JP2004117774A - Diffraction grating and its manufacturing method - Google Patents
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C23/00—Other surface treatment of glass not in the form of fibres or filaments
- C03C23/0005—Other surface treatment of glass not in the form of fibres or filaments by irradiation
- C03C23/002—Other surface treatment of glass not in the form of fibres or filaments by irradiation by ultraviolet light
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/06—Glass compositions containing silica with more than 90% silica by weight, e.g. quartz
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
Abstract
Description
【０００１】
【発明の属する技術分野】
本発明は、熱に対して安定な回折格子およびその製造方法に関する。
【０００２】
【従来の技術】
ＳｉＯ２系ガラス材料に紫外線によって回折格子を書き込む技術は、１９８０年前後から盛んに研究され、１９９０年代には光ファイバー中に書き込んだ回折格子が光通信用バンドパスフィルターやファイバーの分散補償デバイスとして、実用化された。
【０００３】
通常、光ファイバーや平面導波路のコアには、ＧｅＯ２が添加されており、２４０ｎｍ付近を中心にして強い吸収帯が存在するので、紫外レーザーを効率よく吸収して屈折率が上昇する。その屈折率の上昇量は、０．０００１％前後であり、ブラッグ回折格子を形成するには小さすぎるので、１００気圧以上の高圧水素雰囲気下にガラスを数日間放置して、水素分子をガラスマトリックス内に充填した後、紫外線を照射する。この水素処理によって、通常、屈折率は一桁上昇し、効率の高い回折格子が形成できる。
【０００４】
しかしながら、上記の水素処理を伴う方法は、回折格子の製造コストを増大させるので、最近、ＧｅＯ２とともにＢ２Ｏ３を添加することが提案されている。この技術により、水素処理を行うことなく、０．００１％以上の屈折率上昇が実現された。しかしながら、ＧｅＯ２単独添加ガラス或いはＧｅＯ２とＢ２Ｏ３との共添加ガラスに書き込まれた回折格子は、耐熱性が悪く、使用可能温度の上限は、せいぜい８０℃程度である。
【０００５】
【発明が解決しようとする課題】
従って、本発明は、耐熱温度をさらに上げることにより、回折格子を利用する光デバイスの信頼性を向上させることを主な目的とする。
【０００６】
【課題を解決するための手段】
本発明者は、上記の課題を解決するために、鋭意研究を行った結果、特定組成のガラスに紫外線照射を行って予め回折格子を形成した後、当該回折格子を熱処理する場合には、８０℃を上回る耐熱性を備えた回折格子が得られることを見出した。
【０００７】
すなわち、本発明は、下記の回折格子および回折格子の形成方法を提供する。
１．ＧｅＯ２、Ｂ２Ｏ３およびＳｉＯ２からなるガラス材料に紫外線を照射することにより、ガラス材料の屈折率を周期的に変化させた後、当該材料を熱処理することを特徴とする回折格子の製造方法。
２．ガラス材料の組成がモル％比で、１≦ＧｅＯ２≦２０、１≦Ｂ２Ｏ３≦１４および６６≦ＳｉＯ２≦９８である上記項１に記載の回折格子の製造方法。
３．ガラス材料の熱処理を、５１０〜１１００℃において、１分間〜６時間行う上記項１に記載の回折格子の製造方法。
４．ガラス材料に照射する紫外線が、波長１５０〜４００ｎｍの紫外レーザーであり、そのパワー密度が１０ｍＪ／ｃｍ２以上である上記項１に記載の回折格子の製造方法。
５．ガラス材料に紫外レーザーを照射するに際し、位相マスクあるいは二光束干渉法による干渉縞を利用して、格子の周期を０．１〜５μｍに制御する上記項１に記載の方法。
６．プラズマＣＶＤ法を用いて作製したガラス材料を用いる上記項１に記載の回折格子の製造方法。
７．上記項１から６のいずれかに記載された方法により製造された回折格子。
【０００８】
【発明の実施の形態】
本発明による基礎ガラス材料は、ＧｅＯ２、Ｂ２Ｏ３およびＳｉＯ２からなる。ガラス材料中の各成分の組成比（モル％比）は、通常、１≦ＧｅＯ２≦２０、１≦Ｂ２Ｏ３≦１４および６６≦ＳｉＯ２≦９８である。この三成分の相対的な比が、規定範囲を外れる場合には、所望の特性を備えたガラス材料は得られない。例えば、ＧｅＯ２の量が少なすぎる場合には、紫外レーザーエネルギーに対する感応性が低くなり、目的とする回折格子が得られない。これに対し、ＧｅＯ２の量が過剰となる場合には、ガラスの耐候性が低下する。また、Ｂ２Ｏ３についても同様の傾向が認められる。三成分の相対的比は、より好ましくは、３≦ＧｅＯ２≦１６、３≦Ｂ２Ｏ３≦９および７５≦ＳｉＯ２≦９４である。
【０００９】
ガラス材料を作製する方法としては、特に限定されないが、プラズマＣＶＤ法によることが好ましい。例えば、原料として、Ｓｉ、Ｇｅ或いはＢをそれぞれ含有する公知の有機金属液体（テトラエトキシシラン、テトラメトキシゲルマニウム、トリメトキシボロンなど）を用いて、パワー２５０Ｗの高周波プラズマ中で、温度２５０〜５００℃程度に加熱された基板上にガラス材料を形成することができる。基板の種類は、上記加熱温度に耐える限り特に限定されないが、例えばＳｉＯ２、Ｓｉ、耐熱性結晶化ガラスなどを使うことができる。
【００１０】
次いで、上記組成領域のガラス材料に対し、位相マスクを介して紫外レーザーを照射するかあるいは紫外レーザーの干渉縞を照射すると、屈折率がマスクパターンあるいは干渉縞に応じて変化し、回折格子が形成される。当該回折格子の回折強度は、レーザー照射条件により、制御することができる。紫外レーザー照射条件は、通常レーザー波長が１５０〜４００ｎｍ程度（より好ましくは１９０〜２７０ｎｍ程度）であり、そのパワー密度が１０ｍＪ／ｃｍ２以上（より好ましくは５０〜２００ Ｊ／ｃｍ２程度である。紫外線の波長が上記値よりも短いかあるいは長い場合、或いはレーザーパワー密度が上記下限値よりも低い場合には、十分な回折強度の回折格子が得られない。また、レーザーパワー密度が強すぎる場合には、ガラス表面がアブレーションで損傷する危険性がある。
【００１１】
また、回折格子の周期は、後述の熱処理により回折効率を上昇させるために、格子の周期（高屈折率部分の巾と隣接する低屈折率部分の巾との和）は０．１〜５μｍの範囲内でなければならない。格子の周期が大きすぎる場合には、所定温度までの昇温過程で消失した格子が再び現れることがなくなる。これに対し、格子の周期が小さすぎる場合には、書き込みに使用するレーザーの波長と近い値となるので、鮮明な回折格子を描くことができず、また、熱処理による回折効率の上昇も認められない。
【００１２】
熱処理（アニール）は、大気中あるいは窒素中で行うことができ、その温度は５１０〜１１００℃程度の範囲内にある。加熱時間は、この温度範囲の低温域（５１０〜６００℃程度）では１〜６時間程度、高温域（６００〜１１００℃程度）では１〜数十分程度である。熱処理に際しては、昇温速度を制御することが望ましい。より具体的には、低温域および高温域の双方において、０．１〜１００℃／分程度（より好ましくは、０．５〜５０℃／分程度）で、所定の熱処理温度まで昇温することが好ましい。昇温速度を制御しない場合には、基板材料が割れるなどの弊害を生じる。
【００１３】
熱処理が不十分である（温度が低すぎる／または時間が短すぎる）場合には、耐熱性の高い回折格子が得られないのに対し、熱処理が過度となる（温度が高すぎるおよび／または時間が長すぎる）場合には、ガラスが軟化してしまい、一旦形成された回折格子が消失する。
【００１４】
また、実施例１にも示す様に、８≦ＧｅＯ２≦１７、４≦Ｂ２Ｏ３≦１０および７３≦ＳｉＯ２≦８８という組成のガラス材料については、５５０〜６５０℃程度の温度で１時間アニールした後、７５０〜８５０℃程度の温度で１時間程度アニールを繰り返すことにより、さらに高効率の回折格子が得られる。
【００１５】
【発明の効果】
本発明によれば、ＧｅＯ２、Ｂ２Ｏ３−ＳｉＯ２系ガラス材料において、レーザー照射とその後の熱処理により、回折格子を形成することができる。
【００１６】
この様にして得られた回折格子は、従来技術では実現不可能であった８０℃よりも高い温度でも回折効率が低下しないという極めて高度の耐熱性を発揮する。
【００１７】
この様な優れた特性を有する本発明の回折格子は、熱光学効果を利用した可変バンドパスフィルター、高温領域での温度／圧力などを検知するセンサーなどに極めて有用である。
【００１８】
【実施例】
以下に、実施例を示し、本発明の特徴とするところをさらに明確にする
実施例１
１４ＧｅＯ２−７Ｂ２Ｏ３−７９ＳｉＯ２（ｍｏｌ％）という組成のガラスをシリカ基板上に成膜した。すなわち、有機金属からなる原料（テトラエトキシシラン、テトラメトキシゲルマニウムおよびトリメトキシボロン）を８５℃で気化させ、２５０Ｗの高周波（ＲＦ）酸素プラズマ中で分解させて、４００℃のシリカ基板上に成膜した。
【００１９】
得られたガラス薄膜に対し、ＫｒＦエキシマレーザー（波長２４８ｎｍ、５０ｍＪ／ｃｍ２／パルス）を周期１０６０ｎｍの位相マスクを介して２８０００ショット照射した後、当該材料を６００℃の窒素雰囲気中で１時間熱処理した。その結果、波長６３３ｎｍにおいて回折効率０．０３％の回折格子が形成された。
【００２０】
得られた回折格子（周期１．０６μｍ）は、熱的に極めて安定であり、室温〜６００℃の間での熱処理を繰り返すと、回折効率はむしろ若干上昇し、劣化は全くみられなかった。
【００２１】
図１は、回折格子を所定の温度で１時間熱処理した場合の熱処理温度と回折効率との関係を示す。第１回の熱処理において、６００℃で効率が大きく上昇しており、その後は室温〜６００℃の間で熱処理を繰り返しても、回折効率は全く劣化しないことが明らかである。
【００２２】
また、上記で得た回折格子（６００℃熱処理物）をさらに８００℃で１時間熱処理することにより、図２に示す通り、回折効率が著しく上昇した。
実施例２
実施例１の手法に準じて、組成が１７ＧｅＯ２−１２Ｂ２Ｏ３−８１ＳｉＯ２（ｍｏｌ％）からなるガラスをシリカ基板上に成膜した後、ＡｒＦエキシマレーザー（波長１９８ｎｍ、４０ｍＪ／ｃｍ２／パルス）を周期１０６０ｎｍの位相マスクを介して３００００ショット照射し、その後、６００℃の窒素雰囲気中で１時間熱処理した。その結果、波長６３３ｎｍにおいて回折効率０．０３％の回折格子が形成された。
【００２３】
得られた回折格子（周期１．０６μｍ）は、室温〜６００℃の間で繰り返して熱処理しても回折効率が劣化しなかった。
実施例３
実施例１の手法に準じて、組成が５ＧｅＯ２−１４Ｂ２Ｏ３−７１ＳｉＯ２（ｍｏｌ％）からなるガラスをシリコン基板上に成膜した後、Ａｒレーザー（波長２４４ｎｍ、２０ｍＷ／ｃｍ２）の干渉光（周期５３０ｎｍ）を３０分間照射し、その後、８５０℃の空気雰囲気中で１０分熱処理した。その結果、実施例１のガラス材料と同様に回折効率０．０２％の回折格子が形成された。
【００２４】
得られた回折格子（周期１．０６μｍ）は、室温〜６００℃の間で繰り返して熱処理しても回折効率が劣化しなかった。
比較例１
実施例１の手法に準じて、組成が１４ＧｅＯ２−８６ＳｉＯ２（ｍｏｌ％）からなるガラスをシリカ基板上に成膜した後、ＫｒＦエキシマレーザー（波長２４８ｎｍ、８０ｍＪ／ｃｍ２／パルス）を周期１０６０ｎｍの位相マスクを介して３００００ショット照射した。
【００２５】
その時点で得られた回折格子（周期１．０６μｍ）の回折効率は、０．０００５％程度であったが、当該材料を５００℃の窒素雰囲気中で１時間熱処理したところ、回折格子は消失した。
比較例２
実施例１と同様な組成のガラスをシリカ基板上に成膜した後、実施例１と同様の手法に準じて、周期６μｍの回折格子を作製し、５００℃以上の温度で熱処理を行ったところ、回折現象は全く生じなくなった。
【図面の簡単な説明】
【図１】本発明の実施例１で得られた回折格子の熱処理による回折効率の変化を示すグラフである。
【図２】本発明の実施例１で得られた回折格子の再熱処理による回折効率の著しい上昇を示すグラフである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a diffraction grating that is stable against heat and a method for manufacturing the same.
[0002]
[Prior art]
The technique of writing a diffraction grating on a SiO 2 glass material using ultraviolet rays has been actively studied since around 1980. In the 1990s, the diffraction grating written in an optical fiber was used as a bandpass filter for optical communication and a dispersion compensation device for fiber. It was put to practical use.
[0003]
Usually, GeO 2 is added to the core of an optical fiber or a planar waveguide, and a strong absorption band exists around 240 nm, so that the ultraviolet laser is efficiently absorbed and the refractive index increases. Since the amount of increase in the refractive index is about 0.0001%, which is too small to form a Bragg diffraction grating, the glass is left in a high-pressure hydrogen atmosphere of 100 atm or more for several days to remove hydrogen molecules from the glass matrix. After filling the inside, ultraviolet rays are irradiated. By this hydrogen treatment, the refractive index is usually increased by one digit, and a highly efficient diffraction grating can be formed.
[0004]
However, since the method involving the above-mentioned hydrogen treatment increases the manufacturing cost of the diffraction grating, it has recently been proposed to add B 2 O 3 together with GeO 2 . By this technique, a refractive index increase of 0.001% or more was realized without performing hydrogen treatment. However, a diffraction grating written on GeO 2 single addition glass or a co-addition glass of GeO 2 and B 2 O 3 has poor heat resistance, and the upper limit of the usable temperature is at most about 80 ° C.
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to improve the reliability of an optical device using a diffraction grating by further increasing the heat resistance temperature.
[0006]
[Means for Solving the Problems]
The present inventor has conducted intensive studies to solve the above-described problems. As a result, when a diffraction grating is formed in advance by irradiating a glass having a specific composition with ultraviolet rays, and then heat-treating the diffraction grating, 80% It has been found that a diffraction grating having heat resistance higher than ℃ can be obtained.
[0007]
That is, the present invention provides the following diffraction grating and a method for forming the diffraction grating.
1. Manufacturing a diffraction grating characterized by irradiating a glass material made of GeO 2 , B 2 O 3, and SiO 2 with ultraviolet light to periodically change the refractive index of the glass material and then heat-treating the material. Method.
2. Item 2. The method for producing a diffraction grating according to the above item 1, wherein the composition of the glass material satisfies 1 ≦ GeO 2 ≦ 20, 1 ≦ B 2 O 3 ≦ 14 and 66 ≦ SiO 2 ≦ 98 in terms of mol%.
3. Item 2. The method for producing a diffraction grating according to Item 1, wherein the heat treatment of the glass material is performed at 510 to 1100 ° C. for 1 minute to 6 hours.
4. Item 2. The method for producing a diffraction grating according to Item 1, wherein the ultraviolet light applied to the glass material is an ultraviolet laser having a wavelength of 150 to 400 nm, and the power density thereof is 10 mJ / cm 2 or more.
5. 2. The method according to the above item 1, wherein when irradiating the glass material with an ultraviolet laser, the period of the grating is controlled to 0.1 to 5 μm by using a phase mask or interference fringes by two-beam interference method.
6. Item 2. The method for manufacturing a diffraction grating according to Item 1, wherein a glass material manufactured by using a plasma CVD method is used.
7. Item 7. A diffraction grating manufactured by the method according to any one of Items 1 to 6.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The basic glass material according to the invention consists of GeO 2 , B 2 O 3 and SiO 2 . The composition ratio (molar% ratio) of each component in the glass material is usually 1 ≦ GeO 2 ≦ 20, 1 ≦ B 2 O 3 ≦ 14 and 66 ≦ SiO 2 ≦ 98. If the relative ratio of these three components is out of the specified range, a glass material having desired characteristics cannot be obtained. For example, if the amount of GeO 2 is too small, the sensitivity to ultraviolet laser energy becomes low, and a desired diffraction grating cannot be obtained. On the other hand, when the amount of GeO 2 is excessive, the weather resistance of the glass decreases. A similar tendency is observed for B 2 O 3 . The relative proportions of the three components are more preferably 3 ≦ GeO 2 ≦ 16, 3 ≦ B 2 O 3 ≦ 9 and 75 ≦ SiO 2 ≦ 94.
[0009]
The method for producing the glass material is not particularly limited, but is preferably a plasma CVD method. For example, using a known organic metal liquid (tetraethoxysilane, tetramethoxygermanium, trimethoxyboron, or the like) containing Si, Ge or B as a raw material in a high-frequency plasma with a power of 250 W and a temperature of 250 to 500 ° C. A glass material can be formed on a moderately heated substrate. The type of the substrate is not particularly limited as long as it can withstand the above-mentioned heating temperature. For example, SiO 2 , Si, heat-resistant crystallized glass, or the like can be used.
[0010]
Next, when the glass material in the above composition region is irradiated with an ultraviolet laser or an interference fringe of the ultraviolet laser through a phase mask, the refractive index changes according to the mask pattern or the interference fringe, and a diffraction grating is formed. Is done. The diffraction intensity of the diffraction grating can be controlled by laser irradiation conditions. The ultraviolet laser irradiation conditions are usually such that the laser wavelength is about 150 to 400 nm (more preferably, about 190 to 270 nm), and the power density is 10 mJ / cm 2 or more (more preferably, about 50 to 200 J / cm 2 ). When the wavelength of the ultraviolet light is shorter or longer than the above value, or when the laser power density is lower than the above lower limit, a diffraction grating having a sufficient diffraction intensity cannot be obtained. Has the risk that the glass surface will be damaged by ablation.
[0011]
The period of the diffraction grating (the sum of the width of the high-refractive-index portion and the width of the adjacent low-refractive-index portion) is 0.1 to 5 μm in order to increase the diffraction efficiency by heat treatment described later. Must be within range. If the lattice period is too large, the lattice disappeared in the process of raising the temperature to the predetermined temperature will not appear again. On the other hand, if the period of the grating is too small, a value close to the wavelength of the laser used for writing cannot be drawn, and a clear diffraction grating cannot be drawn. Absent.
[0012]
The heat treatment (annealing) can be performed in the air or in nitrogen, and the temperature is in the range of about 510 to 1100 ° C. The heating time is about 1 to 6 hours in a low temperature range (about 510 to 600 ° C.) and about 1 to several tens of minutes in a high temperature range (about 600 to 1100 ° C.). During the heat treatment, it is desirable to control the rate of temperature rise. More specifically, in both the low temperature range and the high temperature range, the temperature is raised to a predetermined heat treatment temperature at about 0.1 to 100 ° C./min (more preferably, about 0.5 to 50 ° C./min). Is preferred. If the heating rate is not controlled, adverse effects such as cracking of the substrate material will occur.
[0013]
If the heat treatment is insufficient (the temperature is too low and / or the time is too short), a diffraction grating having high heat resistance cannot be obtained, but the heat treatment becomes excessive (the temperature is too high and / or the time is too short). Is too long), the glass softens, and the diffraction grating once formed disappears.
[0014]
Further, as shown in Example 1, for a glass material having a composition of 8 ≦ GeO 2 ≦ 17, 4 ≦ B 2 O 3 ≦ 10, and 73 ≦ SiO 2 ≦ 88, a temperature of about 550 to 650 ° C. After annealing for one hour, annealing is repeated at a temperature of about 750 to 850 ° C. for about one hour to obtain a diffraction grating with higher efficiency.
[0015]
【The invention's effect】
According to the present invention, a diffraction grating can be formed in a GeO 2 , B 2 O 3 —SiO 2 -based glass material by laser irradiation and subsequent heat treatment.
[0016]
The diffraction grating thus obtained exhibits a very high heat resistance such that the diffraction efficiency does not decrease even at a temperature higher than 80 ° C., which cannot be realized by the prior art.
[0017]
The diffraction grating of the present invention having such excellent characteristics is extremely useful for a variable bandpass filter utilizing a thermo-optic effect, a sensor for detecting temperature / pressure in a high temperature region, and the like.
[0018]
【Example】
Hereinafter, Examples will be described, and Examples 1 to further clarify features of the present invention.
The 14GeO 2 -7B 2 O 3 -79SiO 2 glass (mol%) of the composition was formed on the silica substrate. That is, a raw material (tetraethoxysilane, tetramethoxygermanium, and trimethoxyboron) composed of an organic metal is vaporized at 85 ° C., decomposed in a 250 W radio frequency (RF) oxygen plasma, and formed on a silica substrate at 400 ° C. did.
[0019]
The obtained glass thin film is irradiated with KrF excimer laser (wavelength: 248 nm, 50 mJ / cm 2 / pulse) through a phase mask having a period of 1060 nm for 28,000 shots, and the material is heat-treated in a nitrogen atmosphere at 600 ° C. for 1 hour. did. As a result, a diffraction grating having a diffraction efficiency of 0.03% at a wavelength of 633 nm was formed.
[0020]
The obtained diffraction grating (period: 1.06 μm) was extremely stable thermally, and when heat treatment was repeated at a temperature between room temperature and 600 ° C., the diffraction efficiency was rather increased and no deterioration was observed.
[0021]
FIG. 1 shows the relationship between the heat treatment temperature and the diffraction efficiency when the diffraction grating is heat-treated at a predetermined temperature for one hour. In the first heat treatment, the efficiency is greatly increased at 600 ° C., and it is apparent that even if the heat treatment is repeated between room temperature and 600 ° C., the diffraction efficiency does not deteriorate at all.
[0022]
Further, when the diffraction grating (heat-treated product at 600 ° C.) obtained above was further heat-treated at 800 ° C. for 1 hour, the diffraction efficiency was significantly increased as shown in FIG.
Example 2
According to the procedure of Example 1, after the glass having the composition has 17GeO 2 -12B 2 O 3 -81SiO 2 (mol%) was formed on a silica substrate, ArF excimer laser (wavelength 198nm, 40mJ / cm 2 / Pulse) was irradiated through a phase mask having a period of 1060 nm for 30,000 shots, and then heat-treated in a nitrogen atmosphere at 600 ° C. for 1 hour. As a result, a diffraction grating having a diffraction efficiency of 0.03% at a wavelength of 633 nm was formed.
[0023]
The diffraction efficiency of the obtained diffraction grating (period: 1.06 μm) was not deteriorated even after repeated heat treatment between room temperature and 600 ° C.
Example 3
According to the procedure of Example 1, composition after forming a glass consisting 5GeO 2 -14B 2 O 3 -71SiO 2 (mol%) on the silicon substrate, Ar laser (wavelength 244nm, 20mW / cm 2) of Irradiation with interference light (period: 530 nm) was performed for 30 minutes, and then heat treatment was performed for 10 minutes in an air atmosphere at 850 ° C. As a result, a diffraction grating having a diffraction efficiency of 0.02% was formed similarly to the glass material of Example 1.
[0024]
The diffraction efficiency of the obtained diffraction grating (period: 1.06 μm) was not deteriorated even after repeated heat treatment between room temperature and 600 ° C.
Comparative Example 1
According to the procedure of Example 1, after the glass composition consisting 14GeO 2 -86SiO 2 (mol%) was formed on a silica substrate, KrF excimer laser (wavelength 248nm, 80mJ / cm 2 / pulse) periodically 1060nm 30,000 shots were radiated through the phase mask.
[0025]
The diffraction efficiency of the diffraction grating (period 1.06 μm) obtained at that time was about 0.0005%. However, when the material was heat-treated in a nitrogen atmosphere at 500 ° C. for 1 hour, the diffraction grating disappeared. .
Comparative Example 2
After a glass having the same composition as in Example 1 was formed on a silica substrate, a diffraction grating having a period of 6 μm was prepared and heat-treated at a temperature of 500 ° C. or higher according to the same method as in Example 1. The diffraction phenomenon did not occur at all.
[Brief description of the drawings]
FIG. 1 is a graph showing a change in diffraction efficiency due to heat treatment of a diffraction grating obtained in Example 1 of the present invention.
FIG. 2 is a graph showing a remarkable increase in diffraction efficiency due to re-heat treatment of the diffraction grating obtained in Example 1 of the present invention.
Claims (7)
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006134983A1 (en) * | 2005-06-17 | 2006-12-21 | Asahi Glass Company, Limited | Windowpane |
| JP2007530281A (en) * | 2004-03-27 | 2007-11-01 | レーザー−ラボラトリウム・ゲッティンゲン・アインゲトラーゲナー・フェライン | Method for manufacturing optical components by surface structured laser processing |
| JP2010522330A (en) * | 2007-03-22 | 2010-07-01 | ゼネラル・エレクトリック・カンパニイ | Fiber optic sensor for detecting multiple parameters in harsh environments |
| US8547008B2 (en) | 2006-01-12 | 2013-10-01 | Ppg Industries Ohio, Inc. | Material having laser induced light redirecting features |
| US8629610B2 (en) | 2006-01-12 | 2014-01-14 | Ppg Industries Ohio, Inc. | Display panel |
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2002
- 2002-09-26 JP JP2002280321A patent/JP3928042B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007530281A (en) * | 2004-03-27 | 2007-11-01 | レーザー−ラボラトリウム・ゲッティンゲン・アインゲトラーゲナー・フェライン | Method for manufacturing optical components by surface structured laser processing |
| JP4832423B2 (en) * | 2004-03-27 | 2011-12-07 | レーザー−ラボラトリウム・ゲッティンゲン・アインゲトラーゲナー・フェライン | Method for manufacturing optical components by surface structured laser processing |
| WO2006134983A1 (en) * | 2005-06-17 | 2006-12-21 | Asahi Glass Company, Limited | Windowpane |
| US8547008B2 (en) | 2006-01-12 | 2013-10-01 | Ppg Industries Ohio, Inc. | Material having laser induced light redirecting features |
| US8629610B2 (en) | 2006-01-12 | 2014-01-14 | Ppg Industries Ohio, Inc. | Display panel |
| JP2010522330A (en) * | 2007-03-22 | 2010-07-01 | ゼネラル・エレクトリック・カンパニイ | Fiber optic sensor for detecting multiple parameters in harsh environments |
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