JPH02234114A - Laser beam attenuator - Google Patents
Laser beam attenuatorInfo
- Publication number
- JPH02234114A JPH02234114A JP5363289A JP5363289A JPH02234114A JP H02234114 A JPH02234114 A JP H02234114A JP 5363289 A JP5363289 A JP 5363289A JP 5363289 A JP5363289 A JP 5363289A JP H02234114 A JPH02234114 A JP H02234114A
- Authority
- JP
- Japan
- Prior art keywords
- laser beam
- beams
- polarizing element
- laser
- attenuator
- 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.)
- Granted
Links
- 230000010287 polarization Effects 0.000 claims abstract description 8
- 230000002238 attenuated effect Effects 0.000 claims abstract description 6
- 238000010521 absorption reaction Methods 0.000 claims description 10
- 230000003287 optical effect Effects 0.000 abstract description 12
- 239000006096 absorbing agent Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Landscapes
- Lasers (AREA)
- Mechanical Light Control Or Optical Switches (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は，高出力レーザビームを利用したレーザ加工機
等において，連続的ノＰワー制御に用いるレーザビーム
減衰器Ｋ関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser beam attenuator K used for continuous power control in a laser processing machine using a high-power laser beam.
従来のレーデビーム用減衰器には，光吸収形のフィルタ
，誘電体多層膜を用いた部分反射鏡，アルミニウムや銀
等の金属を薄く蒸着した部分反射鏡が用いられている。Conventional Lede beam attenuators use light-absorbing filters, partial reflecting mirrors using a dielectric multilayer film, and partial reflecting mirrors on which a metal such as aluminum or silver is thinly deposited.
上述した従来のレーデビーム減衰器は，金属蒸着膜の厚
さに匂配をつけたものを除いて，それらの光減衰率は離
散的であシ，任意の減衰量を得るのは不可能である。ま
た，吸収形フィルタの場合は，レーデパワーを吸収して
フィルタ自体が発熱し局部的に膨張するため，レーザビ
ームの広がり角やノ母ワー分布に変化を与えてしまうだ
けでなく，レーデパワーが大きくなるとフィルタ自身が
溶融したシ，破壊して使用できなくなる。In the conventional Lede beam attenuators mentioned above, their optical attenuation rates are discrete, and it is impossible to obtain an arbitrary amount of attenuation, except for those that vary depending on the thickness of the metal evaporated film. . In addition, in the case of absorption filters, the filter itself generates heat and expands locally by absorbing the Rade power, which not only changes the spread angle of the laser beam and the power distribution, but also increases the Rade power. The filter itself may melt and be destroyed, making it unusable.
金属蒸着膜による光減衰器についても，ビーム径が小さ
くレーザ／ｌワーが微小な場合については連続的に減衰
量が変化できるが，金属材料そのものの光に対する僅か
な吸収損は避けようがなく，レーザ・２ワーの増大と共
に膜の焼損を生じ，使用不可能となる。For optical attenuators using metal vapor deposited films, the amount of attenuation can be changed continuously when the beam diameter is small and the laser/l power is minute, but a slight absorption loss of the light in the metal material itself cannot be avoided. As the laser power increases, the film burns out and becomes unusable.
本発明は従来のもののこのような課題を解決しようとす
るもので，レーザビームの吸収は殆どなく，レーザ／Ｊ
？ワーによる減衰器自身の熱的変形，歪，破壊のないレ
ーザビーム減衰器を提供するものである。The present invention is an attempt to solve these problems of the conventional ones, and there is almost no absorption of the laser beam, and the laser/J
? The object of the present invention is to provide a laser beam attenuator that is free from thermal deformation, distortion, and destruction of the attenuator itself due to warping.
上述した従来のレーザビーム減衰器に対し，本発明は，
レーザビームの偏光を２成分に分け，直線偏光状態で夫
々連続的に減衰量を制御し，その後１本のビームに合成
するようにしたものである。In contrast to the conventional laser beam attenuator described above, the present invention has the following features:
The polarization of the laser beam is divided into two components, the attenuation of each component is continuously controlled in a linearly polarized state, and then the components are combined into one beam.
すなわち本発明によれば，入射レーデビームを偏光成分
の異なる２本のビームに分割する，誘電体多層膜からな
る分割用偏光素子と，該分割され減衰された・ヤワーを
持つレーザビームを透過すると共に，前記減衰に相当す
る残余のパワーを持つ不要のレーザピームを反射する．
誘電体多層膜からなる２つの回転偏光素子と，前記反射
した不要のレーザビームを吸収する第１の吸収手段と，
前記２つの回転偏光素子からの透過ビームを合成して，
所望の出射ビームおよびこの合成に伴う不要のレーデビ
ームを発する，誘電体多層膜からなる合成用偏光素子と
，前記合成に伴う不要のレーデビームを吸収する第２の
吸収手段とを含むことを特徴とするレーデビーム減衰器
が得られる。That is, according to the present invention, there is provided a splitting polarizing element made of a dielectric multilayer film that splits an incident LED beam into two beams with different polarization components, and a splitting polarizing element that splits an incident LED beam into two beams with different polarization components; , reflects the unnecessary laser beam with a residual power corresponding to the attenuation.
two rotating polarizing elements made of dielectric multilayer films; a first absorption means for absorbing the reflected unnecessary laser beam;
Combining the transmitted beams from the two rotating polarizing elements,
It is characterized by comprising a combining polarizing element made of a dielectric multilayer film that emits a desired output beam and an unnecessary Radeh beam accompanying the combining, and a second absorption means for absorbing the unnecessary Radeh beam accompanying the combining. A Lede beam attenuator is obtained.
上記の構成において，回転偏光素子の回転角度を調整す
れば，所望の任意の値の減衰率を有する出射ビームを得
ることができる。In the above configuration, by adjusting the rotation angle of the rotating polarizing element, an output beam having an attenuation factor of any desired value can be obtained.
次Ｋ本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明の第１の実施例の構成図である。FIG. 1 is a block diagram of a first embodiment of the present invention.
２，３，５，６，８．９．１０はすべて誘電体多層膜に
よって形成される偏光素子で，任意の偏光ビームをある
一定入射角で入射させると，入射面に平行な偏光（Ｐ偏
光）成分のビームは透過し，入射面に垂直な偏光（Ｓ偏
光）成分ビームは反射する。2, 3, 5, 6, 8, 9, and 10 are all polarizing elements formed by dielectric multilayer films, and when an arbitrary polarized beam is incident at a certain angle of incidence, it becomes polarized light parallel to the incident plane (P ) component beams are transmitted, and polarized (S-polarized) component beams perpendicular to the plane of incidence are reflected.
反射鏡７は偏光素子２と同じ誘電体多層膜偏光素子，ま
たは全反射鏡よシなる。The reflecting mirror 7 is the same dielectric multilayer polarizing element as the polarizing element 2, or a total reflection mirror.
入射ピーム１はまず分割用偏光素子２に偏光素子によク
て定まる入射角で入射すると．Ｐ偏光成分は損失なく透
過し，回転偏光素子３に到達する。The incident beam 1 first enters the splitting polarizing element 2 at an incident angle determined by the polarizing element. The P-polarized light component is transmitted without loss and reaches the rotating polarizing element 3.
一方，Ｓ偏光成分は反射鏡７へ向う。回転偏光素子３が
分割用偏光素子２に平行な基準位置から光路を軸として
角度θだけ回転していると，回転偏光素子３を透過する
光の電界は邸θ倍となる。すなわち透過するレーデパワ
−は郎θ倍となる。このことは（ １ − ｃｍ２θ）
倍の減衰を受けることを意味する。回転偏光素子３によ
って反射された（１−ｃａｌ２ｆ） ）倍のレーザパワ
ーは反射方向が偏光素子３の回転と共Ｋ変化するが，偏
光素子３を基準とすると固定しているので，偏光素子３
に対して相対的に固定された吸収体１２によって吸収さ
れる。On the other hand, the S-polarized light component heads toward the reflecting mirror 7. When the rotating polarizing element 3 is rotated by an angle θ about the optical path from a reference position parallel to the dividing polarizing element 2, the electric field of the light transmitted through the rotating polarizing element 3 becomes θ times as large as θ. In other words, the transmitted redepower is multiplied by θ. This means (1 - cm2θ)
This means that it will receive twice as much attenuation. The direction of reflection of the (1-cal2f) times the laser power reflected by the rotating polarizing element 3 changes by K with the rotation of the polarizing element 3, but it is fixed when the polarizing element 3 is used as a reference.
It is absorbed by the absorbent body 12 which is fixed relative to the body.
吸収体はレーザノ４ワーのレベルによって選定する。The absorber is selected depending on the level of laser power.
特にレーザノクワーが数１０ワットから数１００ワット
の高レベル時には，水冷形の吸収体を使用する。In particular, when the laser power is at a high level of several tens to hundreds of watts, a water-cooled absorber is used.
偏光素子５は偏光素子３と左右対称の位置に配置し，偏
光素子の基板の厚みによって生ずる光路のずれを補正す
るもので．ビームの反射は生じない。The polarizing element 5 is placed in a position symmetrical to the polarizing element 3, and is used to correct deviations in the optical path caused by the thickness of the substrate of the polarizing element. No beam reflections occur.
偏光素子５を透過したビームの偏光の向きは，合成用偏
光素子６の入射面に対しては角度θの傾きをもクておシ
，透過／臂ワー（出射ビーム１１の一部となる）はさら
にａｌｌｓ２θ倍となり，反射パワーは（ １ ＝ ｃ
ａｓ２θ）倍となぁ。従クて，入射ビームの内，Ｐ偏光
成分は■θ倍となり，理想的にはθ＝Ｏｃでは減衰量０
チ，θ＝９０°では１００％となる。しかし実際には誘
電体多屓膜偏光素子を透過するＰ偏光成分に対し，数１
００分の１程度Ｓ偏光成分が残ること，および各偏光素
子の若干の散乱，吸収による損失があるため，完全な透
過０チ，透過１００％とはならない。The direction of polarization of the beam transmitted through the polarizing element 5 is determined by the angle θ with respect to the incident plane of the combining polarizing element 6, and the direction of the polarized light is determined by the direction of the beam transmitted through the polarizing element 5. is further multiplied by alls2θ, and the reflected power is (1 = c
as2θ) times. Therefore, the P-polarized component of the incident beam will be multiplied by ■θ, and ideally, at θ=Oc, the attenuation will be 0.
H, it becomes 100% when θ=90°. However, in reality, for the P-polarized light component transmitted through the dielectric multilayer polarizing element,
Since an S-polarized light component of about 1/00 remains and there is some loss due to scattering and absorption of each polarizing element, complete transmission is not 0 or 100%.
また，合成用偏光素子６で反射された（１−（自）２θ
）倍の・ぐワービームは吸収体１４に吸収される。すな
わちこの分だけ更に減衰が働くことになる。In addition, the (1-(auto)2θ) reflected by the polarizing element 6 for synthesis
) is absorbed by the absorber 14. In other words, further attenuation will occur by this amount.
一方，反射鏡７に到達したＳ偏光成分のビームは回転偏
光素子８によって減衰される。この偏光素子８は偏光素
子６と９０°十〇光路を軸として回転した位置で透過率
がｃｌＥ２θとなる。この減衰したレーザビームは偏光
素子１０で反射され，この際レーザ・ぞワーは更に減衰
を受けて邸θとなる。このレーザビームは合成偏光素子
６で全反射され，偏光素子５からの透過ビームと同一光
路に合成されもすなわちＰ偏光成分，Ｓ偏光成分共に郎
４θ倍されて出射ビーム１１となる。なお偏光素子９は
偏光素子５と同様光路のずれを補正するものである。On the other hand, the beam of S-polarized light component reaching the reflecting mirror 7 is attenuated by the rotating polarizing element 8. This polarizing element 8 has a transmittance of clE2θ at a position rotated by 90° with respect to the polarizing element 6 about the optical path. This attenuated laser beam is reflected by the polarizing element 10, and at this time, the laser beam is further attenuated and becomes θ. This laser beam is totally reflected by the combining polarizing element 6 and combined on the same optical path as the transmitted beam from the polarizing element 5, that is, both the P polarized light component and the S polarized light component are multiplied by 4θ to become an output beam 11. Note that the polarizing element 9, like the polarizing element 5, corrects the deviation of the optical path.
第２図，第３図はそれぞれ本発明の第２実施例の平面図
，および斜視図である。偏光素子２１，２２，２３ ．
２４はＰ偏光については光路は入射光の延長方向，Ｓ偏
光については入射光と直角をなすもので，第１実施例の
平板状偏光素子の場合に比べて構成が簡単化できる。し
かし，出力ビーム１ｌの出射方向は第３図に示すように
入射ビーム１に対して９０°方向が変わるので，光軸を
直線状にするには更に数枚の反射鏡を使う必要がある。FIGS. 2 and 3 are a plan view and a perspective view, respectively, of a second embodiment of the present invention. Polarizing elements 21, 22, 23.
24, for P-polarized light, the optical path is in the extending direction of the incident light, and for S-polarized light, it is perpendicular to the incident light, and the configuration can be simplified compared to the flat polarizing element of the first embodiment. However, since the output direction of the output beam 1l changes by 90 degrees with respect to the incident beam 1 as shown in FIG. 3, it is necessary to use several more reflecting mirrors to make the optical axis straight.
光の減衰量については第１の実施例同様，回転偏光素子
２２と２４のそれぞれが，最大透過となる基準位置から
の回転角をθとすれば，入射・９ワーの邸４０倍が透過
し，（ｌｅｎｓ’θ）倍が吸収体２７．２８に吸収され
る。Regarding the amount of attenuation of light, as in the first embodiment, if the rotation angle from the reference position at which each of the rotating polarizing elements 22 and 24 achieves maximum transmission is θ, then 40 times as much light as the incident light is transmitted. , (lens'θ) times is absorbed by the absorber 27.28.
このように本発明によると，任意の光減衰量の得られる
光減衰器を構成できる。また本発明によるレーザビーム
減衰器は，吸収タイプのフィルタを使用していないので
，高出力レーザに適している。特に高出力固体レーザの
出力は一般に無偏光で，２つの偏光成分Ｋ分離するとそ
れぞれはエネルギーの空間分布も異り，出力のふらつき
も太きいが，両方共一定の比率，すなわちμｓ４０倍に
減衰した後合成されるので，全体の安定度としては元の
レーデ発振器の安定度，及び空間分布を保存できる利点
がある。As described above, according to the present invention, it is possible to construct an optical attenuator that can obtain an arbitrary amount of optical attenuation. Furthermore, since the laser beam attenuator according to the present invention does not use an absorption type filter, it is suitable for high-power lasers. In particular, the output of high-power solid-state lasers is generally unpolarized, and when separated into two polarization components, each has a different spatial distribution of energy and a large fluctuation in output, but both are attenuated by a constant ratio, that is, 40 times μs. Since it is post-synthesized, the overall stability has the advantage of preserving the stability and spatial distribution of the original Rade oscillator.
本発明は以上′説明したようにレーザピームの偏光を直
交する２成分に分け，直線偏光状態で夫々連続的に減衰
量を制御し，その後１本のビームに合成するため，レー
ザ出力を連続的に制御し，且つレーザビームの吸収は殆
ど無く，レーデパヮーによる熱的変形，歪，破壊が発生
しない効果がある。As explained above, the present invention divides the polarization of the laser beam into two orthogonal components, continuously controls the attenuation of each component in the linearly polarized state, and then combines the laser beam into one beam, so the laser output is continuously adjusted. In addition, there is almost no absorption of the laser beam, and there is an effect that thermal deformation, distortion, and destruction caused by the laser beam do not occur.
９，１０は偏光素子，１１は出射ビーム，１２，１３，
１４．１５は吸収体である。9, 10 are polarizing elements, 11 is an output beam, 12, 13,
14.15 is an absorber.
第１図は本発明の第１の実施例の平面図，第２図と第３
図は本発明の第２の実施例の平面図と斜視図である。
記号の説明：１は入射ビーム，２は分割用偏光素子，３
は回転偏光素子，５は偏光素子，６は合成用偏光素子，
７は反射鏡，８は回転偏光素子，第２図Figure 1 is a plan view of the first embodiment of the present invention, Figures 2 and 3 are
The figures are a plan view and a perspective view of a second embodiment of the invention. Explanation of symbols: 1 is the incident beam, 2 is the polarizing element for splitting, 3
is a rotating polarizing element, 5 is a polarizing element, 6 is a combining polarizing element,
7 is a reflecting mirror, 8 is a rotating polarizing element, Fig. 2
Claims (1)
ムに分割する、誘電体多層膜からなる分割用偏光素子と
、 該分割された２本のビームの光軸の回りに回転可能に配
置され、該ビームを２つのビームに分け、基準位置から
の回転角度に応じた減衰されたパワーを持つレーザビー
ムを透過させると共に、前記減衰に相当する残余のパワ
ーを持つ不要のレーザビームを反射する、誘電体多層膜
からなる２つの回転偏光素子と、前記反射した不要のレ
ーザビームを吸収する第１の吸収手段と、 前記２つの回転偏光素子からの透過ビームを合成して、
所望の出射ビームおよびこの合成に伴う不要のレーザビ
ームを発する、誘電体多層膜からなる合成用偏光素子と
、 前記合成に伴う不要のレーザビームを吸収する第２の吸
収手段とを含むことを特徴とするレーザビーム減衰器。(1) A splitting polarizing element made of a dielectric multilayer film that splits an incident laser beam into two beams with different polarization components; , dividing the beam into two beams, transmitting the laser beam having attenuated power according to the rotation angle from the reference position, and reflecting the unnecessary laser beam having the remaining power corresponding to the attenuation; two rotating polarizing elements made of a dielectric multilayer film, a first absorption means for absorbing the reflected unnecessary laser beam, and combining the transmitted beams from the two rotating polarizing elements,
A combining polarizing element made of a dielectric multilayer film that emits a desired output beam and an unnecessary laser beam accompanying the combining, and a second absorption means that absorbs the unnecessary laser beam accompanying the combining. Laser beam attenuator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5363289A JPH0792558B2 (en) | 1989-03-08 | 1989-03-08 | Laser beam attenuator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5363289A JPH0792558B2 (en) | 1989-03-08 | 1989-03-08 | Laser beam attenuator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02234114A true JPH02234114A (en) | 1990-09-17 |
| JPH0792558B2 JPH0792558B2 (en) | 1995-10-09 |
Family
ID=12948277
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5363289A Expired - Fee Related JPH0792558B2 (en) | 1989-03-08 | 1989-03-08 | Laser beam attenuator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0792558B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7259914B2 (en) * | 2005-08-30 | 2007-08-21 | Coherent, Inc. | Attenuator for high-power unpolarized laser beams |
| US7706069B2 (en) | 2007-05-14 | 2010-04-27 | Coherent, Inc. | Attenuator for high-power unpolarized laser beams |
| JP2015158631A (en) * | 2014-02-25 | 2015-09-03 | 株式会社リコー | Light amount adjustment device as well as light irradiation device using the same, and image display device |
| CN114441032A (en) * | 2022-01-19 | 2022-05-06 | 西北核技术研究所 | High-energy laser power tracing transfer system and method based on wedge lens group cascade attenuation |
-
1989
- 1989-03-08 JP JP5363289A patent/JPH0792558B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7259914B2 (en) * | 2005-08-30 | 2007-08-21 | Coherent, Inc. | Attenuator for high-power unpolarized laser beams |
| US7327518B2 (en) | 2005-08-30 | 2008-02-05 | Coherent, Inc. | Attenuator for high-power unpolarized laser beams |
| US7706069B2 (en) | 2007-05-14 | 2010-04-27 | Coherent, Inc. | Attenuator for high-power unpolarized laser beams |
| JP2015158631A (en) * | 2014-02-25 | 2015-09-03 | 株式会社リコー | Light amount adjustment device as well as light irradiation device using the same, and image display device |
| CN114441032A (en) * | 2022-01-19 | 2022-05-06 | 西北核技术研究所 | High-energy laser power tracing transfer system and method based on wedge lens group cascade attenuation |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0792558B2 (en) | 1995-10-09 |
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