JP2007219239A - Laser scanning type confocal microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser scanning type confocal microscope for improving resolution of height measurement and obtaining a confocal image having superior contrast. <P>SOLUTION: There are arranged respectively a shutter 24 on a reflection optical path of a second BS 16 that divides the optical path of a laser beam from a light source 1, a focusing lens 22 for which the pupil position is arranged at the pupil position of an objective lens 7 and at the position conjugate with an XY optical deflection unit 3, and a reference mirror 23 arranged at the focal position of the focusing lens 22. While the shutter 24 is opened the reflected light of the light scanned on the reference mirror 23 is introduced to a detector 11 side through an optical path similar to the reflected light of a specimen 8, wherein the respective reflected light beams interfere with each other, to detect the interference pattern by the detector 11 through a pinhole 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser scanning confocal microscope capable of micro three-dimensional measurement of a sample surface.

  2. Description of the Related Art Conventionally, a laser scanning confocal microscope is known as a technique for acquiring height information of a sample surface and performing minute three-dimensional measurement. This laser scanning confocal microscope uses the light from the light source as a spot to scan the sample surface two-dimensionally, and only the light reflected from the sample surface that has passed through the confocal pinhole is detected by the photodetector. Then, it is converted into an electric signal to obtain three-dimensional information on the sample surface.

  FIG. 5 shows a schematic configuration of a general laser scanning confocal microscope. A light beam emitted from a laser light source 101 passes through a beam splitter (PBS) 102 and then enters a two-dimensional scanning unit 103. The two-dimensional scanning unit 103 scans and outputs the light beam two-dimensionally. The two-dimensionally scanned light beam is guided to the objective lens 107. The two-dimensional scanning unit 103 is disposed at a position conjugate with the pupil of the objective lens 107, and the light beam incident on the pupil of the objective lens 107 is emitted as convergent light and scans on the focal plane of the sample 108. The light beam at this time is converted from linearly polarized light to circularly polarized light by the λ / 4 plate 104.

  The light reflected from the surface of the sample 108 is again guided from the objective lens 107 to the λ / 4 plate 104, where it is converted into linearly polarized light, and then introduced into the beam splitter 102 via the two-dimensional scanning means 103. The light is reflected by the beam splitter 102 and condensed on the pinhole 110 by the imaging lens 109. The reflected light collected on the pinhole 110 is cut by the pinhole 110 from light other than the focal point of the sample 108, and only the passing light is detected by the detector 111, guided to the controller 112, and sent to the monitor 115. Is displayed.

  In this case, the objective lens 107 can be moved in the optical axis direction (Z direction) by a Z stage (not shown). The two-dimensional scanning unit 103 and the Z stage (not shown) are controlled by the controller 112.

  Here, the focusing position by the objective lens 107 is at a position optically conjugate with the pinhole 110. For this reason, the light from the surface of the sample 108 that is in focus on the surface of the sample 108 passes through the pinhole 110, and the light from the surface of the sample 108 that is out of focus hardly passes through the pinhole 110. Only the light that has passed through is detected by the detector 111, and a signal corresponding to the intensity of the detected light is guided to the controller 112. Accordingly, the relationship between the relative position of the objective lens 107 and the sample 108 and the output of the detector 111 at this time is as follows. That is, when the sample 108 is at the condensing position of the objective lens 107, the output of the detector 111 is maximized. Then, as the relative position between the objective lens 107 and the sample 108 increases from this position, the output of the detector 111 rapidly decreases.

  As a result, if the two-dimensional scanning means 103 two-dimensionally scans the focal point on the surface of the sample 108 and images the output from the detector 111 in synchronism with the scanning by the two-dimensional scanning means 103, the presence of the sample Only a specific height is imaged, and an image (confocal image) obtained by optically slicing the sample 108 is obtained. Also, from this state, while moving the objective lens 107 in the optical axis direction, at each position, the two-dimensional scanning means 103 scans to obtain a confocal image, and at each point on the sample 108 surface, the detector 111 By detecting the position of the Z stage at which the output is maximized, the height information of the sample 108 can be obtained.

  By the way, as shown in FIG. 6, the optical resolution of the height information acquired in this way is the relative distance between the objective lens 107 and the sample 108, that is, the movement distance of the objective lens 107 in the optical axis direction and the detector 111. In relation to the output, the smaller the peak waveform width a, the better. This peak waveform greatly depends on the numerical aperture of the objective lens 107, and it is known that the resolution is lowered particularly with a low-magnification objective lens having a small numerical aperture.

  On the other hand, conventionally, for example, as disclosed in Patent Document 1, a Mirau two-beam interference objective lens is used, and the distance between the surface of the sample and the focal point of the objective lens is obtained every time a quarter wavelength shifts. The resolution is improved by detecting the maximum peak when the focal point of the sample coincides with the focus of the sample signal, and a high-resolution measurement is possible even with a low-magnification objective lens with a small numerical aperture. Yes.

On the other hand, as what performs micro three-dimensional measurement, as disclosed in Patent Document 2, a confocal signal obtained from reflected light input to a detector from a sample of a laminated structure through a condenser lens and a pinhole, and There has been proposed an apparatus capable of measuring a layer thickness of a laminated structure based on an interference signal obtained from reference light input to a detector through a condenser lens and a pinhole through a reference mirror.
Japanese Patent No. 3037825 Japanese Patent No. 3459327

  However, although the thing of the patent document 1 implement | achieved the improvement of the resolution of the height direction with respect to a sample, since the two-beam interference objective lens is used, it is always from an interference pattern and a reference mirror on the observation image of a sample. The reflected light rides as a background and a high-quality image cannot be obtained. That is, such a thing of patent document 1 impairs the big characteristic of a laser confocal microscope that a high-resolution confocal image with good contrast can be obtained. Further, the one in Patent Document 2 has a configuration in which a confocal signal obtained from a confocal optical system having a condenser lens and a pinhole and an interference signal obtained from reference light are combined without using a two-beam interference objective lens. Although shown, only measurement at a certain point on the sample is assumed, and measurement of height information at each point on the sample surface based on two-dimensional scanning is not considered.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a laser scanning confocal microscope capable of improving the resolution of height measurement and obtaining a confocal image with good contrast. And

  According to a first aspect of the present invention, there is provided a light source that generates laser light, an objective lens that condenses the laser light generated from the light source on a sample, and a laser beam that is disposed at a position conjugate with a pupil position of the objective lens. Is arranged on the optical path divided by the optical path dividing means for dividing the optical path of the laser beam, the optical path dividing means for dividing the optical path of the laser beam. A reflection optical system unit having a reflection optical system for reflecting laser light scanned by the scanning means, and the reflection optical system unit or the reflection optical system can be inserted into and removed from the optical path between the objective lens and the scanning means. Interference caused by interference between the reflected light from the sample surface or the reflected light from the reflective optical system and the reflected light from the sample. A very small aperture for passing a turn, is characterized by comprising a light-detecting means for detecting the intensity of light passing through the microscopic aperture.

  According to a second aspect of the present invention, in the first aspect of the invention, the reflective optical system includes a condenser lens in which a pupil position is arranged at a position conjugate with the pupil position of the objective lens, and the condenser lens. It has a reflection means arranged at the focal position.

  A third aspect of the invention is characterized in that, in the first aspect of the invention, the reflective optical system has a corner cube in which a vertex position is arranged at a position conjugate with a pupil position of the objective lens.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the insertion / removal unit includes an optical path blocking unit that can block the optical path divided by the optical path dividing unit. It is said.

  According to a fifth aspect of the present invention, in the invention according to the second or third aspect, the reflecting optical system unit is configured such that the relative position relationship between the condenser lens and the reflecting unit with respect to the optical path dividing unit or the relative of the corner cube with respect to the optical path dividing unit The optical system is characterized in that the optical path between the objective lens and the scanning unit is inserted and removed by the insertion / removal unit in a state where the positional relationship is kept constant.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, further comprising: a light source that emits illumination light having an arbitrary wavelength; and the illumination light emitted from the light source is emitted from the objective lens. A light introduction means for introducing on the axis, and an image acquisition means for obtaining a non-confocal image of the sample by detecting reflected light from the sample irradiated with the illumination light introduced by the light introduction means, The light introducing means and the optical path dividing means are formed integrally.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the resolution of height measurement, the laser scanning confocal microscope which can obtain a confocal image with favorable contrast can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a schematic configuration of a laser scanning confocal microscope according to a first embodiment of the present invention.

  In the figure, 1 is a light source, and the light source 1 is a point light source such as a laser beam. A polarizing beam splitter (hereinafter referred to as PBS) 2 is disposed on the optical path of light from the light source 1. The PBS 2 transmits light (laser light) from the light source 1 and reflects reflected light from the sample 8 and the reference mirror 23 described later.

  On the optical path of the light of the light source 1 that passes through the PBS 2, an XY light deflection unit 3 as a scanning means is arranged. This XY light deflection unit 3 has two galvanometers (not shown) for deflecting light in two orthogonal directions, and these galvanometers two-dimensionally transmit light on the surface of the sample 8 and the reference mirror 23 described later. It is designed to scan. The XY light deflection unit 3 is disposed at a position conjugate with a pupil of an objective lens 7 to be described later.

  On the optical path of the light emitted from the XY light deflection unit 3, a pupil projection lens 5, a λ / 4 plate 4, and a first beam splitter (hereinafter referred to as a first BS) 19 are arranged. The λ / 4 plate 4 converts the light emitted from the XY light deflection unit 3 from linearly polarized light to circularly polarized light. The first BS 19 reflects light (laser light) from the light source 1 and transmits light (white light) from an illumination optical system 17 described later.

  On the optical path of the light of the light source 1 that reflects the first BS 19, an imaging lens 6, a second beam splitter (hereinafter referred to as a second BS) 16 as an optical path dividing means, and an objective lens 7 are arranged. Has been. The imaging lens 6 makes light that has passed through the pupil projection lens 5 (light that has been two-dimensionally scanned by the XY light deflection unit 3) incident on the pupil of the objective lens 7. The second BS 16 transmits the light (laser light) from the light source 1, partially divides and reflects the optical path of the laser light, and reflects light (white light) from the illumination optical system 17 described later. To do. The objective lens 7 converges the incident light, and the converged spot light is two-dimensionally scanned in the plane direction (X, Y direction) perpendicular to the optical axis on the surface of the sample 8 by the operation of the XY light deflection unit 3. Let The objective lens 7 is held by a revolver unit 14 that can move in the optical axis direction, and is moved in the optical axis direction (Z direction) by the movement of the revolver unit 14 so that the relative position with respect to the sample 8 is continuously changed. It is variable. The revolver unit 14 is provided with a Z scale 141. The Z scale 141 can measure the amount of movement of the revolver unit 14, that is, the amount of movement of the objective lens 7 in the optical axis direction. In this case, the movement of the revolver unit 14 is controlled by the controller 12, and the measured value of the Z scale 141 is taken into the controller 12.

  The reflected light from the sample 8 is guided to the λ / 4 plate 4 through the second BS 16, the imaging lens 6, and the first BS 19, converted from circularly polarized light to linearly polarized light, and then the pupil projection lens 5. Return to the PBS 2 via the XY light deflection unit 3.

  On the reflected light path of the reflected light returned to the PBS 2, a condenser lens 9 and a detector 11 as a light detecting means are arranged through a pinhole 10 as a minute aperture. The condensing lens 9 irradiates the pinhole 10 with the reflected light returned to the PBS 2 in a spot shape. The pinhole 10 is disposed at a position optically conjugate with the condensing position of the objective lens 7 and allows the focused component of the light reflected from the sample 8 to pass through, but prevents the unfocused component from transmitting. It has become. The detector 11 comprises a photomultiplier or the like, detects light that has passed through the pinhole 10, converts the luminance of this light into an electrical signal, and outputs it. In this case, the light detected by the detector 11 has the maximum luminance when it is focused on the sample 8, and conversely, the luminance is extremely small when it is out of focus with respect to the sample 8.

  A controller 12 is connected to the detector 11. The controller 12 is connected to a monitor 15. An electrical signal corresponding to the luminance of the light detected by the detector 11 is input to the controller 12, and this signal is displayed on the monitor 15 as an image.

  On the other hand, reference numeral 17 denotes an illumination optical system. A white illumination fiber 18 is connected to the illumination optical system 17, and white illumination light is introduced through the white illumination fiber 18. In this case, for example, halogen or mercury is used as the light source of the white illumination light. The second BS 16 is arranged on the optical path of white illumination light having an arbitrary wavelength from the illumination optical system 17. The second BS 16 also constitutes light introducing means for introducing the illumination light from the illumination optical system 17 onto the optical axis of the objective lens 7, reflects the introduced illumination light, and is applied to the sample 8 by the objective lens 7. Irradiate.

  The reflected light from the sample 8 passes through the second BS 16 and further passes through the imaging lens 6 and the first BS 19. A CCD camera 21 is disposed on the optical path of the reflected light that passes through the first BS 19 via a camera lens 20 as image acquisition means. The CCD camera 21 captures an observation image of the sample 8 formed by the camera lens 20. A controller 12 is connected to the CCD camera 21. The controller 12 displays an observation image captured by the CCD camera 21 on the monitor 15.

  On the divided optical path divided by the second BS 16, a shutter 24 as an optical path blocking unit, a condensing lens 22, and a reference mirror 23 as a reflecting unit are arranged. In this case, the second BS 16, the condenser lens 22, and the reference mirror 23 constitute a reflection optical system unit 25. The shutter 24 switches between a normal laser scanning confocal microscope function and a function combining the laser scanning confocal microscope with interference pattern detection. An optical path divided by the second BS 16 and incident on the condenser lens 22. Can be shut off. The pupil position of the condenser lens 22 is disposed at a position conjugate with the pupil position of the objective lens 7 and the XY light deflection unit 3. Further, the reference mirror 23 is arranged at a position conjugate with the focal position of the condenser lens 22, that is, the focal position of the objective lens 7. In this case, when the light (laser light) from the light source 1 partially divided by the second BS 16 is incident on the pupil of the condenser lens 22 and irradiated on the reference mirror 23, the pupil position of the condenser lens 22 And the XY light deflection unit 3 are in a conjugate positional relationship, the reflected light from the reference mirror 23 reflects the second BS 16 and follows the same optical path as the reflected light of the sample 8 and is detected by the detector 11. Is done.

  Next, the operation of the embodiment configured as described above will be described.

  First, when used as a normal laser scanning confocal microscope, the shutter 24 is closed to block the optical path incident on the condenser lens 22.

  In this state, light (laser light) from the light source 1 passes through the PBS 2 and enters the XY light deflection unit 3. Then, the laser light scanned two-dimensionally by the XY light deflection unit 3 is incident on the first BS 19 via the pupil projection lens 5 and the λ / 4 plate 4, and is reflected there to form the imaging lens 6. The light enters the pupil of the objective lens 7 through the second BS 16. And it collects on the sample 8 with the objective lens 7, and becomes spot light. Further, spot light is two-dimensionally scanned on the surface of the sample 8 by two-dimensional scanning by the XY light deflection unit 3.

  Reflected light from the sample 8 is incident on the sample 8 described above via the second BS 16, the imaging lens 6, the first BS 19, the λ / 4 plate 4, the pupil projection lens 5, and the XY light deflection unit 3. Return to PBS2 through the exact same path as when you did. In this case, the light emitted from the XY light deflection unit 3 is converted from linearly polarized light to circularly polarized light by the λ / 4 plate 4, and the reflected light from the sample 8 passes through the λ / 4 plate 4 to be linearly converted from the circularly polarized light. Converted to polarized light. That is, the relationship between the light from the light source 1 and the reflected light from the sample 8 is linearly polarized light rotated by 90 °. As a result, the reflected light from the sample 8 is reflected by the PBS 2, is spotted by the condenser lens 9, and enters the pinhole 10. Since the reflected light from the sample 8 at this time returns after passing through the XY light deflection unit 3, the incident position on the pinhole 10 does not move even when scanning off-axis.

  In this state, since the pinhole 10 is in a conjugate position with the focal position of the objective lens 7, the reflected light from the surface of the sample 8 focused on the surface of the sample 8 passes through the pinhole 10 and is out of focus. Reflected light from the surface of a certain sample 8 does not pass through the pinhole 10. As a result, only the light that has passed through the pinhole 10 is detected by the detector 11, and a signal corresponding to the intensity of the detected light is output to the controller 12. The controller 12 obtains a confocal image of the sample 8 by performing image processing on the output signal of the detector 11 at a timing when the laser beam is scanned on the sample 8 by the XY light deflection unit 3, and displays this on the monitor 15. At the same time, it is stored in an image memory (not shown).

  Thereafter, the revolver unit 14 moves the objective lens 7 by a predetermined distance in the optical axis direction to execute the above-described operation, and acquires a confocal image of the sample 8 according to the position of the objective lens 7 at this time. Similarly, the above-described confocal image acquisition is repeatedly performed while moving the objective lens 7 by a predetermined distance in the optical axis direction within a predetermined range.

  Then, from the plurality of confocal images stored in the image memory (not shown) by the above-described repetitive operation, the luminance and the height information at that time are extracted from each pixel, and a three-dimensional image including the height information is extracted. Is displayed on the monitor 15.

  Next, when used as a normal optical microscope, the shutter 24 is also closed at this time to block the optical path incident on the condenser lens 22.

  In this state, the white illumination light introduced from the white illumination fiber 18 is reflected by the second BS 16 via the illumination optical system 17 and irradiated onto the sample 8 via the objective lens 7. Further, the white light reflected from the sample 8 passes through the objective lens 7, the second BS 16, the imaging lens 6, and the first BS 19, and is imaged on the imaging surface of the CCD camera 21 by the camera lens 20, and the microscope Captured as an image. The microscope image picked up by the CCD camera 21 is sent to the controller 12. The controller 12 displays the microscope image on the monitor 15. Thereby, a general microscope image can be acquired.

  Next, when combining interference pattern detection with a laser scanning confocal microscope, the shutter 24 is opened and the optical path incident on the condenser lens 22 is opened.

  In this state, when laser light is emitted from the light source 1, it is scanned two-dimensionally by the XY light deflection unit 3 in the same manner as described above, passes through the second BS 16, and is collected on the sample 8 by the objective lens 7. The sample 8 is two-dimensionally scanned on the surface of the sample 8 by two-dimensional scanning by the XY light deflection unit 3, and the reflected light from the sample 8 reverses exactly the same path as that incident on the sample 8 described above. And is guided to the detector 11 side.

  On the other hand, a part of the laser light from the light source 1 is reflected by the second BS 16, enters the pupil of the condenser lens 22, and is applied to the reference mirror 23. In this case, the pupil position of the condenser lens 22 is arranged at a position conjugate with the pupil position of the objective lens 7 and the XY light deflection unit 3, and the reference mirror 23 is the focal position of the condenser lens 22, that is, the objective lens 7. Therefore, the reflected light of the light scanned on the reference mirror 23 is detected by reflecting the second BS 16 and following the same optical path as the reflected light of the sample 8. To the container 11 side.

  At this time, in the second BS 16, the reflected light from the reference mirror 23 and the reflected light from the above-described sample 8 are merged, and the merged light causes interference. The light in this state becomes an interference pattern and passes through the pinhole 10 and is detected by the detector 11.

  As described above, when the image acquisition is repeated while the objective lens 7 is moved by a predetermined distance in the optical axis direction by the revolver unit 14 as described above, the relationship between the relative distance between the objective lens 7 and the sample 8 and the detected light intensity is as follows. 2 (a) and 2 (b). That is, FIG. 2A shows an interference pattern before 10 pinholes, and here, the interference intensity is substantially constant. However, since the reflected light from other than the focal position of the objective lens 7 is blocked by passing through the pinhole 10, the interference intensity (detection) is detected in the vicinity of the focal position of the objective lens 7 as shown in FIG. An interference pattern with a maximum (light intensity) is obtained. In this interference pattern, the characteristic portion indicated by the dotted line b in FIG. 2B depends on the characteristic of the confocal optical system, that is, the numerical aperture of the objective lens 7. Accordingly, in FIG. 2B, the peak position c at which the interference intensity of the interference pattern is maximized is obtained, so that the resolution is higher than that when using only the confocal optical system described in FIG. A high-resolution height measurement can be performed even with a low-magnification objective lens having a small numerical aperture.

  Also in this case, the revolver unit 14 moves the objective lens 7 by a predetermined distance in the optical axis direction to execute the above-described operation, and obtains an interference pattern corresponding to the position of the objective lens 7 at this time. Similarly, the above-described interference pattern acquisition is repeatedly performed while moving the objective lens 7 by a predetermined distance in the optical axis direction within a predetermined range. Then, from the plurality of interference patterns acquired by the above-described repetitive operation, the luminance with the highest luminance and the height information at that time are extracted from each pixel, and a three-dimensional image including the height information is constructed and monitored. 15 is displayed.

  Therefore, in this way, the shutter 24, the pupil position of the objective lens 7, and the XY light deflection unit 3 are conjugate with the reflected light path of the second BS 16 that divides the optical path of the light (laser light) from the light source 1. The condensing lens 22 whose pupil position is arranged at the position and the reference mirror 23 arranged at the focal position of the condensing lens 22 are arranged, and the light scanned on the reference mirror 23 is opened with the shutter 24 opened. The reflected light follows the same optical path as the reflected light of the sample 8 and is introduced to the detector 11 side. At this time, the reflected lights interfere with each other, and the interference pattern is detected by the detector 11 through the pinhole 10. In this case, the interference pattern has a maximum amplitude at the focal position of the objective lens 7 because the reflected light from the focal position of the objective lens 7 is blocked by the pinhole 10 and the peak waveform of the interference pattern obtained at this time. Has a smaller half-value width than the peak waveform in the confocal optical system, and can obtain results with higher resolution than the optical resolution when using only the confocal optical system. Even when a low-magnification objective lens with a small numerical aperture is used, high-resolution height measurement can be performed.

  Further, the optical path can be selectively blocked by the shutter 24, and only the optical path through the objective lens 7 can be used by blocking the optical path to the condenser lens 22 side. The interference pattern and the reflected light from the reference mirror 23 do not ride as the background, and a confocal image with good contrast can be obtained while maintaining the characteristics of the laser scanning confocal microscope.

  Furthermore, since the light on the surface of the sample 8 is two-dimensionally scanned by the XY light deflection unit 3 and the light on the surface of the reference mirror 23 is also two-dimensionally scanned, at each point on the sample surface by these two-dimensional scanning. Measurement of height information can be realized.

  In the first embodiment described above, the second BS 16 serves as a white illumination introduction unit into which light (white light) from the illumination optical system 17 is introduced. Alternatively, it may be provided separately from the second BS 16. In this case, of course, it is advantageous in terms of space that the second BS 16 also serves as the white illumination introducing portion. In the first embodiment, the shutter 24 for blocking the reflected light path of the second BS 16 is arranged. However, as a means for blocking the light path, the second BS 16 is switched to another characteristic. This is also possible.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  FIG. 3 shows a schematic configuration of the second embodiment of the present invention. The same parts as those in FIG.

  In this case, instead of the condensing lens 22 and the reference mirror 23 of the first embodiment, a corner cube unit 31 as a reflection optical system unit is used. As shown in FIG. 4, the corner cube unit 31 has a third beam splitter (hereinafter referred to as a third BS) 32 disposed at one end inside the lens barrel 311 and a corner cube 33 disposed at the other end. Is arranged. Further, the corner cube unit 31 can be inserted into and removed from the revolver unit 14 by an unillustrated insertion / removal means, and the third BS 32 can be inserted into the optical path between the second BS 16 and the objective lens 7. The third BS 32 transmits the light (laser light) from the light source 1 while being inserted in the optical path, and divides and reflects a part of the light, and the reflected light is transmitted to the corner cube 33. Incident. The corner cube 33 is a combination of plane plates that reflect light at an angle of 90 °, and the light incident from the third BS 32 is reflected once by each plane plate to the original third BS 32. It is made to enter. In this case, the vertex position d formed by each plane plate of the corner cube 33 is arranged at a position conjugate with the pupil position of the objective lens 7.

  In such a configuration, when combining an interference pattern detection function with a laser scanning confocal microscope, the corner cube unit 31 is inserted into the optical path.

  In this state, when laser light is emitted from the light source 1, it is scanned two-dimensionally by the XY light deflection unit 3 in the same manner as described above, passes through the second BS 16, and is collected on the sample 8 by the objective lens 7. The sample 8 is two-dimensionally scanned on the surface of the sample 8 by two-dimensional scanning by the XY light deflection unit 3, and the reflected light from the sample 8 reverses exactly the same path as that incident on the sample 8 described above. And is guided to the detector 11 side.

  On the other hand, a part of the laser light from the light source 1 is reflected by the third BS 32 and enters the corner cube 33. In this case, since the vertex position d of the corner cube 33 is arranged at a position conjugate with the pupil position of the objective lens 7, the reflected light incident on the third BS 32 from the corner cube 33 passes through the third BS 32. The light is reflected and follows the same optical path as the reflected light of the sample 8 and is guided to the detector 11 side.

  At this time, the reflected light from the corner cube 33 and the reflected light from the sample 8 are merged in the third BS 32, and the merged light causes interference. And the light of this state is guide | induced to the detector 11, and the image of an interference pattern is detected.

  Therefore, even if it does in this way, the effect similar to 1st Embodiment can be acquired. In addition, by setting the apex of the corner cube 33 to a position conjugate with the pupil of the objective lens 7, it is possible to obtain an operation equivalent to the combination of the condenser lens 22 and the reference mirror 23 of the first embodiment. Since the position conjugate with the pupil position of the objective lens 7 can be adjusted only by adjusting the position of the corner cube 33, the work for the position adjustment can be simplified. Further, the corner cube unit 31 is configured by combining the corner cube 33 and the third BS 32, and the corner cube unit 31 is detachably attached to the revolver unit 14, and functions of the shutter 24 according to the first embodiment. Therefore, the configuration can be simplified and the price can be reduced. Further, since the revolver unit 14 to which the corner cube unit 31 is attached moves integrally with the objective lens 7 in the optical axis direction (Z direction), the relative positional relationship between the objective lens 7 and the corner cube unit 31 is such that the revolver unit 14 Since it does not change even if it moves in the axial direction, it becomes possible to perform more accurate height measurement. Further, if a plurality of objective lenses 7 with different magnifications are attached to the revolver unit 14, interference pattern images with different magnifications can be detected without preparing a plurality of objective lenses for interference.

  Instead of the corner cube unit 31, the second BS 16, the condenser lens 22, and the reference mirror 23 described in the first embodiment may be unitized so as to be detachable from the revolver unit 14.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not change the summary.

  Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. If the above effect is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.

The figure which shows schematic structure of the laser scanning confocal microscope concerning the 1st Embodiment of this invention. The figure explaining the interference intensity | strength of the interference pattern acquired by 1st Embodiment. The figure which shows schematic structure of the laser scanning confocal microscope concerning the 2nd Embodiment of this invention. The figure which shows schematic structure of the corner cube unit used for 2nd Embodiment. The figure which shows schematic structure of the conventional laser scanning confocal microscope. The figure which shows the relationship between the relative distance of an objective lens and a sample, a movement distance, and the output of a detector.

Explanation of symbols

1 ... light source, 2 ... PBS
DESCRIPTION OF SYMBOLS 3 ... XY light deflection unit, 4 ... (lambda) / 4 board 5 ... Pupil projection lens, 6 ... Imaging lens 7 ... Objective lens, 8 ... Sample 9 ... Condensing lens, 10 ... Pinhole 11 ... Detector, 12 ... Controller 14 ... Revolver part 141 ... Z scale 15 ... Monitor 16 ... Second BS
DESCRIPTION OF SYMBOLS 17 ... Illumination optical system, 18 ... White illumination fiber 19 ... 1st BS, 20 ... Camera lens 21 ... CCD camera, 22 ... Condensing lens 23 ... Reference mirror, 24 ... Shutter, 25 ... Reflective optical system unit 31 ... Corner cube unit, 311 ... barrel 32 ... third BS, 33 ... corner cube

Claims (6)

A light source that generates laser light;
An objective lens for condensing the laser beam generated from the light source on the sample;
Scanning means arranged at a position conjugate with the pupil position of the objective lens and scanning the laser beam on the sample surface;
An optical path dividing unit arranged in an optical path between the objective lens and a scanning unit and dividing an optical path of the laser beam, and a laser beam arranged in an optical path divided by the optical path dividing unit and reflected by the scanning unit are reflected. A reflective optical unit having a reflective optical system;
Insertion / removal means capable of inserting / removing the reflection optical system unit or the reflection optical system with respect to the optical path between the objective lens and the scanning means;
A minute aperture that is disposed at a position conjugate with the focusing position of the objective lens, and that allows the reflected light from the sample surface or the reflected light from the reflective optical system to pass through an interference pattern due to interference of the reflected light from the sample;
A laser scanning confocal microscope, comprising: a light detection unit that detects an intensity of light passing through the minute aperture. The reflection optical system includes a condensing lens in which a pupil position is arranged at a position conjugate with a pupil position of the objective lens, and reflecting means arranged in a focal position of the condensing lens. Item 2. A laser scanning confocal microscope according to Item 1. 2. The laser scanning confocal microscope according to claim 1, wherein the reflection optical system includes a corner cube in which a vertex position is arranged at a position conjugate with a pupil position of the objective lens. The laser scanning confocal microscope according to any one of claims 1 to 3, wherein the insertion / removal unit includes an optical path blocking unit configured to block an optical path divided by the optical path dividing unit. The reflective optical system unit is configured so that the relative positional relationship between the condenser lens and the reflecting unit with respect to the optical path dividing unit or the relative positional relationship of the corner cube with respect to the optical path dividing unit is held constant by the insertion / removal unit. 4. The laser scanning confocal microscope according to claim 2, wherein the laser scanning confocal microscope is inserted into and removed from an optical path between the objective lens and the scanning means. Further, a light source that emits illumination light having an arbitrary wavelength, light introduction means that introduces illumination light emitted from the light source onto the optical axis of the objective lens, and illumination light introduced by the light introduction means are irradiated. Image acquisition means for detecting reflected light from the sample and acquiring a non-confocal image of the sample,
6. The laser scanning confocal microscope according to claim 1, wherein the light introducing unit and the optical path dividing unit are integrally configured.

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