JP2010266452A - Scanning optical near-field microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scanning optical near-field microscope capable of fast scanning and is capable of coping with respect to samples with large dimensions and weight. <P>SOLUTION: In the scanning optical near-field microscope which includes a means for installing a prove 3 and a probe tip 2 thereof that approaches a sample 1; a means for forcing to scan the sample 1 and the probe tip 2 of the prove, relatively substantially parallel to a surface of the sample 1; a light-incident means for making the light from a light source 16 condense on the probe tip 2; and a light-condensing optical means for condensing the light emitted between the probe tip 2 and the sample 1, in order to detect by a light-detecting means 15 for creating an image of light flux from the lighting optical means; an aperture 14 is prepared at a substantially conjugate position, with the position of the probe tip of the light-condensing optical means to remove unwanted light and a scanning optical system 11 is incorporated into the light-condensing optical means, resulting a possible light focusing following the change in the position of the probe 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a scanning near-field optical microscope, and in particular, scans a probe close to a sample relative to the sample, concentrates the light on the sample and the probe tip in the vicinity thereof, and emits light from the vicinity of the probe tip. The present invention relates to a scanning near-field optical microscope that measures the optical characteristics of a sample by detecting.

  A scanning near-field optical microscope (hereinafter referred to as SNOM: Scanning Near-Field Optical Microscope) is a probe having an opening at the tip having a diameter smaller than the wavelength of light, or a sharpened probe having a curvature smaller than the wavelength of light. This is a device for measuring optical information of a micro area of a sample by scanning a probe having a non-opening tip with a sample in the vicinity of the sample.

  This scanning near-field optical microscope can obtain a resolution of the above-described aperture diameter or radius of curvature of the tip (up to several tens of nanometers) compared to an optical microscope whose resolution is limited by the diffraction limit. Therefore, it is expected in the future as a device capable of observation and measurement with higher resolution.

  SNOMs can be broadly classified according to the type of probe, as described above, into an aperture type having an aperture and a non-aperture scattering type. The difference is as follows. The aperture type irradiates the sample with light through the aperture, or detects light from the sample through the aperture to obtain optical information of the sample. On the other hand, the scattering type scatters a local electric field generated on the sample surface by incident light from the outside with a sharpened probe tip and detects the scattered light to obtain optical information of the sample.

  Among these types, other than the type that detects light from the sample through the aperture with an aperture type probe using an optical fiber, etc., light generated when light is irradiated to the sample with the probe tip close by some means Is condensed by a condensing optical system composed of a normal optical system. The operation will be described below with reference to FIG.

  FIG. 5 is a scattering SNOM whose probe tip is optically opaque. In order to maintain a constant distance between the probe tip 2 and the surface of the sample 1 that is sufficiently close, it is common to use the principle of an atomic force microscope (hereinafter AFM). This utilizes the fact that the probe 3 bends due to the atomic force acting between the probe tip 2 and the sample 1 when the probe tip 2 approaches the sample 1, so that the probe 3 to the sample always have a constant deflection amount. This is realized by driving the actuator 1 in the vertical direction by driving the actuator 4 for the probe or the actuator 26 attached to the sample stage. The measurement of the deflection of the probe 3 is performed by, for example, the detector 25 using the optical lever principle.

  In addition, the vibration is attached to the probe 3 and the probe 3 is vibrated up and down or in a direction substantially parallel to the surface of the sample 1, and the amplitude of the probe tip 2 changes with the distance from the surface of the sample 1. Control can also be performed.

  As described above, scanning is performed in a state where the probe tip 2 is close to the sample 1. For the scanning, the controller 26 operates the actuator 26 attached to the sample stage to perform raster scanning in a direction substantially parallel to the surface of the sample 1. Do.

  Light irradiation to the probe tip 2 is performed by irradiating light from the light source 16 such as laser light to the vicinity of the probe tip 2 by the irradiation optical system 23.

  Scattered light from the vicinity of the probe tip 2 caused by light irradiation is condensed using the condenser lens 7 and the imaging lens 8. By placing the pinhole 14 at the condensing position, light from other than the vicinity of the probe tip 2 is cut to reduce optical noise from the surroundings. The light that has passed through the pinhole 14 is converted into an electric signal by the photomultiplier tube 15, processed by the computer 17, and then displayed on the monitor 18 as a measurement result. When substances of different materials are mixed in the sample 1, the amount of scattered light varies, so that the presence can be displayed in the order of the diameter of the probe tip.

  As another type of SNOM, there is a type in which a minute opening is opened at the probe tip 2 and the sample 1 is irradiated with light from here, and detection of light from the sample 1 is also performed in the sample 1 as in the above example. In addition to the reflective type that detects reflected light from the surface, there are types such as a transmissive type that detects light transmitted through the sample 1.

  Usually, the substantial size of the probe tip 2 is sufficiently smaller than the wavelength of light to be used, so that it can be regarded as a point light source, but the amount of scattered light is small accordingly. Accordingly, if there is scattered light from other parts of the sample, the quality of measurement such as the S / N ratio is degraded. Therefore, it is possible to block unnecessary scattered light by placing a small opening such as a pinhole 14 at a position conjugate with the probe tip 2 so that only scattered light from the probe tip 2 that can be regarded as a point light source can be detected. Generally done.

  The conventional SNOM as described above has the following problems.

  That is, since the pinhole position is usually fixed, the scanning is performed by moving the sample. However, in the case of a sample stage driven by the actuator 26, it is difficult to place a sample having a large size and weight.

  Even if the sample can be placed, it is difficult to scan the sample stage at a high speed if the size and weight of the sample itself are large.

  The present invention has been made in view of such problems of the prior art, and the object thereof is to place a sample having a large size and weight, and to scan such a sample at high speed. A scanning near-field optical microscope is provided.

  In order to solve the above problems, the present invention uses a method in which only the probe is moved for scanning, or only the direction in which the scanning speed may be slow is used even if the sample is moved.

  Further, in order to scan the probe, the apparatus is configured such that the opening for cutting unnecessary scattered light from other than the vicinity of the probe tip is always in a conjugate position with the probe tip position.

Therefore, in the present invention,
A probe; means for placing the probe tip close to the sample; means for scanning the sample and the probe tip relatively parallel to the sample surface; a light source; and light from the light source Light condensing means for concentrating the light at the tip of the probe, and condensing optical means for condensing the light generated between the tip of the probe and the sample by the light incident means. In a scanning near-field optical microscope that detects and images the luminous flux of the
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
In addition, the condensing optical means includes a scanning optical system, and is configured to be able to collect light following a change in the position of the probe.

Alternatively, a probe, means for placing the probe tip close to the sample, means for scanning the sample and the probe tip relatively parallel to the sample surface, a light source, and the light source Light condensing means for concentrating the light at the tip of the probe, and condensing optical means for condensing the light generated between the tip of the probe and the sample by the light incident means. In the scanning near-field optical microscope that detects and images the light flux from the means by the light detection means,
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
The scanning near-field optical microscope according to claim 1, wherein the opening is a slit, and the direction of the slit is along the scanning direction of the probe.

Alternatively, a probe, means for placing the probe tip close to the sample, means for scanning the sample and the probe tip relatively parallel to the sample surface, a light source, and the light source Light condensing means for concentrating the light at the tip of the probe, and condensing optical means for condensing the light generated between the tip of the probe and the sample by the light incident means. In the scanning near-field optical microscope that detects and images the light flux from the means by the light detection means,
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
2. The scanning near-field optical microscope according to claim 1, wherein the opening comprises a plurality of openings.
The above-described object is achieved by adopting the configuration described above.

  As is apparent from the above description, according to the present invention, it is possible to provide a scanning near-field optical microscope that can cope with a sample having a large size and weight and can be scanned at high speed.

It is a figure which shows the structure of the scanning near-field optical microscope of 1st Example of this invention. It is a figure which shows the structure of the scanning near-field optical microscope of 2nd Example of this invention. It is a figure which shows the structure of the scanning near-field optical microscope of 3rd Example of this invention. It is a figure which shows the structure of the scanning near-field optical microscope of 4th Example of this invention, and the scanning near-field optical microscope of the deformation | transformation. It is a figure which shows the structure of the conventional scattering type scanning near-field optical microscope.

  The features of the scanning near-field optical microscope of the present invention will be described below, and then the embodiments will be described with reference to the drawings. In the description relating to each drawing, the same reference numerals indicate elements having the same function. Also, elements that are considered to be essentially unrelated to the description of the present invention, such as the mechanism 25 for measuring the distance between the probe 3 and the sample 1, are the same as in the description of the conventional example, and the details are omitted. Hereinafter, a description will be given based on examples.

(First embodiment)
FIG. 1 shows the first embodiment. The first embodiment is an example of a scattering type SNOM incorporating a scanning optical system by a galvano scanner. The SNOM scan is performed by moving the probe 3 in a direction substantially parallel to the surface of the sample 1 on the sample stage 5.

  In order to collect the incident light on the probe tip 2, the following is performed. That is, the light from the laser light source 16 is reflected by the half mirror 12, deflected by the galvano scanner 11, and collected at the probe tip 2 placed near the sample 1 by the objective lens 7 through the pupil projection lens 10 and the half mirror 9. To be lighted.

  The angle of the galvano scanner 11 is controlled so that incident light is focused on the moving probe tip 2, and this is because the galvano scanner 11 moves in synchronization with the drive signal of the actuator 4 that moves the probe 3. This is because it is controlled by the controller 6.

  As a method for controlling the position of the incident light, for example, the position of the probe tip 2 is measured by the CCD camera 19 for observing the sample 1 and the galvano scanner 11 is controlled by feeding back the information.

  Scattered light from the vicinity of the probe tip 2 whose light amount or the like has changed due to the optical characteristics of the sample 1 is collected again by the objective lens 7, passes through the half mirror 12 along the reverse optical path, and then the detection lens 13 and the pinhole 14. The pin hole 14 that is a minute aperture is substantially conjugated with the image plane of the objective lens 7, so that the aperture diameter of the pin hole 14 is set to an appropriate size. Thus, unnecessary scattered light from other than the vicinity of the probe tip 2 can be cut.

  The detection signal of the photomultiplier tube 15 is processed by the computer 17 and displayed on the monitor 18 as measurement data.

  Thus, since the SNOM of the present embodiment scans the probe 3, the sample can be observed and measured regardless of the size and weight of the sample. In addition, since the scanning optical system is arranged, it is possible to always irradiate the probe tip 2 with incident light (illumination light) while scanning the probe 3 at high speed. As a result, sample observation or measurement by high-speed scanning can be realized. Further, since the pinhole position is always constant by the scanning optical system, the scattered light can be detected as in the conventional case. Further, only the scattered light from the vicinity of the probe tip 2 can be detected by this pinhole, and measurement with a high S / N ratio is possible by cutting off the light from other locations.

  In the configuration of this embodiment, the incident optical system (from the light source 16 to the objective lens 7) and the condensing optical system (from the objective lens 7 to the photomultiplier tube 15) have a common optical system (from the objective lens 7). Half mirror 12). Therefore, for example, if the incident optical system is used to adjust the light from the light source to the tip of the probe, the focusing optical system can be adjusted only by adjusting the positions of the pinhole and the photomultiplier tube. This can be adjusted very easily as compared with the conventional configuration in which the incident optical system and the condensing optical system are separated.

  In addition, since the configurations of the incident optical system and the condensing optical system of the present embodiment are the same as the scanning system of the laser scanning microscope, the laser microscope can be made exclusively of the SNOM by measuring with the probe 3 removed. Can do. And after measuring with a laser microscope, the usage which measures a finer part by SNOM with a sample as it is is possible.

  In this embodiment, for clarity of explanation, only one galvano scanner 11 is shown and the scanning direction of the probe 3 is shown only in one direction indicated by an arrow, but by using two scanners, Of course, the probe 3 can be scanned in a two-dimensional direction. Further, a polygon mirror, an AOD (acoustic light deflection element), or the like can be used instead of the galvano scanner.

(Second embodiment)
FIG. 2 shows a second embodiment. The second embodiment is a scattering type SNOM in which a slit 20 is placed at the image plane position of a condensing optical system, and has a configuration in which a spectroscope 21 is installed to perform spectroscopic measurement. The probe 3 is scanned in a direction along the slit 20.

  The scanning is performed by moving the probe 3 in the main scanning direction where the scanning speed is high and scanning the sample 1 in the sub-scanning direction substantially orthogonal thereto. In general, scanning in the sub-scanning direction has a periodic speed of about several tens to hundreds of hundreds of scanning in the main scanning direction, so that the scanning speed can be increased compared to scanning by moving the sample 1 in both directions. It becomes.

  As the incident light, an incident optical system adjusted to illuminate the extent to cover the measurement region is used. This comprises a light source 16 and an irradiation lens 23, and the irradiation lens 23 is selected so that the spot on the sample 1 is about the scanning region of the probe 3.

  As the light source 16, a halogen lamp, a mercury lamp, a combination of lasers having a plurality of wavelengths, or the like according to the type of spectroscopy to be performed, or a monochromatic light source such as a laser is used in the case of Raman spectroscopy.

  The light incident on the sample 1 becomes scattered light due to the presence of the probe tip 2. This scattered light is collected by the objective lens 7, passes through the slit 20 placed on the imaging surface by the imaging lens 8, and is dispersed by the spectroscope 21. The split light is irradiated onto the two-dimensional detector 22 as indicated by reference numeral 221 and detected as spectral data.

  In the case of Raman spectroscopy, since the light to be detected is close to the wavelength of the incident light and the intensity is very weak, it is desirable to use a filter that cuts off the incident light between the two-dimensional detector 22.

  A feature of the present embodiment is that since the slit 20 is along the scanning direction of the probe 3, spectral data obtained by one scanning of the probe 3 can be detected as it is on the two-dimensional detector 22.

  Here, the two-dimensional detector 22 may be an image sensor such as a CCD or CMOS, or a combination of MCP (Multi Channel Plate). The S / N ratio can be increased by cutting unnecessary scattered light other than the scattered light from the probe tip 2 using the slit 20 and the pixels of the two-dimensional detector.

  The detected spectral data is processed by the computer 17 and displayed on the monitor 18.

  Here, an example in which the sample 1 is scanned in the sub-scanning direction has been described, but the same effect can be obtained by scanning the slit 20 instead of scanning the sample 1. In this case, since the positional relationship between the slit 20 and the spectroscope 21 slightly changes, the position of the irradiation light 221 on the two-dimensional detector 22 is affected, but this influence is corrected by processing on the computer 17. It is possible to apply.

  By scanning the slit 20, measurement can be performed even if the size and weight of the sample 1 are considerably increased.

  In FIG. 2, the configuration allows spectroscopic analysis, but it is of course possible to perform normal measurement by removing the spectroscope 20 and placing a line sensor on the slit 20.

(Third embodiment)
FIG. 3 shows a third embodiment. The third embodiment is a scattering-type SNOM that scans the probe 3, and a spatial light modulator such as a two-dimensional liquid crystal light valve is placed on the imaging surface of the condensing optical means.

  Incident light is incident on the liquid crystal light valve 24 by the objective lens 7 and the imaging lens 8, and the scattered light from the vicinity of the probe tip 2 is incident on the liquid crystal light valve 24 by the light source 16 and the irradiation lens 23. The liquid crystal light valve 24 can change the transmittance of an arbitrary pixel. In the present embodiment, control is performed so as to synchronize with the movement of the probe tip 2 by increasing the transmittance of the pixel at the position conjugate with the probe tip 2 and lowering the transmittance of the other pixels. It is as if the opening is always moving in a conjugate position with the probe tip 2 in synchronization with the movement of the probe 3. This control is performed by controlling the controller 6 of the actuator 4 that drives the probe 3.

  The light transmitted through the liquid crystal light valve 24 is detected by the photomultiplier tube 15, and an image processed by the computer 17 is displayed on the monitor 18.

  In general, the size of the minute aperture for removing unnecessary scattered light is about the spot diameter (Airy disk diameter) formed by the objective lens 7 and the imaging lens 8, but the size is actually in consideration of the detected light amount. It may be necessary to change. Further, when the objective lens 7 is replaced with another objective lens, the size of the spot formed on the liquid crystal light valve 24 changes depending on the difference in specifications.

  In order to cope with these, the number of pixels of the liquid crystal light valve 24 that increases the transmittance is set to a required size by combining a plurality of pixels from one pixel accordingly, for example, using 2 × 2 pixels. By making it possible to deal with up to the number of, it can be more general. In this case, as the pixel size is smaller, various correspondences are possible. In this case, since the probe tip 2 can be regarded as a point light source, it is desirable for noise removal that the size of one pixel is at least equal to or smaller than the Airy disk diameter by the condensing optical system.

(Fourth embodiment)
FIG. 4 shows a fourth embodiment. The fourth embodiment is a SNOM that scans the probe 3 and uses a two-dimensional image sensor 22 as a detecting means. FIG. 4A is an aperture type SNOM using the cantilever probe 3 and is an example in which an evanescent wave is generated on the sample 1 by using a total reflection prism 27 in the incident optical system.

  Light from the opening of the probe tip 2 generated by the incident light forms a spot on the two-dimensional detector 22 by the objective lens 7 and the imaging lens 8. As the two-dimensional detector 22, a CMOS type image pickup device, a combination of MCP and CCD, or the like is used.

  The two-dimensional detector 22 detects pixels corresponding to the opening of the probe tip 2. For this reason, for example, in a combination of MCP and CCD, each of the MCPs is controlled by the controller 6 of the actuator 4 that drives the probe 3. The trigger to the cell is controlled, and only the cell corresponding to the opening position of the probe tip 2 multiplies light. When a CMOS type image sensor is used, the same effect can be obtained by applying a mask to signals from other pixels so that signals from pixels corresponding to the position of the probe tip 2 are detected. Can hold.

  As in the third embodiment, it is better to change the size of the opening for removing unnecessary light depending on the use of the imaging optical system or the like. In this embodiment as well, it corresponds to the opening position of the probe tip 2. The number of cells or pixels can be changed through the computer 17.

  The above principle is not limited to SNOM using a cantilever probe, and can be used as a configuration using an aperture probe 3 using an optical fiber 28 as shown in FIG. 4B, for example. In this example, it is a transmission type SNOM that emits light from the probe tip 2 and detects through the sample 1, and other types can be applied as long as the type detects light outside the probe tip 2 as described above. Is possible.

  As described above, each configuration of the embodiment of the present invention in the first to fourth examples can be variously modified and changed. As long as the optical element used in each embodiment has a function mentioned in the embodiment, another element can be substituted.

  Further, although the transmission type, the reflection type, and the like are given as the incident optical means, these are not unique to each embodiment, and can be interchanged with each other. For example, in the first embodiment, the incident optical means irradiates the probe tip 2 through the scanning optical system. As a detection method, as mentioned in the first embodiment, the method of determining the position from the image of the CCD for optical observation can be used in the second embodiment and below.

  The above scanning near-field optical microscope of the present invention can be configured as follows, for example.

[1] a probe, means for installing the tip of the probe close to the sample, means for causing the sample and the probe tip to scan relatively parallel to the sample surface, a light source, and the light source Light condensing means for concentrating light from the tip of the probe and condensing optical means for condensing light generated between the tip of the probe and the sample by the light incident means. In the scanning near-field optical microscope that detects and images the light flux from the optical means by the light detection means,
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
In addition, the condensing optical means includes a scanning optical system, and is configured to be able to collect light following a change in the position of the probe.

    [2] The scanning near-field optical microscope as described in 1 above, wherein the light incident means shares part of the condensing optical means.

    [3] The scanning near-field optical microscope as described in 1 or 2 above, wherein the scanning optical system performs scanning by deflecting a light beam at a substantially pupil position of the condensing optical means.

    [4] The scanning near-field optical microscope as described in 1 or 2 above, wherein the scanning optical system performs scanning by scanning an opening for removing the unnecessary light.

[5] A probe, means for placing the probe tip near the sample, means for scanning the sample and the probe tip relatively parallel to the sample surface, a light source, and the light source Light condensing means for concentrating light from the tip of the probe and condensing optical means for condensing light generated between the tip of the probe and the sample by the light incident means. In the scanning near-field optical microscope that detects and images the light flux from the optical means by the light detection means,
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
Scanning near-field optical microscope characterized in that the opening is a slit and the direction of the slit is along the scanning direction of the probe. [6] The sample and the probe tip are relatively positioned relative to the sample surface. 6. The scanning near field according to claim 5, wherein the scanning is a raster scan, the probe is scanned in one direction, and the sample is scanned in a direction substantially perpendicular to the probe. Optical microscope.

    [7] The scanning near-field optical microscope as described in 5 or 6 above, wherein the light detecting means includes a spectroscopic means.

    [8] The scanning near-field optical microscope as described in [7], wherein the spectroscopic means includes a spectroscope and a two-dimensional sensor.

[9] A probe, means for placing the probe tip near the sample, means for scanning the sample and the probe tip relatively parallel to the sample surface, a light source, and the light source Light condensing means for concentrating light from the tip of the probe and condensing optical means for condensing light generated between the tip of the probe and the sample by the light incident means. In the scanning near-field optical microscope that detects and images the light flux from the optical means by the light detection means,
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
2. The scanning near-field optical microscope according to claim 1, wherein the opening comprises a plurality of openings.

    [10] The scanning near-field optical microscope as described in 9 above, wherein the plurality of apertures are formed of an aperture array.

    [11] The scanning near-field optical microscope as described in 9 or 10 above, wherein the aperture array comprises an array of spatial light modulators.

    [12] The scanning near-field optical microscope as described in 9 or 10 above, wherein the aperture array comprises a two-dimensional image sensor.

    [13] The scanning near-field optical microscope as described in any one of 9 to 12 above, wherein the size of the opening is a size that fits within an Airy disc diameter determined by the condensing optical means.

  As is apparent from the above description, according to the present invention, it is possible to provide a scanning near-field optical microscope that can cope with a sample having a large size and weight and can be scanned at high speed.

DESCRIPTION OF SYMBOLS 1 ... Sample 2 ... Probe tip 3 ... Probe 4 ... Probe actuator 5 ... Sample stand 6 ... Controller 7 ... Condensing lens 8 ... Imaging lens 9 ... Half mirror 10 ... Pupil projection lens 11 ... Galvano scanner 12 ... Half mirror 14 ... Pinhole 15 ... Photomultiplier 16 ... Light source 17 ... Computer 18 ... Monitor 19 ... CCD camera 20 ... Slit 21 ... Spectrometer 22 ... Two-dimensional detector 23 ... Irradiation optical system (irradiation lens)
24 ... Liquid crystal light valve 25 ... Detector 26 ... Sample stage actuator 27 ... Total reflection prism 28 ... Optical fiber 221 ... Irradiation light

Claims (9)

A probe; means for placing the probe tip close to the sample; means for scanning the sample and the probe tip relatively parallel to the sample surface; a light source; and light from the light source Light condensing means for concentrating the light at the tip of the probe, and condensing optical means for condensing the light generated between the tip of the probe and the sample by the light incident means. In a scanning near-field optical microscope that detects and images the luminous flux of the
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
The scanning near-field optical microscope according to claim 1, wherein the opening is a slit, and the direction of the slit is along the scanning direction of the probe. In the means for scanning the sample and the tip of the probe relatively in parallel with the sample surface, the scanning is raster scanning, the probe scans in one direction, and the sample is in a direction substantially perpendicular to the probe. The scanning near-field optical microscope according to claim 1, wherein scanning is performed. 3. The scanning near-field optical microscope according to claim 1, wherein the light detecting means includes a spectroscopic means. 4. The scanning near-field optical microscope according to claim 3, wherein the spectroscopic means includes a spectroscope and a two-dimensional sensor. A probe; means for placing the probe tip close to the sample; means for scanning the sample and the probe tip relatively parallel to the sample surface; a light source; and light from the light source Light condensing means for concentrating the light at the tip of the probe, and condensing optical means for condensing the light generated between the tip of the probe and the sample by the light incident means. In a scanning near-field optical microscope that detects and images the luminous flux of the
Furthermore, it has an opening for removing unnecessary light at a position substantially conjugate with the probe tip position by the condensing optical means,
2. The scanning near-field optical microscope according to claim 1, wherein the opening comprises a plurality of openings. 6. The scanning near-field optical microscope according to claim 5, wherein the plurality of apertures comprise an aperture array. 7. The scanning near-field optical microscope according to claim 6, wherein the aperture array comprises an array of spatial light modulators. The scanning near-field optical microscope according to claim 6, wherein the aperture array includes a two-dimensional image sensor. 9. The scanning near-field optical microscope according to claim 5, wherein the size of the opening is a size that can be accommodated in an Airy disk diameter determined by the condensing optical means.

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