrate, two kinds of substances, a first substance having a higher refractive index and a second substance having a higher refractive index, are used, and by alternately stacking them, the transmittance and the reflection of the P component and the S component, respectively. There is one that controls the ratio with the rate.
上述した従来の技術によれば、第１の物質および第２の
物質の屈折率を適当に設定することにより、計算上、Ｐ
・Ｓ各成分の透過率と反射率との比を自在に設定でき、
その比を1:1にすることも可能である。According to the above-mentioned conventional technique, by setting the refractive indexes of the first substance and the second substance appropriately, P
・ The ratio of the transmittance and reflectance of each S component can be set freely,
It is also possible to make the ratio 1: 1.
しかし、実在する物質を用いて実際に従来Ｐ・Ｓ成分の
透過率と反射率との比が1:1となる無偏光ビームスプリ
ツターを製作しようとすると、計算上必要とされる屈折
率を有する物質が現実には見出し難い。また、仮に1:1
の特性に近い組合せが得られたとしても、その特性を満
足できる波長範囲が狭いため、製造条件、例えば成膜時
の真空蒸着装置内の圧力と基板温度、あるいは膜厚制御
上の誤差等により、希望波長において所望の特性から大
きくずれてしまい、製品としての歩留りも低下するとい
う問題があつた。However, if an attempt is made to manufacture a non-polarizing beam splitter with a conventional P / S component transmittance / reflectance ratio of 1: 1 using an existing substance, the refractive index required for calculation is calculated. It is difficult to find the substance that you have in reality. Also, assuming 1: 1
Even if a combination close to the characteristics of is obtained, since the wavelength range that can satisfy the characteristics is narrow, it may depend on the manufacturing conditions, such as the pressure and substrate temperature in the vacuum vapor deposition apparatus during film formation, or errors in film thickness control. However, there is a problem that the desired characteristics are largely deviated from the desired characteristics, and the yield as a product is reduced.
本発明は、相互に異なる屈折率nL，nM，nH（nL＜nM＜
nH）を有する３種の膜を、基板から遠い側から数えて奇
数層目が屈折率nLの膜、偶数層目が屈折率nMの膜または
nHの膜となるように多層に積層し、かつ屈折率ng,nL,n
M,nHを、それぞれ1.3＜ng＜4.0、1.3＜nL＜2.3、2.0＜n
M＜4.0および3.0＜nH＜6.0の範囲に設定したものであ
る。The present invention has different refractive indices n L , n M , n H (n L <n M <
n H ) are counted from the side far from the substrate, the odd-numbered layer has a refractive index n L , the even-numbered layer has a refractive index n M , or
Multilayered to have a film of n H and a refractive index of ng, nL, n
M and nH are 1.3 <ng <4.0, 1.3 <nL <2.3, 2.0 <n, respectively.
It is set in the range of M <4.0 and 3.0 <nH <6.0.
無偏光ビームスプリツターに入射した光は、一部は膜を
透過し、他はその膜の表裏で反射するが、反射は各層の
膜において直接光および反射光について生じ、理論的に
は無限級数的に繰り返される。そして最終的に入射側と
反対側に出射する光の総体を透過光、入射側に反射する
光の総体を反射光とするが、３種の異なる屈折率の組合
せにより、Ｐ・Ｓ各成分に対し、その透過率と反射率と
の比が1:1となる。Light incident on the unpolarized beam splitter partially passes through the film and is reflected on the front and back sides of the film, but reflection occurs for the direct light and the reflected light in each layer film, and theoretically an infinite series. Repeated. Finally, the total of the light emitted to the side opposite to the incident side is the transmitted light, and the total of the light reflected to the incident side is the reflected light. However, by combining three different refractive indices, P and S components On the other hand, the ratio between the transmittance and the reflectance is 1: 1.
（実施例１） 第２図は本発明の第１の実施例を示す無偏光ビームスプ
リツターの側面図である。同図において、無偏光ビーム
スプリツター1Aは、BK−７相当の屈折率ng＝1.51のガラ
スからなる平板状透明基板２の一主表面上に、多層膜3A
を形成したものである。(Embodiment 1) FIG. 2 is a side view of a non-polarization beam splitter showing a first embodiment of the present invention. In the figure, a non-polarized beam splitter 1A has a multilayer film 3A on one main surface of a flat transparent substrate 2 made of glass having a refractive index ng = 1.51 corresponding to BK-7.
Is formed.
多層膜3Aは、第１図に示すように、入射光４の入射側、
すなわち基板２に最も遠い側から数えて奇数層目、つま
り第１層，第３層および第５層を屈折率nL＝1.61のAl2O
3膜31とし、第２層を屈折率nH＝3.67のSi膜32、第４層
を屈折率nM＝2.24のTiO2膜33とした構成を有している。
本実施例は入射側媒質５を屈折率n0＝１の空気とし、設
計中心波長をλ０＝840nmとし、各層の膜厚（光学的膜
厚）をnd＝λ０/4＝210nmとしている。また、特にSi膜3
2については、成膜条件によつて生成される膜の屈折率
が異なるが、本実施例では各膜は真空蒸着法により形成
した。そのときの成膜条件は、真空蒸着装置内の圧力が
２×10-5〜５×10-5torr、基板温度が300〜350℃であつ
た。真空蒸着法の代りに、例えばスパツタリング法を使
用することも可能である。The multilayer film 3A is, as shown in FIG. 1, the incident side of the incident light 4,
That is, the odd-numbered layers counting from the side farthest from the substrate 2, that is, the first layer, the third layer, and the fifth layer are formed of Al 2 O having a refractive index n L = 1.61.
The third film 31 is used, the second layer is a Si film 32 having a refractive index n H = 3.67, and the fourth layer is a TiO 2 film 33 having a refractive index n M = 2.24.
This embodiment is an incident side medium 5 with the air of a refractive index n 0 = 1, the designed center wavelength is lambda 0 = 840 nm, the thickness of each layer (optical film thickness) as n d = λ 0/4 = 210nm There is. In addition, especially Si film 3
With respect to No. 2, although the refractive index of the film formed differs depending on the film forming conditions, each film was formed by the vacuum evaporation method in this example. The film forming conditions at that time were that the pressure in the vacuum vapor deposition apparatus was 2 × 10 −5 to 5 × 10 −5 torr and the substrate temperature was 300 to 350 ° C. Instead of the vacuum deposition method, it is also possible to use, for example, a sputtering method.
第３図は、このようにして形成した多層膜3Aの膜面に対
し、θ＝45°の入射角で入射光４を入射させた場合につ
いて、Ｐ・Ｓ各成分の分光特性を測定した結果を示すも
のである。同図において、（イ）はＰ成分の透過率Tp、
（ロ）は同じく反射率Rp、（ハ）はＳ成分の透過率Ts、
（ニ）は同じく反射率Rsを示し、700〜850nmの広い波長
範囲において、Ｐ成分とＳ成分とのそれぞれについて、
透過率と反射率との比がほぼ1:1の特性が得られてい
る。FIG. 3 shows the results of measuring the spectral characteristics of the P and S components when incident light 4 is incident on the film surface of the multilayer film 3A thus formed at an incident angle of θ = 45 °. Is shown. In the figure, (a) shows the transmittance T p of the P component,
Similarly, (b) is the reflectance R p , (c) is the transmittance T s of the S component,
Similarly, (d) shows the reflectance R s , and for each of the P component and the S component in a wide wavelength range of 700 to 850 nm,
The characteristic that the ratio between the transmittance and the reflectance is almost 1: 1 is obtained.
このように広い波長範囲で1:1の特性が得られることか
ら、製造条件等により多少の波長シフトが生じたとして
も、所望波長において1:1の特性から外れることはな
い。Since the 1: 1 characteristic can be obtained in such a wide wavelength range, even if a slight wavelength shift occurs due to manufacturing conditions or the like, it does not deviate from the 1: 1 characteristic at the desired wavelength.
（実施例２） 第４図は本発明の第２の実施例を示す断面図である。本
実施例の無偏光ビームスプリツター1Bは、第１実施例と
同様のBK−７ガラスからなる平板状透明基板２の入射側
主表面上に、多層膜3Bを形成したもので、多層膜3Bは、
第１層，第３層および第５層を屈折率nL＝1.61のAl2O3
膜31、第２層を屈折率nM＝2.24のTiO2膜33、第４層を屈
折率nH＝3.67のSi膜32とした構成、つまり第１実施例に
おいて第２層と第４層の膜を入れ換えた構成を有し、各
膜の光学的膜厚も設計中心波長λ０＝840nmに対してλ
０/4＝210nm、成膜条件も、真空蒸着装置内の圧力２×1
0-5〜５×10-5torr、基板温度300〜350℃と第１の実施
例と同様である。(Embodiment 2) FIG. 4 is a sectional view showing a second embodiment of the present invention. The non-polarizing beam splitter 1B of the present embodiment is formed by forming a multilayer film 3B on the incident side main surface of a flat transparent substrate 2 made of BK-7 glass similar to that of the first embodiment. Is
The first layer, the third layer and the fifth layer are made of Al 2 O 3 having a refractive index n L = 1.61.
The film 31, the second layer is a TiO 2 film 33 having a refractive index n M = 2.24, and the fourth layer is a Si film 32 having a refractive index n H = 3.67, that is, the second layer and the fourth layer in the first embodiment. The optical thickness of each film is λ with respect to the design center wavelength λ 0 = 840 nm.
0/4 = 210 nm, film formation conditions also, pressure 2 × 1 in the vacuum evaporation apparatus
The value is 0 -5 to 5 × 10 -5 torr and the substrate temperature is 300 to 350 ° C., which is the same as in the first embodiment.
上記構成において、入射側媒質（空気）５からθ＝45°
の入射角で入射光を入射させた場合について、Ｐ・Ｓ各
成分の分光特性を測定した結果を第５図に示す。同図に
おいて、（イ）がＰ成分の透過率Tp、（ロ）が同じく反
射率Rp、（ハ）がＳ成分の透過率Ts、（ニ）が同じく反
射率Rsを示す。第３図に示した第１の実施例に比較し
て、Ｓ成分については700〜850nmの波長範囲の両端部に
おいて透過率と反射率との開きがやや大きくなつている
が、Ｐ成分についてはきわめて良好な特性を有してい
る。In the above configuration, θ = 45 ° from the incident side medium (air) 5
FIG. 5 shows the results of measuring the spectral characteristics of the P and S components in the case where the incident light is incident at the incident angle of. In the figure, (a) shows the transmittance T p of the P component, (b) shows the reflectance R p of the same , (c) shows the transmittance T s of the S component, and (d) shows the reflectance R s . Compared to the first embodiment shown in FIG. 3, for the S component, the difference between the transmittance and the reflectance is slightly larger at both ends of the wavelength range of 700 to 850 nm, but for the P component, It has very good characteristics.
（実施例３） 第６図は本実施例の第３の実施例を示す断面図である。
本実施例の無偏光ビームスプリツター1Cは、第１の実施
例に対し、多層膜3Aの第５層を省略した４層構造の多層
膜3Cを有する点のみが異なる。すなわち多層膜3Cは、第
１層および第３層のAl2O3膜31（屈折率nL＝1.61）、第
２層のSi膜32（屈折率nH＝3.67）ならびに第４層のTiO2
膜33（屈折率nM＝2.24）からなり、光学的膜厚はλ０/4
＝210nm、成膜条件も第１の実施例と全く同様である。(Embodiment 3) FIG. 6 is a sectional view showing a third embodiment of this embodiment.
The non-polarizing beam splitter 1C of the present embodiment differs from the first embodiment only in that it has a multilayer film 3C having a four-layer structure in which the fifth layer of the multilayer film 3A is omitted. That is, the multilayer film 3C is composed of the Al 2 O 3 film 31 (refractive index n L = 1.61) of the first layer and the third layer, the Si film 32 of the second layer (refractive index n H = 3.67) and the TiO of the fourth layer. 2
Film 33 made of (refractive index n M = 2.24), the optical thickness of lambda 0/4
= 210 nm, and the film forming conditions are exactly the same as in the first embodiment.
本実施例においても、入射側媒質（空気）５からθ＝45
°の入射角で入射光を入射させた場合について、Ｐ・Ｓ
各成分の分光特性を測定したところ、Ｐ成分について
は、第３図の特性を比較して1:1からのずれはやや広が
るものの、700〜850nmの波長範囲においてほとんど一定
の分光特性が得られた。Ｓ成分については、第１の実施
例とほぼ同様の良好な特性が得られた。Also in this embodiment, θ = 45 from the incident side medium (air) 5
When the incident light is incident at an incident angle of °, P ・ S
When the spectral characteristics of each component were measured, the characteristics of P component were compared and the deviation from 1: 1 spreads slightly, but almost constant spectral characteristics were obtained in the wavelength range of 700 to 850 nm. It was With regard to the S component, almost the same good characteristics as in the first embodiment were obtained.
さらに、第２層のSi膜32として屈折率nH＝3.9のSi膜を
使用した場合には、第１の実施例の第３図に示した特性
とほぼ同等の特性が得られる。Further, when a Si film having a refractive index n H = 3.9 is used as the second layer Si film 32, the characteristics substantially the same as the characteristics shown in FIG. 3 of the first embodiment are obtained.
（実施例４） 第７図は本実施例の第４の実施例を示す断面図である。
本実施例の無偏光ビームスプリツター1Dは、第３の実施
例の多層膜3Cの第２層と第４層とを入れ換えた構造を有
する。すなわち本実施例の多層膜3Dは、第１層および第
３層のAl2O3膜31（屈折率nL＝1.61）、第２層のTiO2膜3
3（屈折率nM＝2.24）ならびに第４層のSi膜32（屈折率n
H＝3.67）の４層構造を有する。光学的膜厚はλ０/4＝2
10nm、成膜条件も第３の実施例と全く同様である。(Embodiment 4) FIG. 7 is a sectional view showing a fourth embodiment of this embodiment.
The non-polarized beam splitter 1D of this embodiment has a structure in which the second layer and the fourth layer of the multilayer film 3C of the third embodiment are replaced. That is, the multilayer film 3D of the present embodiment is composed of the first and third layers of Al 2 O 3 film 31 (refractive index n L = 1.61) and the second layer of TiO 2 film 3.
3 (refractive index n M = 2.24) and the fourth Si film 32 (refractive index n M = 2.24)
It has a four-layer structure of H = 3.67). Optical thickness is λ 0/4 = 2
The film forming condition is 10 nm, and the film forming conditions are exactly the same as in the third embodiment.
前述したと同様に分光特性を測定したところ、実施例２
のＰ成分に比較すれば、透過率と反射率との分離がやや
大きいものの、良好な結果が得られた。When the spectral characteristics were measured in the same manner as described above, Example 2
Compared to the P component of, the separation between the transmittance and the reflectance was slightly large, but good results were obtained.
なお、多層膜を構成する各膜は、上述した物質に限定さ
れるものではなく、例えばTiO2膜の代りにZrO2膜、Al2O
3膜の代りにCeF3膜を用いても、それぞれ屈折率がほぼ
同等であることから、上述した各実施例とほぼ同様の特
性の無偏光ビームスプリツターが得られる。It should be noted that each film forming the multilayer film is not limited to the above-mentioned substances, and for example, instead of the TiO 2 film, a ZrO 2 film, an Al 2 O film is used.
Even if the CeF 3 film is used instead of the 3 films, the non-polarized beam splitters having substantially the same characteristics as those in the above-described respective examples can be obtained because the refractive indexes are substantially the same.
さらに、上述した各実施例は、コンパクト・デイスク装
置において利用される波長帯700〜850nm、入射角45°の
場合を対象としたが、膜を構成する物質、膜の層数、製
造方法および条件等を変えることにより、他の波長域、
入射角にも対応できる。あお、光学的膜厚ndは設計中心
波長λ０に対してλ０/4とすることが基本であるが、±
20％程度のずれは許容可能である。また、各膜の屈折率
は、例えば平板状透明基板２の屈折率ngを1.3＜ng＜4.0
とした場合、それぞれ3.0＜nH＜6.0、2.0＜nM＜4.0、1.
3＜nL＜2.3程度の範囲内で設定することが望ましい。具
体的には前述した各物質の他、Ge,SiO2，La2O3,SiO,MgF
2,ZnS,Ce2O3，In2O3，CeO2，Cr2O3，Fe2O3，Na3AlF6，P
bCl2,PbTe,Te,Y2O3,ZnSe,LaF3などを組合せて用いるこ
とができる。Furthermore, each of the above-described examples is directed to the case where the wavelength band used in the compact disc device is 700 to 850 nm and the incident angle is 45 °, the substance constituting the film, the number of layers of the film, the manufacturing method and conditions. By changing the other wavelength range,
It can also handle incident angles. Blue, although optical thickness n d is fundamental that a lambda 0/4 with respect to the designed center wavelength lambda 0, ±
A shift of about 20% is acceptable. Further, the refractive index of each film is, for example, 1.3 <n g <4.0 with respect to the refractive index ng of the flat transparent substrate 2.
, 3.0 <n H <6.0, 2.0 <n M <4.0, 1.
It is desirable to set within the range of 3 <n L <2.3. Specifically, in addition to the above substances, Ge, SiO 2 , La 2 O 3 , SiO, MgF
2 , ZnS, Ce 2 O 3 , In 2 O 3 , CeO 2 , Cr 2 O 3 , Fe 2 O 3 , Na 3 AlF 6 , P
bCl 2 , PbTe, Te, Y 2 O 3 , ZnSe, LaF 3 etc. can be used in combination.
なお、平板状透明基板２は、対象とする波長帯内の光を
透過させるものでなければならないが、その限りにおい
て、多層膜の形成が可能まものであればよく、BK−７ガ
ラス以外の光学ガラスやホワイト・クラウン・ガラス，
ソーダ・ライム・ガラス，あるいは各種色ガラス、テン
パツクス（商品名）等の耐熱ガラス、さらにはプラスチ
ツクなどの使用が可能である。It should be noted that the flat transparent substrate 2 must be one that transmits light in the target wavelength band, but as long as it is capable of forming a multilayer film, it is not limited to BK-7 glass. Optical glass and white crown glass,
It is possible to use soda lime glass, various colored glasses, heat-resistant glass such as Tempax (trade name), and plastic.
以上説明した通り、本発明によれば、相互に異なる屈折
率nL，nM，nH（nL＜nM＜nH）を有する３種の膜を、基板
から遠い側から奇数層目が屈折率nLの膜、偶数層目が屈
折率nMまたはnHの膜となるように多層に積層し、かつ屈
折率ng,nL,nM,nHを、それぞれ1.3＜ng＜4.0、1.3＜nL＜
2.3、2.0＜nM＜4.0および3.0＜nH＜6.0の範囲に設定し
たことにより、実在する物質の組合せにより、Ｐ成分と
Ｓ成分のそれぞれの透過率と反射率との比が広い波長範
囲でほぼ1:1となる無偏光ビームスプリツターが得られ
る。As described above, according to the present invention, three kinds of films having different refractive indexes n L , n M , and n H (n L <n M <n H ) are provided in the odd layer from the side far from the substrate. Is a film with a refractive index n L , and the even layers are films with a refractive index n M or n H , and the refractive indices ng, nL, nM, and nH are 1.3 <ng <4.0, 1.3, respectively. <NL <
By setting the range of 2.3, 2.0 <nM <4.0, and 3.0 <nH <6.0, the ratio of the transmittance and reflectance of each of the P component and the S component is almost constant over a wide wavelength range due to the combination of existing substances. A 1: 1 unpolarized beam splitter is obtained.
第１図ないし第３図は本発明の一実施例を示す図で、第
２図は無偏光ビームスプリツターの側面図、第１図はそ
の多層膜の構成を示す断面図、第３図は分光特性を示す
図、第４図は本発明の他の実施例を示す断面図、第５図
はその分光特性を示す図、第６図および第７図はそれぞ
れ本発明の実施例を示す断面図である。 1A〜1D……無偏光ビームスプリツター、２……平板状透
明基板、3A〜3D……多層膜、31……屈折率nLのAl2O
3膜、32……屈折率nHのSi膜、33……屈折率nMのTiO
2膜。1 to 3 are views showing an embodiment of the present invention, FIG. 2 is a side view of a non-polarizing beam splitter, FIG. 1 is a sectional view showing the structure of its multilayer film, and FIG. FIG. 4 is a sectional view showing a spectral characteristic, FIG. 4 is a sectional view showing another embodiment of the present invention, FIG. 5 is a diagram showing its spectral characteristic, and FIGS. 6 and 7 are sectional views showing an embodiment of the present invention. It is a figure. 1A ~ 1D ... unpolarized beam splitter, 2 ... flat plate transparent substrate, 3A ~ 3D ... multilayer film, 31 ... Al 2 O with refractive index n L
3 film, 32 ... Si film with refractive index n H , 33 ... TiO with refractive index n M
2 membranes.
Claims (1)
相互に異なる屈折率nL,nM,nH（nL＜nM＜nH）を有する３
種の膜を、平面状透明基板から最も遠い側から奇数番目
が屈折率nLの膜、偶数番目が屈折率nMの膜または屈折率
nHの膜となるように多層に積層し、前記屈折率ng,nL,n
M,nHは、それぞれ1.3＜ng＜4.0、1.3＜nL＜2.3、2.0＜n
M＜4.0および3.0＜nH＜6.0の範囲に設定されていること
を特徴とする無偏光ビームスプリッター。1. A main surface of a flat transparent substrate having a refractive index of ng,
3 having different refractive indices nL, nM, nH (nL <nM <nH)
From the side farthest from the planar transparent substrate, the seed film is a film with an index of refraction nL at the odd number and a film with a refractive index of nM at the even number.
Layered in multiple layers to form a film of nH, the refractive index ng, nL, n
M and nH are 1.3 <ng <4.0, 1.3 <nL <2.3, 2.0 <n, respectively.
A non-polarizing beam splitter characterized by being set in the range of M <4.0 and 3.0 <nH <6.0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61153065A JPH0738041B2 (en) | 1986-06-30 | 1986-06-30 | Non-polarized beam splitter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61153065A JPH0738041B2 (en) | 1986-06-30 | 1986-06-30 | Non-polarized beam splitter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS638702A JPS638702A (en) | 1988-01-14 |
| JPH0738041B2 true JPH0738041B2 (en) | 1995-04-26 |
Family
ID=15554214
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61153065A Expired - Lifetime JPH0738041B2 (en) | 1986-06-30 | 1986-06-30 | Non-polarized beam splitter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0738041B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994000782A1 (en) * | 1992-06-19 | 1994-01-06 | Fujitsu Limited | Photocoupler |
| JP2007133375A (en) * | 2005-10-11 | 2007-05-31 | Konica Minolta Opto Inc | Non-polarizing beam splitter |
| WO2011048875A1 (en) | 2009-10-20 | 2011-04-28 | シグマ光機株式会社 | Plate-type broadband depolarizing beam splitter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6155602A (en) * | 1984-08-27 | 1986-03-20 | Canon Inc | Beam splitter |
-
1986
- 1986-06-30 JP JP61153065A patent/JPH0738041B2/en not_active Expired - Lifetime
Non-Patent Citations (1)
| Title |
|---|
| Ｏｐｔ，Ａｃｔａ，Ｖｏｌ．８（１９６１） |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS638702A (en) | 1988-01-14 |
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