JPH0548191A - Solid-state laser rod - Google Patents
Solid-state laser rodInfo
- Publication number
- JPH0548191A JPH0548191A JP22978991A JP22978991A JPH0548191A JP H0548191 A JPH0548191 A JP H0548191A JP 22978991 A JP22978991 A JP 22978991A JP 22978991 A JP22978991 A JP 22978991A JP H0548191 A JPH0548191 A JP H0548191A
- Authority
- JP
- Japan
- Prior art keywords
- laser
- rod
- yag
- laser rod
- solid
- 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.)
- Withdrawn
Links
- 239000000843 powder Substances 0.000 claims abstract description 11
- 229910000420 cerium oxide Inorganic materials 0.000 claims abstract description 4
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 3
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims abstract description 3
- 230000000694 effects Effects 0.000 abstract description 12
- 230000005284 excitation Effects 0.000 abstract description 10
- 238000010276 construction Methods 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 17
- 238000004040 coloring Methods 0.000 description 13
- 230000010355 oscillation Effects 0.000 description 7
- 239000013078 crystal Substances 0.000 description 6
- 238000010521 absorption reaction Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 230000031700 light absorption Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- -1 iron ion Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
Landscapes
- Lasers (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は固体レーザ装置に用いら
れる固体レーザロッドに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state laser rod used in a solid-state laser device.
【0002】[0002]
【従来の技術】一般に、この種の固体レーザロッドとし
て、Nd:YAG単結晶からなる固体レーザロッド(以
下Nd:YAGレーザロッドという)が知られている。
このNd:YAGレーザロッドでは紫外線によって着色
が発生し、着色されたレーザロッドを励起した際には、
着色量に比例した熱レンズ効果が生じる。そして、この
熱レンズ効果によってレーザ装置の共振器中にあたかも
レンズが配置された状態となり、励起エネルギーが共振
器の安定領域から外れて、その結果、レーザ出力が低下
する。2. Description of the Related Art Generally, as this type of solid-state laser rod, a solid-state laser rod made of Nd: YAG single crystal (hereinafter referred to as Nd: YAG laser rod) is known.
In this Nd: YAG laser rod, coloring is generated by ultraviolet rays, and when the colored laser rod is excited,
A thermal lens effect occurs in proportion to the amount of coloring. Then, due to this thermal lens effect, the lens is placed in the resonator of the laser device as if it were, and the excitation energy deviates from the stable region of the resonator, resulting in a decrease in the laser output.
【0003】ここで、図5及び図6を参照して、Nd:
YAGレーザロッド乃至を準備する。これらNd:
YAGレーザロッド乃至はこの順に着色量が多いも
のとする(図6参照)。図5に示すように、着色量の多
いNd:YAGレーザロッドでは前述のように熱レン
ズ効果が大きく、このため、励起エネルギーが比較的低
いところで、共振器の安定領域から外れ、その結果、レ
ーザ装置の出力が低下する。ここで、励起エネルギーを
増加していくと、前回とは異なる横モードで共振器の安
定条件が成り立ち、再度レーザ出力が回復増大する。Here, referring to FIGS. 5 and 6, Nd:
Prepare a YAG laser rod or the like. These Nd:
It is assumed that the YAG laser rod or the coloring amount increases in this order (see FIG. 6). As shown in FIG. 5, in the Nd: YAG laser rod with a large amount of coloring, the thermal lens effect is large as described above. Therefore, at a relatively low excitation energy, the laser beam deviates from the stable region of the resonator, and as a result, the laser The output of the device is reduced. Here, as the excitation energy is increased, a stable condition of the resonator is established in a transverse mode different from the previous one, and the laser output is recovered and increased again.
【0004】[0004]
【発明が解決しようとする課題】図5から明らかなよう
に、着色量に比例して、つまり、Nd:YAGレーザロ
ッド乃至の順にレーザ出力の低下する変曲点が低励
起エネルギー側にシフトしている。従って、図5から熱
レンズ効果は着色量に比例することがわかる。このよう
に、従来のNd:YAGレーザロッドでは着色によって
励起エネルギーが共振器の安定領域から外れて、その結
果、レーザ出力が低下するという問題点がある。さら
に、着色量に比例して発熱量が増加し、熱の発散が悪く
なる。従って、熱によってレーザビームの真円度が低下
するばかりでなく、ビーム拡がり角度が大きくなってし
まうという問題点がある。本発明の目的は熱レンズ効果
を抑制して安定したレーザ出力を得ることのできる固体
レーザロッドを提供することにある。As is apparent from FIG. 5, the inflection point at which the laser output decreases in proportion to the amount of coloring, that is, the Nd: YAG laser rod or the order of shifting the laser output to the low excitation energy side. ing. Therefore, it can be seen from FIG. 5 that the thermal lens effect is proportional to the amount of coloring. As described above, in the conventional Nd: YAG laser rod, there is a problem that the excitation energy deviates from the stable region of the resonator due to coloring, and as a result, the laser output decreases. In addition, the amount of heat generated increases in proportion to the amount of coloring, and heat dissipation becomes worse. Therefore, there is a problem that not only the roundness of the laser beam is lowered by heat but also the beam divergence angle is increased. An object of the present invention is to provide a solid-state laser rod capable of suppressing the thermal lens effect and obtaining a stable laser output.
【0005】[0005]
【課題を解決するための手段】本発明によれば、所定の
方向に延びる固体レーザロッド素子を有し、該固体レー
ザロッド素子において前記所定方向に延びる面(側面)
が酸化セリウム(CeO2)層とセリウムを含むCe:
YAP(YAlO3)粉末層とで被覆されていることを
特徴とする固体レーザロッドが得られる。According to the present invention, there is provided a solid-state laser rod element extending in a predetermined direction, and a surface (side surface) of the solid-state laser rod element extending in the predetermined direction.
Is a cerium oxide (CeO 2 ) layer and Ce containing cerium:
A solid-state laser rod characterized by being coated with a YAP (YAlO 3 ) powder layer is obtained.
【0006】[0006]
【作用】YAG結晶内に含まれるNdイオンは1000nm
から200 nmまでの波長領域においてとびとびに鋭い吸
収ピークを有している。上記の波長領域のうちで実際に
レーザ発振に寄与するのは370 nmから900 nmまでの
波長領域における吸収である。一方、YAGレーザ発振
において損失となる着色は、主に400 nmより短い波長
領域で幅広い吸収を示し、この波長領域において吸収さ
れたエネルギーが主に非輻射遷移によって熱に変換す
る。このため、ロッド内部の温度が上昇して冷却水等に
よって冷却されているロッド外周部とロッド中心部とに
温度勾配が生じ、Nd:YAGレーザロッドが見かけ上
凸レンズ状となる。従って、共振器内の回折損失が大き
くなってレーザ出力が低下する。さらに、熱レンズ効果
が大きくなると、励起エネルギーが共振器の安定条件か
らはずれ、当該横モードでの発振が成り立たなくなって
しまう。そして、他の横モードで再びレーザ発振し、レ
ーザ出力が増加する現象が生じる。[Function] Nd ion contained in YAG crystal is 1000 nm
It has abruptly sharp absorption peaks in the wavelength range from to 200 nm. Of the above wavelength range, absorption in the wavelength range from 370 nm to 900 nm actually contributes to laser oscillation. On the other hand, coloring that causes a loss in YAG laser oscillation exhibits a wide absorption mainly in a wavelength region shorter than 400 nm, and the energy absorbed in this wavelength region is mainly converted into heat by non-radiative transition. For this reason, the temperature inside the rod rises and a temperature gradient is generated between the rod outer peripheral portion and the rod central portion which are cooled by the cooling water or the like, and the Nd: YAG laser rod has an apparently convex lens shape. Therefore, the diffraction loss in the resonator increases and the laser output decreases. Further, when the thermal lens effect is increased, the excitation energy deviates from the resonator stability condition, and oscillation in the transverse mode is not established. Then, the laser is oscillated again in another transverse mode, and a phenomenon occurs in which the laser output increases.
【0007】ところで、Nd:YAGレーザロッドにお
ける着色は、結晶中に取り込まれた不純物と酸素欠陥に
よって生じる。例えば、鉄イオン(Fe2+)のような
遷移金属がYAG結晶中に混入すると、電気的中性を保
つべく電子放出したFe3+と電子を捕捉した酸素欠陥
の発生によって着色が発生する。このような着色を防止
するためには、99.9999 %以上の高純度が必要である
が、現状では、アルミナ、イリジウム(Ir)るつぼ、
耐火材等の高純度化が困難であるため、高純度のロッド
を得ることは困難である。By the way, coloring in the Nd: YAG laser rod is caused by impurities and oxygen defects taken in the crystal. For example, when a transition metal such as iron ion (Fe 2+ ) is mixed in the YAG crystal, coloring occurs due to the generation of Fe 3+ that emitted electrons and the oxygen defect that traps the electrons in order to maintain electrical neutrality. In order to prevent such coloring, high purity of 99.9999% or more is required, but at present, alumina, iridium (Ir) crucible,
It is difficult to obtain a high-purity rod because it is difficult to make the refractory material highly purified.
【0008】本発明ではNd:YAGレーザロッドの側
面にCeO2層とCe:YAP粉末層を被覆しており、
Ce:YAP粉末層及びCeO2層はともに350 nm以
下の波長領域において幅広くエネルギーを吸収する。こ
のため、着色によって発生する最も有害な光、つまり、
350 nmより短い光をCe:YAP粉末層及びCeO2
層によって吸収することができる。従って、有害な光が
YAGロッドに入射し、非輻射遷移によって熱に変換さ
れることがなくなり、YAGロッド内部における発熱が
抑制されて熱レンズ効果を小さくすることができる。In the present invention, the side surface of the Nd: YAG laser rod is coated with a CeO 2 layer and a Ce: YAP powder layer,
Both the Ce: YAP powder layer and the CeO 2 layer absorb energy widely in the wavelength region of 350 nm or less. For this reason, the most harmful light produced by coloring is:
Light shorter than 350 nm is irradiated with Ce: YAP powder layer and CeO 2
Can be absorbed by layers. Therefore, harmful light does not enter the YAG rod and is not converted into heat by the non-radiative transition, heat generation inside the YAG rod is suppressed, and the thermal lens effect can be reduced.
【0009】[0009]
【実施例】以下本発明について実施例によって説明す
る。図1を参照して、Nd:YAGレーザロッド1はレ
ーザ媒質部であるロッド本体2を備えており、ロッド本
体2の外周面(側面)にはCeO2層3とCe:YAP
(YAlO3)粉末層4とが順次形成されて側面を被覆
している。EXAMPLES The present invention will be described below with reference to examples. Referring to FIG. 1, an Nd: YAG laser rod 1 includes a rod body 2 that is a laser medium portion, and a CeO 2 layer 3 and Ce: YAP are provided on an outer peripheral surface (side surface) of the rod body 2.
A (YAlO 3 ) powder layer 4 is sequentially formed to cover the side surface.
【0010】上記のロッド本体2を製造する際には、N
dイオンを添加(ドープ)したNd:YAG単結晶から
なるYAG原石を超音波ロータリー加工機を用いて所定
の寸法に打ち抜いて、ロッド原体を得る。そして、この
ロッド原体の両端面を鏡面加工してロッド本体2を得
る。When manufacturing the rod body 2 described above, N
A YAG rough stone made of Nd: YAG single crystal doped with d ions is punched into a predetermined size by using an ultrasonic rotary working machine to obtain a rod raw material. Then, the rod body 2 is obtained by mirror-finishing both end faces of this rod raw material.
【0011】次に、ロッド本体2をCeO2粉末中に埋
め込み、水素雰囲気中において温度1200℃で12時間アニ
ール処理してロッド本体2の側面にCeO2層3を付着
形成する。さらに、このロッド本体2をCe:YAG粉
末に埋め込み、水素雰囲気中において温度1200℃で12時
間アニール処理した。そして、CeO2層3上にCe:
YAG粉末層4を形成した。Next, the rod body 2 is embedded in CeO 2 powder, and annealed in a hydrogen atmosphere at a temperature of 1200 ° C. for 12 hours to deposit a CeO 2 layer 3 on the side surface of the rod body 2. Further, this rod body 2 was embedded in Ce: YAG powder and annealed at 1200 ° C. for 12 hours in a hydrogen atmosphere. Then, on the CeO 2 layer 3, Ce:
The YAG powder layer 4 was formed.
【0012】図2を参照して、上述したNd:YAGレ
ーザロッド1を用いてCWレーザ発振器を構成してレー
ザ発振の評価を行った。この際、比較のため、従来のN
d:YAGレーザロッドを用いて同様にCWレーザ発振
器を構成してレーザ発振の評価を行った(以下本発明に
よるNd:YAGレーザロッドに参照符号(a)を付
し、従来のNd:YAGレーザロッドに参照符号(b)
を付す)。なお、図2において、5は集光器、6は励起
ランプ、7は全反射ミラー、8は出射ミラーである。With reference to FIG. 2, a CW laser oscillator was constructed using the Nd: YAG laser rod 1 described above, and laser oscillation was evaluated. At this time, for comparison, the conventional N
A CW laser oscillator was similarly constructed by using a d: YAG laser rod, and laser oscillation was evaluated (hereinafter, reference numeral (a) is attached to the Nd: YAG laser rod according to the present invention, and a conventional Nd: YAG laser is used. Reference numeral (b) to the rod
Attached). In FIG. 2, 5 is a condenser, 6 is an excitation lamp, 7 is a total reflection mirror, and 8 is an emission mirror.
【0013】図3に示すように、Nd:YAGレーザロ
ッド(b)では熱レンズ効果によってシングルモードレ
ーザ出力が低くなり、一方、Nd:YAGレーザロッド
(a)ではシングルモードレーザ出力が改善されること
が確認できた。なお、図4に示すように、Nd:YAG
レーザロッド(a)で被覆層によってレーザ発振に有害
な350 nm以下の光を効率よく遮断できることがわかる
(図4において、符号(c)、つまり、実線は被覆層の
吸収特性を示し、符号(d)、つまり、破線はYAG結
晶の吸収特性を示す)。As shown in FIG. 3, the Nd: YAG laser rod (b) has a low single mode laser output due to the thermal lens effect, while the Nd: YAG laser rod (a) has an improved single mode laser output. I was able to confirm that. As shown in FIG. 4, Nd: YAG
It can be seen that the laser rod (a) can efficiently block light of 350 nm or less, which is harmful to laser oscillation, by the coating layer (in FIG. 4, symbol (c), that is, the solid line indicates the absorption characteristics of the coating layer, d), that is, the broken line shows the absorption characteristics of the YAG crystal).
【0014】[0014]
【発明の効果】以上説明したように本発明では、ロッド
本体の側面にCeO2層及びCe:YAG粉末層を形成
したから、YAGレーザにとって有害な励起光を遮断し
てロッドの熱レンズ効果を低減にすることができる。そ
の結果、レーザ出力の低下を防止できるという効果があ
る。As described above, in the present invention, since the CeO 2 layer and the Ce: YAG powder layer are formed on the side surface of the rod body, the excitation light harmful to the YAG laser is blocked and the thermal lens effect of the rod is obtained. It can be reduced. As a result, there is an effect that the reduction of the laser output can be prevented.
【図1】本発明によるNd:YAGレーザロッドの一実
施例を示す断面図である。FIG. 1 is a sectional view showing an embodiment of an Nd: YAG laser rod according to the present invention.
【図2】CWレーザ発振器の構成を示す図である。FIG. 2 is a diagram showing a configuration of a CW laser oscillator.
【図3】CWレーザ発振の評価結果を示す図である。FIG. 3 is a diagram showing an evaluation result of CW laser oscillation.
【図4】図1に示すレーザロッドの光吸収特性を示す図
である。FIG. 4 is a diagram showing light absorption characteristics of the laser rod shown in FIG.
【図5】着色が生じたYAGレーザロッドの入出力特性
を示す図である。FIG. 5 is a diagram showing input / output characteristics of a YAG laser rod that is colored.
【図6】着色が生じたYAGレーザロッドにおいてNd
イオン以外による光吸収特性を示す図である。FIG. 6 shows Nd in a colored YAG laser rod.
It is a figure which shows the light absorption characteristic by things other than an ion.
1 Nd:YAGレーザロッド 2 ロッド本体 3 CeO2層 4 Ce:YAP層 5 集光器 6 励起ランプ 7 全反射ミラー 8 出射ミラー1 Nd: YAG laser rod 2 Rod body 3 CeO 2 layer 4 Ce: YAP layer 5 Concentrator 6 Excitation lamp 7 Total reflection mirror 8 Emission mirror
Claims (1)
子を有し、該固体レーザロッド素子において前記所定方
向に延びる面が酸化セリウム(CeO2)層とセリウム
を含むCe:YAP(YAlO3)粉末層とで被覆され
ていることを特徴とする固体レーザロッド。1. A Ce: YAP (YAlO 3 ) powder having a solid-state laser rod element extending in a predetermined direction, and a surface of the solid-state laser rod element extending in the predetermined direction containing a cerium oxide (CeO 2 ) layer and cerium. A solid-state laser rod characterized by being coated with a layer.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22978991A JPH0548191A (en) | 1991-08-16 | 1991-08-16 | Solid-state laser rod |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22978991A JPH0548191A (en) | 1991-08-16 | 1991-08-16 | Solid-state laser rod |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0548191A true JPH0548191A (en) | 1993-02-26 |
Family
ID=16897702
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP22978991A Withdrawn JPH0548191A (en) | 1991-08-16 | 1991-08-16 | Solid-state laser rod |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0548191A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7046712B2 (en) | 2003-05-02 | 2006-05-16 | Jds Uniphase Corporation | Laser resistant to internal ir-induced damage |
KR20180132987A (en) * | 2014-12-05 | 2018-12-12 | 데쿠세리아루즈 가부시키가이샤 | Heating base plate, protection element and electronic equipment |
-
1991
- 1991-08-16 JP JP22978991A patent/JPH0548191A/en not_active Withdrawn
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7046712B2 (en) | 2003-05-02 | 2006-05-16 | Jds Uniphase Corporation | Laser resistant to internal ir-induced damage |
KR20180132987A (en) * | 2014-12-05 | 2018-12-12 | 데쿠세리아루즈 가부시키가이샤 | Heating base plate, protection element and electronic equipment |
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