JP2002221477A - Proximity field optical probe, proximity field optical microscope using the same and optical recording / reproducing apparatus - Google Patents
Proximity field optical probe, proximity field optical microscope using the same and optical recording / reproducing apparatusInfo
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- JP2002221477A JP2002221477A JP2001016500A JP2001016500A JP2002221477A JP 2002221477 A JP2002221477 A JP 2002221477A JP 2001016500 A JP2001016500 A JP 2001016500A JP 2001016500 A JP2001016500 A JP 2001016500A JP 2002221477 A JP2002221477 A JP 2002221477A
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- optical probe
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、近接場光学顕微鏡
もしくは近接場を用いた光記録/再生装置において用い
る近接場光プローブに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a near-field optical probe used in a near-field optical microscope or an optical recording / reproducing apparatus using a near-field.
【０００２】[0002]
【従来の技術】従来の光学顕微鏡では、光はレンズを用
いて集光させる。この場合、分解能は光波長により制限
される。これに対し近接場光学顕微鏡では、レンズの代
わりに、寸法がナノメートルオーダーの微小構造、例え
ば径が光波長以下の微小開口を用いて光を集光させる。
光をこの微小構造に当てると、その微小構造近傍には近
接場光と呼ばれる局在した光が発生する。この近接場光
を試料近傍に近づけ、試料表面上を走査させることによ
り、微小構造の寸法で決まる分解能で試料の形状や光学
特性を測定することができる。近年この顕微鏡は、生体
試料、半導体量子構造、高分子材料等の形状測定や分
光、および高密度光記録など幅広い分野に応用され始め
ている。2. Description of the Related Art In a conventional optical microscope, light is focused using a lens. In this case, the resolution is limited by the light wavelength. On the other hand, in the near-field optical microscope, instead of a lens, light is condensed using a minute structure having a dimension on the order of nanometers, for example, a minute aperture having a diameter equal to or smaller than a light wavelength.
When light is applied to this minute structure, localized light called near-field light is generated near the minute structure. By bringing this near-field light close to the vicinity of the sample and scanning the surface of the sample, the shape and optical characteristics of the sample can be measured at a resolution determined by the size of the microstructure. In recent years, this microscope has begun to be applied to a wide range of fields such as shape measurement and spectroscopy of biological samples, semiconductor quantum structures, and polymer materials, and high-density optical recording.
【０００３】近接場光を発生させる構造（近接場光プロ
ーブ）としては、光波長以下の微小開口をもつ先鋭化さ
れた光ファイバ（光ファイバ・プローブ）が広く用いら
れる。このファイバ・プローブは、光ファイバの一端
を、加熱しながら引き伸ばしたり、化学エッチング法を
用いることにより先鋭化した後、先端以外を金属でコー
ティングすることにより作製される。光ファイバに光を
導入することにより、先端に形成された微小開口近傍に
近接場光を発生させることができる。As a structure for generating near-field light (near-field optical probe), a sharpened optical fiber (optical fiber probe) having a minute aperture smaller than the light wavelength is widely used. This fiber probe is manufactured by stretching one end of an optical fiber while heating it, or sharpening it by using a chemical etching method, and then coating the other end with a metal. By introducing light into the optical fiber, near-field light can be generated in the vicinity of a minute opening formed at the tip.
【０００４】しかし上記のファイバ・プローブは、光利
用効率が低いという欠点を持つ。例えば開口径が100nm
のとき、ファイバに入射する光の強度とファイバ先端か
ら出射する光の強度の比は0.001％以下である（Applied
Physics Letters, （和名）アプライドフィジックスレ
ターズ, Vol.68, No 19, p2612-2614,1996）。この問題
点を克服するために、つぎのようなプローブが提案され
ている。（1）多段階先鋭化ファイバ・プローブ：ファ
イバ先端のとがり角を、根元から先端に行くにしたがい
2段階または３段階に変化させたファイバ・プローブ（A
pplied Physics Letters, （和名）アプライドフィジッ
クスレターズ, Vol.68, No 19, p2612-2614,1996; Appl
ied Physics Letters, （和名）アプライドフィジック
スレターズ, Vol. 73, No.15, p2090-2092,1998）。
（２）金属針プローブ：STMの針をプローブとして使
う。針先端に光を照射することにより、先端近傍に強い
近接場光を発生させる。（特開平6-137847）（３）金属
微小球つき微小開口ファイバ・プローブ：先端の微小開
口の中心に金属の微小球が形成されたファイバ・プロー
ブ（特開平11-101809、本第一発明者らにより提案）。
微小開口から出射した光により、金属微小球中にプラズ
モンが励起され、金属球近傍に強い近接場光が発生す
る。(４) 金属の散乱体つきガラス基板プローブ：ガラ
ス基板底面に金属の散乱体をつけたプローブ。金属の散
乱体近傍に発生する強い近接場光を用いる（特開平11-2
50460）。(５)ボウタイアンテナプローブ：中心に幅が
電磁波の波長以下のギャップを持つ２つの台形型金属ア
ームを平面基板上に形成したプローブ。適当な向きに偏
光した電磁波を入射させると、ギャップに局在した電磁
波が発生する（United States Patents 5696372）。た
だし、実施例はマイクロ波に対してのみである。(6) 三
角形の金属パターンを平面基板に形成したプローブ：頂
点の曲率半径が数10nm以下の三角形の金属パターンを平
面基板上に形成したプローブ。適当な向きに偏光した光
を入射させると、頂点に局在した近接場光が発生する。
特に、入射光の波長をプラズモンの共鳴に合せることに
より非常に強い近接場光を発生させることが出来る。上
記の三角形のパターンを２つ、それぞれの頂点の間隔が
数10nm以下になるように配置したプローブも提案されて
おり。この場合、頂点間に局在した近接場光が発生する
（Technical Digest of 6th international conference
on near field optics and related techniques, theN
etherlands, Aug. 27-31, 2000, p55）。（7）四角錘の
２つの側面に金属膜を形成したプローブ：四角錘の４つ
の側面のうち対向する２つの側面に金属の膜を形成し、
かつ頂点に幅が光波長以下のギャップを形成したプロー
ブ。ギャップ部に強い近接場光が発生する（Technical
Digest of 6th international conference on near fie
ld optics and related techniques, the Netherlands,
Aug. 27-31, 2000, p100）。[0004] However, the above-mentioned fiber probe has a drawback that light utilization efficiency is low. For example, the opening diameter is 100nm
In this case, the ratio of the intensity of light entering the fiber to the intensity of light exiting from the fiber tip is 0.001% or less (Applied
Physics Letters, (Japanese name) Applied Physics Letters, Vol. 68, No 19, p2612-2614, 1996). In order to overcome this problem, the following probe has been proposed. (1) Multi-stage sharpened fiber probe: The tip angle of the fiber tip goes from the root to the tip.
Fiber probe with two or three stages (A
pplied Physics Letters, (Japanese name) Applied Physics Letters, Vol. 68, No 19, p2612-2614, 1996; Appl
ied Physics Letters, (Japanese name) Applied Physics Letters, Vol. 73, No. 15, p2090-2092, 1998).
(2) Metal needle probe: STM needle is used as a probe. By irradiating light to the needle tip, strong near-field light is generated near the tip. (3) Micro-aperture fiber probe with metal micro-spheres: Fiber probe in which metal micro-spheres are formed at the center of the micro-aperture at the tip (Japanese Patent Laid-Open No. 11-101809, the first inventor Et al.).
Plasmons are excited in the metal microspheres by the light emitted from the microscopic aperture, and strong near-field light is generated near the metal spheres. (4) Glass substrate probe with metal scatterer: A probe with a metal scatterer attached to the bottom of the glass substrate. Uses strong near-field light generated near a metal scatterer (Japanese Patent Laid-Open No. 11-2
50460). (5) Bow-tie antenna probe: A probe in which two trapezoidal metal arms having a gap whose width is equal to or smaller than the wavelength of an electromagnetic wave at the center are formed on a flat substrate. When an electromagnetic wave polarized in an appropriate direction is incident, an electromagnetic wave localized in the gap is generated (United States Patents 5696372). However, the embodiment is only for microwaves. (6) Probe in which a triangular metal pattern is formed on a flat substrate: A probe in which a triangular metal pattern having a vertex with a radius of curvature of several tens nm or less is formed on a flat substrate. When light polarized in an appropriate direction is incident, near-field light localized at the vertex is generated.
Particularly, by adjusting the wavelength of the incident light to the plasmon resonance, very strong near-field light can be generated. A probe has also been proposed in which two of the above triangular patterns are arranged such that the distance between the vertices is several tens of nanometers or less. In this case, near-field light is generated localized in between the vertices (Technical Digest of 6 th international conference
on near field optics and related techniques, theN
etherlands, Aug. 27-31, 2000, p55). (7) Probe in which metal films are formed on two side surfaces of a quadrangular pyramid: a metal film is formed on two opposing side surfaces of four side surfaces of a quadrangular pyramid,
A probe having a gap at the vertex whose width is equal to or smaller than the light wavelength. Strong near-field light is generated in the gap (Technical
Digest of 6 th international conference on near fie
ld optics and related techniques, the Netherlands,
Aug. 27-31, 2000, p100).
【０００５】[0005]
【発明が解決しようとする課題】上記従来例(6)の三角
形の金属パターンを使った近接場光プローブは、非常に
強い近接場光を発生させることができる。特に光波長を
プラズモン共鳴波長に合わせることにより、強度が入射
光強度と比べ数100倍以上の、非常に強い近接場光を発
生させることが出来る。しかし、このように金属のパタ
ーンを平面基板の底面に形成した場合、広い面積にわた
ってプローブが平坦になっているので、生体試料など表
面に凹凸がある試料を観察する場合、強い近接場光が発
生する三角形の頂点またはギャップに試料表面を近づけ
ることが困難になる。従来例(7)の四角錐の２つの面を
金属膜で覆ったプローブも従来例（6）と同様、強い近
接場光を発生させることが出来、近接場光を発生させる
部分が突き出ているので、凹凸のある試料に対しても使
用することができる。しかし、構造が立体的であるた
め、四角錐の頂点に幅が数10 nm 以下の微小なギャップ
を形成することは容易ではなく、大量生産は難しい。例
えば従来例(7)では、四角錐の4つの面を金属で覆った
後、Focused Ion Beam エッチング装置を用いて微小な
ギャップを作製しているが、作製可能なギャップ間隔は
100 nm 程度と大きく、またギャップを形成する場所を
一つ一つ観察しながら指定する必要があるため、大量生
産も不可能である。本発明は、光利用高率が高く、凹凸
のある試料表面に対しても使用可能で、かつ大量製産可
能な近接場光プローブを提供することを目的とする。The near-field light probe using the triangular metal pattern of the prior art (6) can generate very strong near-field light. Particularly, by adjusting the light wavelength to the plasmon resonance wavelength, it is possible to generate a very strong near-field light whose intensity is several hundred times or more as compared with the incident light intensity. However, when a metal pattern is formed on the bottom surface of a flat substrate in this way, the probe is flat over a large area, so when observing a sample such as a biological sample having irregularities on the surface, strong near-field light is generated. It is difficult to bring the sample surface closer to the apex or gap of the triangle. Similarly to the conventional example (6), the probe in which the two surfaces of the quadrangular pyramid of the conventional example (7) are covered with a metal film can generate strong near-field light, and the portion that generates the near-field light protrudes. Therefore, it can be used for a sample having irregularities. However, since the structure is three-dimensional, it is not easy to form a small gap having a width of several tens of nm or less at the apex of the pyramid, and mass production is difficult. For example, in the conventional example (7), after covering the four surfaces of the quadrangular pyramid with metal, a minute gap is formed using a focused ion beam etching apparatus.
Large-scale production is not possible because it is large, about 100 nm, and it is necessary to specify the location where the gap is formed while observing it one by one. An object of the present invention is to provide a near-field optical probe which has a high light utilization ratio, can be used even on a sample surface having irregularities, and can be mass-produced.
【０００６】[0006]
【課題を解決するための手段】本発明の近接場光プロー
ブでは、三角錐や四角錘などの多角錘の突起の側面のう
ちの１つの面のみを金属膜で覆う。このプローブに光を
入射させると金属膜の先端部（突起の頂点部）に電荷が
集中し、先端部に大きなダイポール（分極）が発生す
る。ここに試料を近づけると、金属膜先端に発生したダ
イポールのイメージダイポールが試料側に発生する。こ
れは、従来例(8)の２つの金属膜のうち、一方の膜が試
料中に形成されるのに等しく、金属膜と試料に発生する
２つのダイポールが互いに相互作用する結果、プローブ
先端と試料の間に強い近接場光が発生する。特に、入射
光の光波長を、金属膜中に発生するプラズモンの共鳴波
長に合わせることにより、強い近接場光を発生させるこ
とが出来る。このプローブは、多角錐の１つの面を金属
で覆うのみで作製可能で大量生産が可能である。In the near-field optical probe according to the present invention, only one of the side surfaces of the projection of a polygonal pyramid such as a triangular pyramid or a quadrangular pyramid is covered with a metal film. When light is incident on this probe, charges are concentrated on the tip of the metal film (apex of the protrusion), and a large dipole (polarization) is generated at the tip. When the sample is approached here, an image dipole of a dipole generated at the tip of the metal film is generated on the sample side. This is equivalent to one of the two metal films of the conventional example (8) being formed in the sample, and the metal film and the two dipoles generated in the sample interact with each other. Strong near-field light is generated between the samples. In particular, strong near-field light can be generated by adjusting the light wavelength of the incident light to the resonance wavelength of the plasmon generated in the metal film. This probe can be manufactured simply by covering one surface of the polygonal pyramid with metal, and can be mass-produced.
【０００７】[0007]
【発明の実施の形態】以下本発明の具体的な実施の形態
について説明する。本発明のプローブは三角錐や四角錘
などの多角錘の形状をした突起およびその側面に形成さ
れた金属膜で形成される。図1に突起の形状が四角錐で
ある場合のプローブの構造を示す。四角錐の形状をした
突起は光透過性を持つ材料で構成され、突起の側面のう
ちの１つの面（11）すべてが金属で覆で覆われ、その他
の面12は金属で覆われていない。このプローブに矢印15
で示した方向に偏光した光を入射させると、金属中の電
子が振動し、頂点13に電子が集中する。その結果、図２
のように頂点13に大きなダイポール（分極）２１が発生
する。このプローブ先端に試料を近づけると、試料25側
にダイポール21のイメージダイポール22が発生し、二つ
のダイポール21と22が相互作用する結果、プローブ先端
１３と試料間に強い近接場光26が発生する。光は突起の
外側から入射させても良いし（図１矢印16）、突起が光
透過性のある材料で形成されている場合、突起の内側か
ら入射させても良い（図１矢印14）。突起を構成する材
料は例えばSi やSiO2、SiNなどにする。金属の膜には例
えば金、銀、アルミなどを用いる。金属膜の厚さは数10
0nm以下であれば良く、例えば30 nmにする。頂点13にお
ける金属膜の端の曲率半径は100 nm以下であれば良い
が、高い分解能を実現するためには、小さい方が好まし
い。例えば曲率半径は20 nmにする。上記のプローブに
入射させる光の波長は、金属膜中の電子のプラズマ振動
の共鳴点（プラズモン共鳴点）に合わせるのが好まし
い。例として、突起の側面に形成された金属膜を平面的
な三角形の形状をした金属膜と近似して計算した、近接
場光強度と光波長の関係をを図3に示す。この値はFDTD
法（Journal of Optical Society of America A, Vol.1
2, No.9, p1974-1983, 1995, （和名）ジャーナルオブ
オプティカルソサエティオブアメリカA）を用いて計算
した値である。この計算においては、三角形の膜の材質
は金、膜厚＝30nm、先端曲率半径＝25nm、頂点の頂角＝
40°とし、この膜がＸＹ方向の面内に置かれているとし
た（金属膜は空気中に置かれているものとた）。波源は
金属パターンからＺ方向に1波長離れた位置に置かれて
いるとし、波源からは平面波がＺ方向に発生していると
した。解析領域の大きさはx,y,zそれぞれの方向に0.3×
0.2×2.6μmとし、解析領域の境界条件にはｘ軸、ｙ軸
に垂直な面で周期境界条件、ｚ軸に垂直な面で吸収境界
条件を用いた。波源と吸収境界の間隔は1波長とした。
メッシュ数はx,y,zそれぞれの方向に60×50×60とし、
三角形膜の頂点付近で間隔が小さくなる不均一メッシュ
を用い、三角形膜の頂点付近でのメッシュ間隔は2.5nm
とした。時間刻み幅は1×10-18秒、計算繰り返し回数は
15000回とした。縦軸は頂点部の近接場光強度と入射光
のパワー密度の比を表す。このように650 nm付近に共鳴
波長があり、そのとき近接場光強度が最大となる。な
お、上記の計算では金属膜は空気中にあるとしたが、実
際に金属膜は突起の表面に形成され、また頂点近傍には
試料も近づく。その結果、実際の共鳴波長はこの上記の
共鳴波長より多少ずれると考えられる。上記の突起は、
面発光レーザーなどの半導体レーザーの出射面に形成し
ても良い。半導体レーザーを出射した光は、頂点にある
金属膜の先端により散乱され、強い近接場光が頂点に発
生する。このように光源とプローブを一体化させること
により、光源とプローブの位置合わせが不要になる。上
記の突起は、共振器の出射面に形成しても良い。これに
より光利用効率がさらに向上する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. The probe of the present invention is formed of a projection in the shape of a polygonal pyramid such as a triangular pyramid or a quadrangular pyramid, and a metal film formed on a side surface thereof. FIG. 1 shows the structure of the probe when the shape of the protrusion is a quadrangular pyramid. The protrusion in the shape of a quadrangular pyramid is made of a light-transmitting material, and one of the side surfaces (11) of the protrusion is entirely covered with metal, and the other surface 12 is not covered with metal. . Arrow 15 on this probe
When light polarized in the direction indicated by is incident, the electrons in the metal vibrate, and the electrons concentrate on the vertex 13. As a result, FIG.
A large dipole (polarization) 21 is generated at the vertex 13 as shown in FIG. When the sample is brought close to the probe tip, an image dipole 22 of the dipole 21 is generated on the sample 25 side, and as a result of the interaction between the two dipoles 21 and 22, a strong near-field light 26 is generated between the probe tip 13 and the sample. . The light may be incident from the outside of the projection (arrow 16 in FIG. 1), or may be incident from the inside of the projection when the projection is formed of a light transmissive material (arrow 14 in FIG. 1). The material forming the projection is, for example, Si, SiO 2 , SiN, or the like. For example, gold, silver, aluminum, or the like is used for the metal film. The thickness of the metal film is several tens
It may be 0 nm or less, for example, 30 nm. The radius of curvature of the end of the metal film at the vertex 13 may be 100 nm or less, but is preferably smaller to achieve high resolution. For example, the radius of curvature is set to 20 nm. It is preferable that the wavelength of the light incident on the probe be set to the resonance point (plasmon resonance point) of the plasma oscillation of the electrons in the metal film. As an example, FIG. 3 shows the relationship between near-field light intensity and light wavelength calculated by approximating a metal film formed on the side surface of a protrusion to a metal film having a planar triangular shape. This value is FDTD
Law (Journal of Optical Society of America A, Vol.1
2, No. 9, p1974-1983, 1995, (Japanese name) Journal of Optical Society of America A). In this calculation, the material of the triangular film is gold, the film thickness = 30 nm, the radius of curvature of the tip = 25 nm, the vertex angle of the vertex =
The angle was set to 40 °, and it was assumed that this film was placed in the plane in the XY directions (the metal film was placed in the air). It is assumed that the wave source is placed at a position one wavelength away from the metal pattern in the Z direction, and that a plane wave is generated in the Z direction from the wave source. The size of the analysis area is 0.3 × in each of x, y, and z directions.
The boundary condition of the analysis region was a periodic boundary condition on a plane perpendicular to the x-axis and the y-axis, and an absorption boundary condition on a plane perpendicular to the z-axis. The distance between the wave source and the absorption boundary was one wavelength.
The number of meshes is 60 × 50 × 60 in each of x, y, and z directions,
Using a non-uniform mesh with a small gap near the vertex of the triangular membrane, the mesh gap near the vertex of the triangular membrane is 2.5 nm
And The time step size is 1 × 10 -18 seconds, the number of calculation repetitions is
15,000 times. The vertical axis represents the ratio between the near-field light intensity at the apex and the power density of the incident light. As described above, there is a resonance wavelength near 650 nm, and the near-field light intensity becomes maximum at that time. Although the above calculation assumes that the metal film is in the air, the metal film is actually formed on the surface of the projection, and the sample approaches the vicinity of the apex. As a result, it is considered that the actual resonance wavelength is slightly shifted from the above resonance wavelength. The above projections
It may be formed on the emission surface of a semiconductor laser such as a surface emitting laser. Light emitted from the semiconductor laser is scattered by the tip of the metal film at the apex, and strong near-field light is generated at the apex. By thus integrating the light source and the probe, it is not necessary to align the light source and the probe. The above projection may be formed on the emission surface of the resonator. Thereby, the light use efficiency is further improved.
【０００８】上記の金属パターンが形成された突起は、
球面レンズやホログラフィックレンズなどの集光素子の
端面に形成しても良い。焦点の位置が三角形の頂点にく
るようにすることにより、プローブに入射させる光を平
行光にすることが可能になる。したがって、プローブに
入射させる光の焦点の位置合わせが不要になる。[0008] The protrusion on which the metal pattern is formed is
It may be formed on the end face of a light-collecting element such as a spherical lens or a holographic lens. By setting the focal point at the apex of the triangle, it is possible to make the light incident on the probe parallel. Therefore, there is no need to position the focal point of the light incident on the probe.
【０００９】上記の金属パターンはフォトダイオードな
どの光検出器の受光面に形成しても良い。これにより、
検出器とプローブの位置合わせが不要になる。The above metal pattern may be formed on a light receiving surface of a photodetector such as a photodiode. This allows
Alignment between the detector and the probe is not required.
【００１０】上記の金属パターンが形成された突起は、
原子間力顕微鏡のカンチレバーの先に形成しても良い。
これにより原子間力像と光学像を同時に測定することが
可能になる。The projection on which the above metal pattern is formed is
It may be formed before the cantilever of an atomic force microscope.
This makes it possible to simultaneously measure the atomic force image and the optical image.
【００１１】上記の金属パターンが形成された突起51の
周辺に、図4のように、高さＨ１が突起の高さＨ2と等し
いパッド52を形成しても良い。これにより、突起51を試
料表面に近づけたとき、突起が破損する確立が低下す
る。また、パッドを形成することに換えて、突起の高さ
Ｈ１と同じ深さのくぼみを基板上に形成し、そのくぼみ
中に突起を形成しても良い。A pad 52 having a height H1 equal to the height H2 of the protrusion may be formed around the protrusion 51 on which the above-described metal pattern is formed, as shown in FIG. Thereby, when the protrusion 51 is brought closer to the sample surface, the probability of the breakage of the protrusion decreases. Instead of forming the pad, a depression having the same depth as the height H1 of the projection may be formed on the substrate, and the projection may be formed in the depression.
【００１２】図5に、金属膜が形成された突起601を原子
間力顕微鏡のカンチレバー603の先に形成したプローブ
を近接場光学顕微鏡に応用した例を示す。試料610は基
板611の上に置き、その表面に、カンチレバーの先に形
成された突起601を近づける。レーザー606から出射した
光はレンズ616によりコリメートされ、ビームスプリッ
タ605を通過後、対物レンズ604に入射する。光は対物レ
ンズにより集光され突起先端で収束する。プローブによ
り発生した近接場光は試料610と相互作用し、その結果
散乱光や発光などが発生する。この試料からの光は対物
レンズ604により集光され検出器607で検出されるか、も
しくは試料の反対側に置かれた対物レンズ612および検
出器613で検出される。試料はピエゾ素子608を使い水平
方向に走査させ像を得る。FIG. 5 shows an example in which a probe in which a projection 601 formed with a metal film is formed at the tip of a cantilever 603 of an atomic force microscope is applied to a near-field optical microscope. The sample 610 is placed on the substrate 611, and the protrusion 601 formed at the tip of the cantilever is brought close to the surface of the sample 610. Light emitted from the laser 606 is collimated by the lens 616, passes through the beam splitter 605, and enters the objective lens 604. Light is collected by the objective lens and converges at the tip of the projection. The near-field light generated by the probe interacts with the sample 610, and as a result, scattered light, light emission, and the like are generated. The light from the sample is collected by the objective lens 604 and detected by the detector 607, or detected by the objective lens 612 and the detector 613 placed on the opposite side of the sample. The sample is scanned in the horizontal direction using the piezo element 608 to obtain an image.
【００１３】プローブ先端と試料表面の間隔は数10 nm
以内にする必要があるが、その間隔ははプローブ先端と
試料表面の間に働く原子間力を測定することにより制御
する。すなわちプローブを数10 nm以内の振幅でピエゾ6
09を使い縦方向に振動させ、その振幅が一定になるよう
にプローブ先端と試料表面の間隔を制御する。振幅の変
化の測定は、レーザー606から出射した光とは別の光を
カンチレバーの上面602に当て、そこからの反射光をＰ
ＳＤ(Position Sensing Detector)で検出することによ
り行う。なお、振幅の変化の測定は、レーザー606から
出射した光のうち、カンチレバーの上面602で反射した
ものを、PSD 614で検出することにより行っても良い。The distance between the probe tip and the sample surface is several tens of nm
The distance is controlled by measuring the atomic force acting between the probe tip and the sample surface. That is, the probe is piezo 6
Vibration is performed in the vertical direction using 09, and the distance between the probe tip and the sample surface is controlled so that the amplitude is constant. To measure the change in the amplitude, light different from the light emitted from the laser 606 is applied to the upper surface 602 of the cantilever, and reflected light from the
This is performed by detecting with an SD (Position Sensing Detector). The measurement of the change in the amplitude may be performed by detecting, with the PSD 614, the light emitted from the laser 606, which is reflected on the upper surface 602 of the cantilever.
【００１４】入射した光の偏光方向と試料から発生する
光の偏光方向が異なっている場合は、偏光子615を用い
て、試料からの光を入射光から分離しても良い。When the polarization direction of the incident light is different from the polarization direction of the light generated from the sample, the light from the sample may be separated from the incident light by using a polarizer 615.
【００１５】入射した光の波長と試料から発生する光の
波長が異なっている場合は、波長フィルタまたは分光器
を用いて、試料からの光を入射光から分離しても良い。When the wavelength of the incident light is different from the wavelength of the light generated from the sample, the light from the sample may be separated from the incident light using a wavelength filter or a spectroscope.
【００１６】上記近接場プローブの光記録/再生装置へ
の応用例を図6に示す。近接場光プローブ702は対物レン
ズ、光源、検出器等を搭載した光ヘッド703に搭載さ
れ。その光ヘッドをディスク701に近づける。光ヘッド
はキャリッジアクチュエーター704を用いて、ディスク
の半径方向に動かされる。光ヘッド内部の光学系は図7
(b)のように構成する。光源には半導体レーザー708を用
い、出射光をコリメーターレンズ709、ビーム整形プリ
ズム710を用いて円形の平行ビームにする。このビーム
はビームスプリッタ712、ミラー715、対物レンズ707を
通過後、近接場光プローブ702に入射する。対物レンズ
の位置はアクチュエーター706を用いて調整される。ま
た、トラッキングのため近接場光プローブの位置を微調
整するためには、アクチュエーター704を用いる。プロ
ーブ702はサスペンション705に取り付けられていて、こ
のサスペンションの力によりディスク701に押し付けら
れる。プローブからの反射光（信号光）はビームスプリ
ッタ-712により入射光と分離され、検出器714に入射す
る。ここでプローブからの光の偏光方向が入射光の偏光
方向と異なっている場合、入射光と反射光を分離するた
めに、偏光子711、713を挿入しても良い。FIG. 6 shows an application example of the near-field probe to an optical recording / reproducing apparatus. The near-field optical probe 702 is mounted on an optical head 703 on which an objective lens, a light source, a detector and the like are mounted. The optical head is moved closer to the disk 701. The optical head is moved in the radial direction of the disk using the carriage actuator 704. Figure 7 shows the optical system inside the optical head.
The configuration is as shown in (b). A semiconductor laser 708 is used as a light source, and the emitted light is converted into a circular parallel beam using a collimator lens 709 and a beam shaping prism 710. This beam enters the near-field optical probe 702 after passing through the beam splitter 712, the mirror 715, and the objective lens 707. The position of the objective lens is adjusted using the actuator 706. An actuator 704 is used to finely adjust the position of the near-field optical probe for tracking. The probe 702 is attached to a suspension 705, and is pressed against the disk 701 by the force of the suspension. The reflected light (signal light) from the probe is separated from the incident light by the beam splitter-712 and enters the detector 714. Here, when the polarization direction of the light from the probe is different from the polarization direction of the incident light, polarizers 711 and 713 may be inserted to separate the incident light and the reflected light.
【００１７】[0017]
【発明の効果】本発明により、光利用効率が高く、凹凸
のある試料表面に対しても使用可能で、かつ大量製産可
能な近接場光プローブの実現が可能になる。According to the present invention, it is possible to realize a near-field optical probe which has high light utilization efficiency, can be used even on a sample surface having irregularities, and can be mass-produced.
【図１】本発明の近接場光プローブを示す斜視図。FIG. 1 is a perspective view showing a near-field optical probe of the present invention.
【図2】プローブ先端に発生するダイポールを示す図。FIG. 2 is a diagram showing a dipole generated at the tip of a probe.
【図3】近接場光強度と光波長の関係。FIG. 3 shows the relationship between near-field light intensity and light wavelength.
【図4】突起の周辺にパッドが形成されたプローブの斜
視図。FIG. 4 is a perspective view of a probe in which a pad is formed around a protrusion.
【図5】近接場光学顕微鏡への応用例。FIG. 5 shows an example of application to a near-field optical microscope.
【図6】近接場光記録/再生への応用例。FIG. 6 shows an example of application to near-field optical recording / reproduction.
11 全面が金属で覆われた面 12 頂点以外が金属で覆われた面 13 頂点 14 突起の内側から光を入射させる場合の光の入射方向 15 偏光方向 16 突起の外側から光を入射させる場合の光の入射方向 21 金属膜先端に発生するダイポール 22 試料中に発生するイメージダイポール 23 金属膜 24 突起 25 試料 26 近接場光 51 金属膜が形成された突起 52 パッド 601 金属膜が形成された突起 602 カンチレバーの上面 603 カンチレバー 604 対物レンズ 605 ビームスプリッター 606 半導体レーザー 607 光検出器 608 走査用ピエゾ 609 カンチレバー振動用ピエゾ 610 試料 611 基板 612 集光レンズ 613 光検出器 614 PSD 615 偏光子 616 コリメートレンズ 701 ディスク 702 近接場光プローブ 703 光ヘッド 704 キャリッジアクチュエーター 705 サスペンション 706 アクチュエーター 707 対物レンズ 708 半導体レーザー 709 コリメートレンズ 710 ビーム整形プリズム 711 偏光子 712 ビームスプリッタ 713 偏光子 714 光検出器 715 ミラー。 11 Surface covered entirely with metal 12 Surface covered with metal other than vertices 13 Vertex 14 Light incident direction when light is incident from inside projection 15 Polarization direction 16 When light is incident from outside projection Light incident direction 21 Dipole generated at the tip of metal film 22 Image dipole generated in sample 23 Metal film 24 Projection 25 Sample 26 Near-field light 51 Projection with metal film 52 Pad 601 Projection with metal film 602 Top surface of cantilever 603 Cantilever 604 Objective lens 605 Beam splitter 606 Semiconductor laser 607 Photodetector 608 Scanning piezo 609 Piezoelectric for cantilever oscillation 610 Sample 611 Substrate 612 Condenser lens 613 Photodetector 614 PSD 615 Polarizer 616 Collimating lens 701 Disk 702 Near-field optical probe 703 Optical head 704 Carriage actuator 705 Suspension 706 Actuator 707 Objective lens 7 08 Semiconductor laser 709 Collimating lens 710 Beam shaping prism 711 Polarizer 712 Beam splitter 713 Polarizer 714 Photodetector 715 Mirror.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｇ１２Ｂ 21/06 Ｇ１２Ｂ 1/00 ６０１Ｃ ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) G12B 21/06 G12B 1/00 601C
Claims (10)
面のうちの１面が金属の膜で覆われたことを特徴とする
近接場光プローブ1. A near-field optical probe comprising a projection in the shape of a polygonal pyramid, one of its side surfaces being covered with a metal film.
ていることを特徴とする請求項1記載の近接場光プロー
ブ2. The near-field optical probe according to claim 1, wherein said projection is made of a material having a light transmitting property.
形成されたことを特徴とする請求項1又は２記載の近接
場光プローブ3. The near-field optical probe according to claim 1, wherein said projection is formed on an emission surface of a semiconductor laser.
れたことを特徴とする請求項1又は２記載の近接場光プ
ローブ4. The near-field optical probe according to claim 1, wherein said projection is formed on an emission surface of an optical resonator.
ィックレンズなどの集光素子の端面に形成されたことを
特徴とする請求項1又は２記載の近接場光プローブ5. The near-field optical probe according to claim 1, wherein the projection is formed on an end face of a light-collecting element such as a hemispherical lens or a holographic lens.
検出器の受光面に形成されたことを特徴とする請求項1
又は2記載の近接場光プローブ6. The method according to claim 1, wherein said projection is formed on a light receiving surface of a photodetector such as a photodiode.
Or the near-field optical probe described in 2.
バーの先に形成されたことを特徴とする請求項1又は2記
載の近接場光プローブ7. The near-field optical probe according to claim 1, wherein the projection is formed at a tip of a cantilever of an atomic force microscope.
さをもつパッドが形成されたことを特徴とする請求項1
乃至7何れかに記載の近接場光プローブ8. A pad having a height equal to the height of the projection is formed around the projection.
The near-field optical probe according to any one of to 7
らなり、その側面のうちの１面が金属の膜で覆われたプ
ローブを用いたことを特徴とする近接場光学顕微鏡。9. A near-field optical microscope comprising a probe having light-transmitting protrusions in the shape of a polygonal pyramid, one of the side surfaces of which is covered with a metal film.
からなり、その側面のうちの１面が金属の膜で覆われた
プローブを用いたことを特徴とする光記録／再生装置。10. An optical recording / reproducing apparatus comprising a probe having light-transmitting protrusions in the shape of a polygonal pyramid, one of the side surfaces of which is covered with a metal film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001016500A JP2002221477A (en) | 2001-01-25 | 2001-01-25 | Proximity field optical probe, proximity field optical microscope using the same and optical recording / reproducing apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001016500A JP2002221477A (en) | 2001-01-25 | 2001-01-25 | Proximity field optical probe, proximity field optical microscope using the same and optical recording / reproducing apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002221477A true JP2002221477A (en) | 2002-08-09 |
Family
ID=18882860
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001016500A Pending JP2002221477A (en) | 2001-01-25 | 2001-01-25 | Proximity field optical probe, proximity field optical microscope using the same and optical recording / reproducing apparatus |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006329968A (en) * | 2005-04-26 | 2006-12-07 | Seiko Instruments Inc | Method for manufacturing proximity field light emitting element |
| JP2011090001A (en) * | 2005-04-26 | 2011-05-06 | Seiko Instruments Inc | Method of manufacturing near-field light generation element |
| JP2011242308A (en) * | 2010-05-19 | 2011-12-01 | Gifu Univ | Near-field light probe |
| JP2012037527A (en) * | 2006-01-16 | 2012-02-23 | Seiko Instruments Inc | Method for manufacturing near-field light generating element |
| KR20130057761A (en) * | 2011-11-24 | 2013-06-03 | 삼성전자주식회사 | Holography device, three dimensional display holography display including the holography device and method of processing holography image |
-
2001
- 2001-01-25 JP JP2001016500A patent/JP2002221477A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006329968A (en) * | 2005-04-26 | 2006-12-07 | Seiko Instruments Inc | Method for manufacturing proximity field light emitting element |
| JP2011090001A (en) * | 2005-04-26 | 2011-05-06 | Seiko Instruments Inc | Method of manufacturing near-field light generation element |
| JP2012037527A (en) * | 2006-01-16 | 2012-02-23 | Seiko Instruments Inc | Method for manufacturing near-field light generating element |
| JP2011242308A (en) * | 2010-05-19 | 2011-12-01 | Gifu Univ | Near-field light probe |
| KR20130057761A (en) * | 2011-11-24 | 2013-06-03 | 삼성전자주식회사 | Holography device, three dimensional display holography display including the holography device and method of processing holography image |
| KR101859663B1 (en) | 2011-11-24 | 2018-06-29 | 삼성전자주식회사 | Holography device, three dimensional display holography display including the holography device and method of processing holography image |
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