JP3447078B2 - Optical wavelength conversion element - Google Patents
Optical wavelength conversion elementInfo
- Publication number
- JP3447078B2 JP3447078B2 JP06650893A JP6650893A JP3447078B2 JP 3447078 B2 JP3447078 B2 JP 3447078B2 JP 06650893 A JP06650893 A JP 06650893A JP 6650893 A JP6650893 A JP 6650893A JP 3447078 B2 JP3447078 B2 JP 3447078B2
- Authority
- JP
- Japan
- Prior art keywords
- phase matching
- region
- wavelength conversion
- harmonic
- conversion element
- 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
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、基本波をより短波長の
光に波長変換する光波長変換素子に関し、特に詳細に
は、１素子で２回の波長変換を行なって例えば第４高調
波等の極めて短波長の光を得るようにした光波長変換素
子に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical wavelength conversion device for converting a fundamental wave into light of a shorter wavelength. More specifically, one device performs wavelength conversion twice to, for example, a fourth harmonic wave. The present invention relates to an optical wavelength conversion element adapted to obtain light having an extremely short wavelength such as.
【０００２】[0002]
【従来の技術】従来より、非線形光学材料を利用して、
レーザービームを第２高調波等に波長変換（短波長化）
する試みが種々なされている。このようにして波長変換
を行なう光波長変換素子として具体的には、バルク結晶
型のものや、光導波路型のもの等が知られている。2. Description of the Related Art Conventionally, nonlinear optical materials have been used to
Wavelength conversion of laser beam to second harmonic etc. (shorter wavelength)
Various attempts have been made. As a light wavelength conversion element that performs wavelength conversion in this manner, specifically, a bulk crystal type, an optical waveguide type, and the like are known.
【０００３】上述のようにしてレーザービームを波長変
換する場合、より短波長の光を得るために、基本波を複
数の光波長変換素子に次々と入射させることが考えられ
ている。すなわち、基本波を第１の光波長変換素子に入
射させて第２高調波を発生させ、さらにこの第２高調波
を第２の光波長変換素子に入射させて第２高調波を発生
させれば、結局、元の基本波に対しては波長が１／４の
第４高調波が得られることになる。When wavelength-converting a laser beam as described above, it has been considered that the fundamental wave is successively incident on a plurality of optical wavelength conversion elements in order to obtain light of a shorter wavelength. That is, the fundamental wave is incident on the first optical wavelength conversion element to generate the second harmonic, and the second harmonic is incident on the second optical wavelength conversion element to generate the second harmonic. For example, in the end, the fourth harmonic having a wavelength of ¼ of the original fundamental wave is obtained.
【０００４】[0004]
【発明が解決しようとする課題】しかし、基本波を複数
の光波長変換素子に次々と入射させると、ある光波長変
換素子で波長変換された光が別の光波長変換素子に入射
する際にその端面でフレネル反射し、それにより光損失
が大きくなって、高い波長変換効率を得ることが困難と
なる。However, when the fundamental wave is successively incident on a plurality of optical wavelength conversion elements, when the light whose wavelength is converted by one optical wavelength conversion element is incident on another optical wavelength conversion element. Fresnel reflection occurs at the end face, which causes a large optical loss and makes it difficult to obtain high wavelength conversion efficiency.
【０００５】またレーザー共振器内に複数の光波長変換
素子を挿入する場合は、素子端面における光散乱による
損失も大きくなる。つまり例えばレーザー共振器内に２
個の光波長変換素子を挿入する場合は、１個の光波長変
換素子を挿入する場合と比べて素子端面が２倍の４面と
なり、素子端面の光散乱による損失もほぼ２倍に増大す
る。このような損失の増大も、勿論、波長変換効率の低
下につながるものである。Further, when a plurality of optical wavelength conversion elements are inserted in the laser resonator, the loss due to light scattering at the element end face also becomes large. So, for example, 2 in the laser cavity
In the case of inserting one light wavelength conversion element, the element end face is four times as large as in the case of inserting one light wavelength conversion element, and the loss due to light scattering of the element end face is almost doubled. . Such an increase in loss, of course, also leads to a decrease in wavelength conversion efficiency.
【０００６】さらに、複数の光波長変換素子を用いる場
合は、光通過端面が増えるので、それらの研磨およびコ
ーティング作業も多くなり、そのために、これら複数の
素子からなる光波長変換装置のコストはかなり高くつい
ていた。Further, when a plurality of light wavelength conversion elements are used, the number of light passing end faces increases, so that the polishing and coating work for them also increases, and therefore the cost of the light wavelength conversion device composed of these plurality of elements is considerable. It was expensive.
【０００７】本発明は上記の事情に鑑みてなされたもの
であり、高い波長変換効率の下に極めて短波長の光を得
ることができ、そして比較的安価に形成可能な光波長変
換素子を提供することを目的とするものである。The present invention has been made in view of the above circumstances, and provides an optical wavelength conversion element that can obtain light of an extremely short wavelength with high wavelength conversion efficiency and that can be formed at a relatively low cost. The purpose is to do.
【０００８】[0008]
【課題を解決するための手段】本発明による光波長変換
素子は、１つの非線形光学材料の結晶に、該結晶に入射
した基本波としてのレーザービームを波長変換する第１
の位相整合領域と、この第１の位相整合領域から出射し
た波長変換波をさらに波長変換する第２の位相整合領域
とが形成され、これら２つの位相整合領域の一方が角度
位相整合または温度位相整合を取る領域で、他方が周期
ドメイン反転構造を有して疑似位相整合を取る領域であ
ることを特徴とするものである。An optical wavelength conversion element according to the present invention is a first wavelength conversion device for converting a wavelength of a laser beam as a fundamental wave incident on the crystal into one crystal of a nonlinear optical material.
Phase matching region and a second phase matching region that further converts the wavelength-converted wave emitted from the first phase matching region are formed, and one of these two phase matching regions is either angular phase matching or temperature phase matching. This is a region where matching is performed, and the other is a region where a quasi phase matching is performed by having a periodic domain inversion structure.
【０００９】[0009]
【作用および発明の効果】上記構成における周期ドメイ
ン反転構造とは、非線形光学効果を有する強誘電体の自
発分極（ドメイン）を周期的に反転させた構造である。
このような周期ドメイン反転構造を有する非線形光学材
料の結晶を用いて、基本波を第２高調波に波長変換する
方法が既にＢleombergenらによって提案されている（Ｐ
hys.Ｒev.,vol.127,Ｎo.６，1918（1962）参照）。この
方法においては、ドメイン反転部の周期Λを、
Λｃ＝２π／｛β（２ω）−２β（ω）｝ ……(1)
ただしβ（２ω）は第２高調波の伝搬定数
２β（ω）は基本波の伝搬定数
で与えられるコヒーレント長Λｃの整数倍になるように
設定することで、基本波と第２高調波との位相整合（疑
似位相整合）を取ることができる。周期ドメイン反転構
造を備えない非線形光学材料のバルク結晶を用いて波長
変換する場合は、位相整合する波長が結晶固有の特定波
長に限られるが、上記の方法によれば、任意の波長に対
して(1) を満足する周期Λを選択することにより、効率
良く位相整合を取ることが可能となる。The periodic domain inversion structure in the above structure is a structure in which the spontaneous polarization (domain) of a ferroelectric substance having a nonlinear optical effect is periodically inverted.
Bleombergen et al. Have already proposed a method of converting a fundamental wave into a second harmonic using a crystal of a nonlinear optical material having such a periodic domain inversion structure (P.
hys. Rev., vol. 127, No. 6, 1918 (1962)). In this method, the period Λ of the domain inversion part is represented by Λc = 2π / {β (2ω) -2β (ω)} (1) where β (2ω) is the propagation constant 2β (ω) of the second harmonic. Is set to be an integral multiple of the coherent length Λc given by the propagation constant of the fundamental wave, so that the fundamental wave and the second harmonic can be phase-matched (pseudo-phase matching). When wavelength conversion is performed using a bulk crystal of a non-linear optical material that does not have a periodic domain inversion structure, the phase matching wavelength is limited to a specific wavelength specific to the crystal, but according to the above method, By selecting the period Λ that satisfies (1), it is possible to achieve efficient phase matching.
【００１０】上記のような周期ドメイン反転構造による
位相整合領域と、角度位相整合または温度位相整合を果
たす位相整合領域とを１つの非線形光学材料の結晶に設
ければ、該結晶に入射したレーザービームを２回波長変
換することができ、２個の光波長変換素子を用いる場合
と同様に、極めて短波長の波長変換波が得られるように
なる。例えば、第１の位相整合領域において基本波の第
２高調波を発生させ、この第２高調波を第２の位相整合
領域においてさらにその第２高調波に変換すれば、結
局、元の基本波に対しては波長が１／４の第４高調波が
得られることになる。If a phase-matching region having the above-described periodic domain inversion structure and a phase-matching region that performs angular phase matching or temperature phase matching are provided in one crystal of a nonlinear optical material, the laser beam incident on the crystal will be described. Can be wavelength-converted twice, and a wavelength-converted wave having an extremely short wavelength can be obtained as in the case of using two optical wavelength conversion elements. For example, if the second harmonic of the fundamental wave is generated in the first phase matching region and the second harmonic is further converted into the second harmonic in the second phase matching region, the original fundamental wave is eventually obtained. As a result, the fourth harmonic having a wavelength of 1/4 is obtained.
【００１１】また、第１の位相整合領域において基本波
を第２高調波に変換し、第２の位相整合領域においてこ
の第２高調波と上記基本波の和周波を発生させれば、結
局、元の基本波に対しては波長が１／３の第３高調波が
得られることになる。なおこの場合、周期ドメイン反転
構造による位相整合領域を第２の位相整合領域とするの
であれば、ドメイン反転部の周期Λを、
Λｃ＝２π／［β（ω3 ）−｛β（ω1 ）＋β（ω2 ）｝］
ただしβ（ω3 ）は和周波の伝搬定数
β（ω1 ）は基本波の伝搬定数
β（ω2 ）は第２高調波の伝搬定数
で与えられるコヒーレント長Λｃの整数倍になるように
設定すれば、基本波および第２高調波と和周波との間で
良好に位相整合が取られる。If the fundamental wave is converted into the second harmonic wave in the first phase matching region and the sum frequency of the second harmonic wave and the fundamental wave is generated in the second phase matching region, eventually, With respect to the original fundamental wave, the third harmonic having a wavelength of ⅓ will be obtained. In this case, if the phase matching region having the periodic domain inversion structure is used as the second phase matching region, the period Λ of the domain inversion part is Λc = 2π / [β (ω 3 ) − {β (ω 1 ). + Β (ω 2 )}] where β (ω 3 ) is the propagation constant β (ω 1 ) of the sum frequency, the propagation constant β (ω 2 ) of the fundamental wave is the coherent length Λc given by the propagation constant of the second harmonic, If set to an integral multiple, good phase matching can be achieved between the fundamental wave and the second harmonic and the sum frequency.
【００１２】以上のように本発明の光波長変換素子は、
２個の光波長変換素子を用いる場合と同様に、極めて短
波長の波長変換波が得られるものであるが、１つの素子
であるから光通過端面は２面のみであり、よって前述し
たような光損失は、２個の光波長変換素子を用いて光通
過端面が４面となる場合よりも少なくなり、そこで高い
波長変換効率が得られるようになる。As described above, the optical wavelength conversion device of the present invention is
Similar to the case of using two optical wavelength conversion elements, an extremely short wavelength conversion wave can be obtained, but since it is one element, there are only two light passage end faces, and therefore, as described above. The light loss is smaller than that when two light wavelength conversion elements are used and the light passage end face has four surfaces, and high wavelength conversion efficiency can be obtained there.
【００１３】また、光通過端面が２面のみであれば、そ
れらの研磨およびコーティング作業も、２個の光波長変
換素子を用いて光通過端面が４面になる場合と比べてよ
り簡単になり、したがってこの光波長変換素子は比較的
低コストで作成可能となる。Further, if the light passing end faces are only two surfaces, the polishing and coating operations thereof are easier than the case where two light wavelength converting elements are used and the light passing end faces are four faces. Therefore, this light wavelength conversion element can be manufactured at a relatively low cost.
【００１４】なお上記構成の本発明の光波長変換素子に
おいては、第１および第２の位相整合領域に加えて、さ
らに１つあるいは複数の位相整合領域が適宜設けられて
もよいものである。そしてこの付加的に形成される位相
整合領域は、角度位相整合または温度位相整合を取る領
域であってもよいし、あるいは、周期ドメイン反転構造
を有して疑似位相整合を取る領域であってもよい。In the light wavelength conversion element of the present invention having the above-mentioned structure, one or more phase matching regions may be appropriately provided in addition to the first and second phase matching regions. The additionally formed phase matching region may be a region that achieves angular phase matching or temperature phase matching, or may be a region that has a periodic domain inversion structure and performs quasi phase matching. Good.
【００１５】[0015]
【実施例】以下、図面に示す実施例に基づいて本発明を
詳細に説明する。図１は、本発明の第１実施例による光
波長変換素子10を示すものである。この光波長変換素子
10は非線形光学材料であるＬＢＯの結晶９に、第１の位
相整合領域11および第２の位相整合領域12が形成されて
なるものである。この光波長変換素子10は、ペルチェ素
子13および図示しない温調回路により、24.3℃に保たれ
て使用される。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 1 shows an optical wavelength conversion device 10 according to a first embodiment of the present invention. This optical wavelength conversion element
Reference numeral 10 denotes a crystal 9 of LBO, which is a nonlinear optical material, in which a first phase matching region 11 and a second phase matching region 12 are formed. The light wavelength conversion element 10 is used while being kept at 24.3 ° C. by a Peltier element 13 and a temperature control circuit (not shown).
【００１６】上記ＬＢＯ結晶９は、光入射端面10ａおよ
び光出射端面10ｂに対して光学軸が図示の向きとなるよ
うにカットされている。図示しないレーザー光源から発
せられた波長λ1 ＝1212ｎｍのレーザービーム15は、第
１の位相整合領域11側の光入射端面10ａから光波長変換
素子10に入射せしめられる。そして光波長変換素子10
は、素子端面10ａにレーザービーム15が垂直入射し、ま
た図中矢印Ｐで示すレーザービーム15の直線偏光の向き
がＬＢＯ結晶９のＹ軸と平行となるように配置されてい
る。それにより基本波としてのレーザービーム15は、第
１の位相整合領域11において角度位相整合（ＮＣＰＭ：
non-critical phase matching ）を果たした上で波長λ
2 ＝λ1 ／２＝606 ｎｍの第２高調波16に波長変換され
る。The LBO crystal 9 is cut so that the optical axes thereof are oriented with respect to the light incident end face 10a and the light emitting end face 10b. A laser beam 15 having a wavelength λ 1 = 1212 nm emitted from a laser light source (not shown) is made incident on the light wavelength conversion element 10 from the light incident end face 10a on the first phase matching region 11 side. And the optical wavelength conversion element 10
Is arranged so that the laser beam 15 is vertically incident on the element end face 10a, and the direction of linearly polarized light of the laser beam 15 shown by an arrow P in the drawing is parallel to the Y axis of the LBO crystal 9. As a result, the laser beam 15 as the fundamental wave is angularly phase-matched (NCPM:
Non-critical phase matching) and wavelength λ
A 2 = λ 1/2 = 606 second harmonic 16 of nm are wavelength converted.
【００１７】なお、Ｙ軸方向に直線偏光したレーザービ
ーム15に対する第１の位相整合領域11の屈折率ｎY ＝1.
60であり、Ｚ軸方向に直線偏光した第２高調波16に対す
る第１の位相整合領域11の屈折率ｎZ ＝1.60である。ま
たこの第２高調波16の発生には、第１の位相整合領域11
の非線形光学定数ｄ32（＝ｄZYY ）が利用される。The refractive index n Y = 1.1.0 of the first phase matching region 11 for the laser beam 15 linearly polarized in the Y-axis direction.
60, and the refractive index n Z = 1.60 of the first phase matching region 11 for the second harmonic 16 linearly polarized in the Z-axis direction. In addition, in order to generate the second harmonic wave 16, the first phase matching region 11
The nonlinear optical constant d 32 (= d ZYY ) of is used.
【００１８】この第２高調波16は、光波長変換素子10の
第２の位相整合領域12に入射する。第２の位相整合領域
12は、ＬＢＯ結晶９に周期的に繰り返すドメイン反転部
18が形成されてなるものである。このような周期ドメイ
ン反転構造は、単分極化処理がなされたＬＢＯ結晶９
に、電子ビーム描画装置により電子線を照射して所定の
周期パターンを描画する、等により形成することができ
る。本実施例では、ドメイン反転部18の周期Λは7.6 μ
ｍとされている。波長λ2 ＝606 ｎｍの第２高調波16
は、このような周期ドメイン反転構造を有する第２の位
相整合領域12に入射し、そこで疑似位相整合を果たした
上で波長λ3 ＝λ2 ／２＝303 ｎｍの第２高調波（レー
ザービーム15に対しては第４高調波）17に波長変換され
る。この第４高調波17は、図中矢印Ｑで示すようにＺ軸
方向に直線偏光したものとなり、光波長変換素子10の光
出射端面10ｂから素子外に出射する。The second harmonic wave 16 is incident on the second phase matching region 12 of the optical wavelength conversion element 10. Second phase matching region
12 is a domain inversion part which is periodically repeated in the LBO crystal 9.
18 is formed. Such a periodic domain inversion structure has an LBO crystal 9 that has been monopolarized.
Further, it can be formed by irradiating an electron beam with an electron beam drawing device to draw a predetermined periodic pattern. In this embodiment, the period Λ of the domain inversion unit 18 is 7.6 μ.
It is supposed to be m. Second harmonic 16 with wavelength λ 2 = 606 nm
The second incident on the phase matching region 12, where the second harmonic of the wavelength λ 3 = λ 2/2 = 303 nm after having played a quasi-phase matched (laser beam having such a periodic domain inversion structure The wavelength of 15 is converted to the fourth harmonic) 17. The fourth harmonic 17 is linearly polarized in the Z-axis direction as indicated by arrow Q in the figure, and is emitted from the light emitting end face 10b of the light wavelength conversion element 10 to the outside of the element.
【００１９】なお、Ｚ軸方向に直線偏光した上記第２高
調波16に対する第２の位相整合領域12の屈折率ｎZ ＝1.
60であり、Ｚ軸方向に直線偏光した第４高調波17に対す
る第２の位相整合領域12の屈折率ｎZ ＝1.64である。ま
たこの第４高調波17の発生には、第２の位相整合領域12
の非線形光学定数ｄ33（＝ｄZZZ ）が利用される。The refractive index n Z = 1. 2 of the second phase matching region 12 with respect to the second harmonic wave 16 linearly polarized in the Z-axis direction.
60, and the refractive index n Z = 1.64 of the second phase matching region 12 for the fourth harmonic 17 linearly polarized in the Z-axis direction. In addition, in order to generate the fourth harmonic 17, the second phase matching region 12
The nonlinear optical constant d 33 (= d ZZZ ) of is used.
【００２０】上記の光波長変換素子10においては、２個
の光波長変換素子を用いる場合のように第２高調波16が
別の光波長変換素子に入射する際にその素子端面でフレ
ネル反射するということがなく、よって光損失が少なく
抑えられて、高い波長変換効率が得られる。本例では、
レーザービーム15のピークパワーが１ｋＷのとき、１Ｗ
のピークパワーの第４高調波17を得ることができる。さ
らに、この光波長変換素子10をレーザー共振器内に挿入
するような場合も、光通過端面は10ａおよび10ｂの２面
のみであるから、素子端面における光散乱が少なく抑え
られて、高い波長変換効率が得られるようになる。In the above-mentioned optical wavelength conversion element 10, when the second harmonic wave 16 is incident on another optical wavelength conversion element as in the case of using two optical wavelength conversion elements, Fresnel reflection occurs at the element end surface. Therefore, the optical loss can be suppressed to be small and high wavelength conversion efficiency can be obtained. In this example,
1W when the peak power of laser beam 15 is 1kW
It is possible to obtain the fourth harmonic 17 of the peak power of. Further, even when this optical wavelength conversion element 10 is inserted into a laser resonator, since the light passage end faces are only two faces, 10a and 10b, light scattering at the device end face is suppressed to a low level, and high wavelength conversion Efficiency is gained.
【００２１】また、光通過端面が10ａおよび10ｂの２面
のみであれば、それらの研磨およびコーティング作業
も、２個の光波長変換素子を用いて光通過端面が４面に
なる場合と比べてより簡単になり、したがってこの光波
長変換素子10は比較的低コストで作成可能となる。Further, when the light passing end faces are only two faces 10a and 10b, the polishing and coating operations thereof are also compared with the case where the light passing end faces are four faces by using two light wavelength conversion elements. It becomes simpler, and thus the optical wavelength conversion element 10 can be manufactured at a relatively low cost.
【００２２】次に図２を参照して、本発明の第２実施例
について説明する。なおこの図２において、図１中の要
素と同等の要素には同番号を付し、それらについての重
複した説明は省略する（以下、同様）。この第２実施例
の光波長変換素子20は、第１実施例の光波長変換素子10
と反対に、光入射端面20ａ側に形成された第１の位相整
合領域21が周期ドメイン反転構造を有して、レーザービ
ーム15と第２高調波16との間で疑似位相整合を取る領域
とされ、光出射端面20ｂ側に形成された第２の位相整合
領域22が、第２高調波16と第４高調波17との間で角度位
相整合を取る領域とされている。Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, elements that are the same as the elements in FIG. 1 are given the same numbers, and duplicated description thereof is omitted (the same applies hereinafter). The light wavelength conversion element 20 of the second embodiment is the same as the light wavelength conversion element 10 of the first embodiment.
On the contrary, the first phase matching region 21 formed on the side of the light incident end face 20a has a periodic domain inversion structure and has a pseudo phase matching between the laser beam 15 and the second harmonic wave 16. The second phase matching region 22 formed on the light emitting end face 20b side is a region where angular phase matching is performed between the second harmonic wave 16 and the fourth harmonic wave 17.
【００２３】この第２実施例の光波長変換素子20におい
ても、光通過端面は20ａおよび20ｂの２面のみであるか
ら、第１実施例と同様に、光損失を少なく抑えて高い波
長変換効率が得られ、またこの光波長変換素子10は比較
的低コストで作成可能なものとなる。Also in the light wavelength conversion element 20 of the second embodiment, since the light passing end faces are only two faces 20a and 20b, the light loss is suppressed to be small and the wavelength conversion efficiency is high as in the first embodiment. In addition, the light wavelength conversion element 10 can be manufactured at a relatively low cost.
【００２４】なお以上説明した２つの実施例において
は、第１の位相整合領域で基本波の第２高調波を発生さ
せ、第２の位相整合領域で上記第２高調波のさらに第２
高調波を発生させているが、それ以外の波長変換波を発
生させることも可能である。例えば、第１の位相整合領
域で基本波の第２高調波を発生させ、第２の位相整合領
域で上記第２高調波と基本波の和周波を発生させること
もできる。In the two embodiments described above, the second harmonic of the fundamental wave is generated in the first phase matching region and the second harmonic of the second harmonic is further generated in the second phase matching region.
Although harmonics are generated, it is also possible to generate other wavelength conversion waves. For example, the second harmonic of the fundamental wave can be generated in the first phase matching region, and the sum frequency of the second harmonic and the fundamental wave can be generated in the second phase matching region.
【００２５】次に図３を参照して、本発明の第３実施例
について説明する。この第３実施例の光波長変換素子30
は、光入射端面30ａ側に形成された第１の位相整合領域
31と、素子中央部に形成された第２の位相整合領域32と
に加えて、さらに光出射端面30ｂ側に第３の位相整合領
域33が形成されてなるものである。上記第１の位相整合
領域31および第３の位相整合領域33は周期ドメイン反転
構造を有して前述の疑似位相整合を果たす領域であり、
他方第２の位相整合領域32は前述の角度位相整合を果た
す領域である。Next, a third embodiment of the present invention will be described with reference to FIG. Optical wavelength conversion element 30 of the third embodiment
Is the first phase matching region formed on the light incident end face 30a side.
In addition to 31 and the second phase matching region 32 formed in the central portion of the device, a third phase matching region 33 is further formed on the light emitting end face 30b side. The first phase matching region 31 and the third phase matching region 33 are regions having a periodic domain inversion structure and performing the above-mentioned pseudo phase matching,
On the other hand, the second phase matching region 32 is a region that achieves the aforementioned angle phase matching.
【００２６】このような構成の光波長変換素子30におい
ては、例えば、光入射端面30ａから入射された基本波と
してのレーザービーム35を第１の位相整合領域31におい
て第２高調波36に変換し、この第２高調波36を第２の位
相整合領域32においてさらに第２高調波（レーザービー
ム35に対しては第４高調波）37に波長変換し、第３の位
相整合領域33において上記第２高調波36と第４高調波37
の和周波38を発生させることが可能である。In the optical wavelength conversion element 30 having such a structure, for example, the laser beam 35 as the fundamental wave incident from the light incident end face 30a is converted into the second harmonic wave 36 in the first phase matching region 31. The second harmonic wave 36 is wavelength-converted into the second harmonic wave (the fourth harmonic wave for the laser beam 35) 37 in the second phase matching area 32, and the second harmonic wave is converted into the third harmonic wave in the third phase matching area 33. 2nd harmonic 36 and 4th harmonic 37
It is possible to generate a sum frequency 38 of
【図１】本発明の第１実施例装置の斜視図FIG. 1 is a perspective view of a first embodiment device of the present invention.
【図２】本発明の第２実施例装置の斜視図FIG. 2 is a perspective view of a second embodiment device of the present invention.
【図３】本発明の第３実施例装置の斜視図FIG. 3 is a perspective view of a third embodiment device of the present invention.
９ ＬＢＯ結晶 10、20、30 光波長変換素子 10ａ、20ａ、30ａ 光入射端面 10ｂ、20ｂ、30ｂ 光出射端面 11、21、31 第１の位相整合領域 12、22、32 第２の位相整合領域 15、35 レーザービーム（基本波） 16、36 第２高調波 17、37 第４高調波 18 ドメイン反転部 33 第３の位相整合領域 38 和周波 9 LBO crystals 10, 20, 30 Optical wavelength conversion element 10a, 20a, 30a Light incident end face 10b, 20b, 30b Light emitting end face 11, 21, 31 First phase matching region 12, 22, 32 Second phase matching region 15, 35 laser beam (fundamental wave) 16, 36 Second harmonic 17,37 4th harmonic 18 domain inversion part 33 Third Phase Matching Area 38 Sum frequency
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平５−19310（ＪＰ，Ａ) Ｓｏｖｉｅｔ Ｔｅｃｈｎｉｃａｌ Ｐｈｙｓｉｃｓ Ｌｅｔｔｅｒｓ，Ｖｏ ｌ．６，Ｎｏ．３，ｐｐ．120−121 （1980) Ａ．Ｇ．Ａｒｕｔｙｕｎｙａｎ ｅｔ ａｌ. ─────────────────────────────────────────────────── ─── Continued front page (56) Reference JP-A-5-19310 (JP, A) Soviet Technical Physics Letters, Vo l. 6, No. 3, pp. 120-121 (1980) A. G. Artyuyunyan et al.
Claims (4)
に入射した基本波としてのレーザービームを波長変換す
る第１の位相整合領域と、この第１の位相整合領域から
出射した波長変換波をさらに波長変換する第２の位相整
合領域とが形成され、これら２つの位相整合領域の一方
が角度位相整合または温度位相整合を取る領域で、他方
が周期ドメイン反転構造を有して疑似位相整合を取る領
域であることを特徴とする光波長変換素子。1. A first phase-matching region for wavelength-converting a laser beam as a fundamental wave incident on the crystal of one nonlinear optical material, and a wavelength-converted wave emitted from the first phase-matching region. And a second phase matching region for further wavelength conversion are formed, one of these two phase matching regions is an angle phase matching or temperature phase matching region, and the other is a quasi phase matching having a periodic domain inversion structure. An optical wavelength conversion element, which is a region where
または温度位相整合を取る領域であり、前記第２の位相
整合領域が周期ドメイン反転構造を有して疑似位相整合
を取る領域であって、これらの領域が各々１つずつ形成
されていることを特徴とする請求項１記載の光波長変換
素子。2. The first phase matching region is a region for angular phase matching or temperature phase matching, and the second phase matching region is a region for quasi phase matching having a periodic domain inversion structure. The optical wavelength conversion element according to claim 1, wherein each of these regions is formed one by one.
反転構造を有して疑似位相整合を取る領域であり、前記
第２の位相整合領域が角度位相整合または温度位相整合
を取る領域であって、これらの領域が各々１つずつ形成
されていることを特徴とする請求項１記載の光波長変換
素子。3. The first phase matching region is a region having a periodic domain reversal structure to achieve quasi phase matching, and the second phase matching region is a region to achieve angular phase matching or temperature phase matching. The optical wavelength conversion element according to claim 1, wherein each of these regions is formed one by one.
反転構造を有して疑似位相整合を取る領域であり、前記
第２の位相整合領域が角度位相整合または温度位相整合
を取る領域であって、これらの領域が各々１つずつ形成
された上で、この第２の位相整合領域から出射した波長
変換波をさらに波長変換する、周期ドメイン反転構造を
有して疑似位相整合を取る第３の位相整合領域が形成さ
れていることを特徴とする請求項１記載の光波長変換素
子。4. The first phase matching region is a region having a periodic domain inversion structure to achieve quasi phase matching, and the second phase matching region is a region to achieve angular phase matching or temperature phase matching. Then, each of these regions is formed one by one, and the wavelength-converted wave emitted from the second phase matching region is further wavelength-converted. 2. The optical wavelength conversion device according to claim 1, wherein the phase matching region is formed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06650893A JP3447078B2 (en) | 1993-03-25 | 1993-03-25 | Optical wavelength conversion element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06650893A JP3447078B2 (en) | 1993-03-25 | 1993-03-25 | Optical wavelength conversion element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06281980A JPH06281980A (en) | 1994-10-07 |
| JP3447078B2 true JP3447078B2 (en) | 2003-09-16 |
Family
ID=13317854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06650893A Expired - Lifetime JP3447078B2 (en) | 1993-03-25 | 1993-03-25 | Optical wavelength conversion element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3447078B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2003262043A1 (en) | 2002-09-10 | 2004-04-30 | The Furukawa Electric Co., Ltd. | Wavelength conversion module |
-
1993
- 1993-03-25 JP JP06650893A patent/JP3447078B2/en not_active Expired - Lifetime
Non-Patent Citations (2)
| Title |
|---|
| Ａ．Ｇ．Ａｒｕｔｙｕｎｙａｎ ｅｔ ａｌ． |
| Ｓｏｖｉｅｔ Ｔｅｃｈｎｉｃａｌ Ｐｈｙｓｉｃｓ Ｌｅｔｔｅｒｓ，Ｖｏｌ．６，Ｎｏ．３，ｐｐ．１２０−１２１（１９８０） |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06281980A (en) | 1994-10-07 |
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