JPH11305133A - High resolution microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily realize super resolution without requiring a complicated mechanism. SOLUTION: The high resolution microscope includes a light source 1, a collector lens 2, a polarized light separating optical system 51, a polarizer 3, a condenser lens 5, a sample 6, an objective lens 7, a polarized light synthesizing optical system 52, and an image forming lens 10 arranged in the order of light passage, the optical system 51 separates an incident beam into two illuminiating beams of which polarizing directions intersect with each other at right angles, the optical system 52 synthesizes diffracted beams diffracted from the sample 6 and having different polarization directions, and both the optical systems 51, 52 respectively include polarized beam splitters and mirrors. Each mirror is constituted so that incident light upon each of the optical systems 51, 52 passes the polarized beam splitter twice, two separated illuminating beams are allowed to pass respectively different positions on the pupil surface of an illuminating optical system and a pair of light rays separated from the same light ray out of these illuminating beams are applied to the same point on a sample surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-resolution microscope, and more particularly to a high-resolution microscope that can realize super-resolution relatively easily.

[0002]

2. Description of the Related Art Observation with higher spatial resolution is required in fields such as observation and measurement of a minute structure of a sample and defect inspection. As a method for increasing the in-plane resolution of the sample, in order to form an image of a high spatial frequency component in the diffracted light from the sample, the sample is located near the sample surface or at a position conjugate with the sample surface in the illumination optical system. There is a method of applying a certain type of modulation to the diffracted light or the illumination light, respectively, and performing demodulation corresponding to the modulation at a position substantially conjugate with the sample surface in the imaging optical system. An example of this is the method of Lukosz (W. Lukos
z, "Optical systems with resolving powers exceeding
the clasical limit.II ", Journal of the Optical Soc
society of America, Vol. 37, PP. 932 (1967)) and Lohma
nn et al. (AWLohmann and DPParis, "Superres
olution for Nonbirefringent Objects ", Applied Optic
s, Vol.3, PP.1037 (1964)).

FIG. 12 shows an optical system of the Lukosz method. In Lukosz's method, diffraction gratings 101 and 102 having conjugate lattice constants are arranged near the sample 6 and at a position substantially conjugate with the sample surface in the imaging optical system, and move them conjugately. The diffraction grating 101 arranged in the vicinity of the sample surface can make diffracted light that cannot originally enter the objective lens 7 of the imaging optical system reach the image plane 11. Diffraction grating 102 arranged at a position substantially conjugate with the sample surface in the imaging optical system
As a result, the light diffracted by the diffraction grating 101 near the sample surface is demodulated and formed as an original diffraction component. Light having a high spatial frequency component that originally did not contribute to image formation reaches the image plane 11 by the diffraction grating 101, so that a higher spatial resolution than usual can be obtained.

FIG. 13 shows an optical system according to the method of Lohmann et al. According to the method of Lohmann et al., Birefringent prisms 4 and 8 such as Wollaston prisms are arranged at positions substantially conjugate with the sample surface on the front side of the condenser lens 5 and on the rear side of the objective lens 7, respectively. The incident light that has passed through the polarizing plate 3 is separated into two polarized lights whose vibration directions are orthogonal to each other by a birefringent prism 4 on the front side of the condenser lens. Pass through. The irradiation positions of the separated two polarized lights coincide with each other on the sample surface. The two orthogonally polarized lights separated from the same light beam are obliquely incident on the sample 6 at different angles, and the diffracted lights for each pass through the objective lens 7 independently. The two polarized lights interfere with each other by the birefringent prism 8 disposed behind the objective lens 7 to form an image.
Diffracted light having a high spatial frequency component corresponding to the oblique incident angle of the two orthogonally polarized lights to the sample 6 passes through the objective lens 7 as independent two polarized lights, and interferes on the image plane 11. , A higher spatial resolution can be realized.

[0005]

In the method of Lukosz, two diffraction gratings on the sample side and the image plane need to be continuously moved in synchronization with each other, and the mechanism becomes very complicated.
On the other hand, the method of Lohmann et al. Has the advantage that there is no complicated movable part unlike the method of Lukosz. However, since the share amount of the Wollaston prism and the like is fixed, it is necessary to obtain optimal resolution and contrast. In addition, it is impossible to adjust the separation position of the orthogonal two polarized lights on the pupil plane of the condenser lens. In addition, super-resolution is obtained in the direction of polarization separation by a Wollaston prism or the like, but in order to obtain super-resolution in other directions, a polarizer or a Wollaston prism is rotated with respect to the optical axis. Or the sample needs to be rotated with respect to the optical axis, and the operation becomes complicated. This is shown in FIGS. 14 (a), (b),
This will be described with reference to (c). 14 (a), (b), (c)
Shows the luminous flux of the zero-order light in the scattered light (diffracted light) from the sample 6 passing through the pupil plane of the objective lens 7 in FIG. Reference numeral 7a indicates a pupil region in a certain objective lens, and reference numerals 41d and 42d indicate light beams of the 0th-order diffracted light corresponding to the two light beams separated by polarization. The center positions of the light beams 41d and 42d are represented by points 41c and 42c. Considering the case where an objective lens having a smaller pupil is used instead of this objective lens, the angle α of the polarization separation by the Wollaston prism 4 shown in FIG. 13 does not change, and as shown in FIG. While the positions of the points 41c and 42c in the pupil plane of the objective lens remain unchanged, the pupil 7a 'of the objective lens and the light beams 41d',
Only the size of 2d 'is reduced. Therefore, the two light beams 41d ', 42 relative to the pupil 7a' of the objective lens
The position of d 'largely deviates from the pupil 7a'. Since the relative positions of the light beams 41c and 42c with respect to the pupil 7a affect the resolving power and contrast, they cannot be adjusted unless α is changed. The super-resolution is obtained with respect to the direction of separation of the polarized light beam (x-axis direction in FIG. 13). If it is desired to obtain the super-resolution in a direction perpendicular to this direction, FIG. It is necessary that the light beams 41d and 42d of the 0th-order diffracted light be separated in the y-axis direction as described above. However, for this purpose, it is necessary to rotate the Wollaston prisms 4 and 8 on the illumination side and the imaging side together with the polarizer 3. Alternatively, the sample 6 needs to be rotated.

On the other hand, in order to increase the amount of separation of the illumination light beam, for example, in the case where the illumination light beam is polarization-separated in order to obtain super-resolution for an objective lens having a large pupil, the polarization separation shown in FIG. It is necessary to increase the separation angle α of the birefringent prisms. As the birefringent prisms 4 and 8 become thicker, the deviation between the exit direction of the light beam entering the prism at an angle and the exit direction of the light beam perpendicularly incident on the prism increases. In addition, a difference appears in the intensity between a pair of polarized light beams. Therefore, it causes deterioration of image contrast.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a high-resolution microscope capable of relatively easily realizing super-resolution without requiring a complicated mechanism. To provide. It is another object of the present invention to provide a high-resolution microscope which has a mechanism capable of adjusting the resolution and the direction in which the super-resolution is obtained, and in which the contrast is hardly deteriorated.

[0008]

To achieve the above object, a high-resolution microscope according to the present invention comprises a collector lens for guiding light from a light source to an illumination optical system, an illumination optical system for illuminating a sample, and a In a microscope configured with an objective lens that captures diffracted light, a polarization separation optical system that separates an incident light beam into two illumination light beams whose polarization directions are orthogonal to each other is arranged between a collector lens and an illumination optical system. Between the image detection positions, a polarization combining optical system that combines diffracted lights having different polarization directions diffracted from the sample by the illumination light beam is arranged, the polarization separation optical system includes a polarizing beam splitter and a mirror, and the mirror is The light incident on the polarization splitting optical system is configured to pass through the polarizing beam splitter twice, and the two illumination light beams are different on the pupil plane of the illumination optical system. And a pair of light beams separated from the same light beam in each of the illumination light beams illuminate the same point on the sample surface, and the polarization combining optical system includes a polarizing beam splitter and a mirror. Wherein the mirror is configured such that light incident on the polarization combining optical system passes twice through the polarization beam splitter.

FIG. 1 shows the configuration of a transmission microscope according to the present invention, and the above means and operation of the present invention will be described. The illumination optical system of the microscope of FIG. 1 includes a light source 1, a collector lens 2, a polarizer 3, a polarization separation optical system 51, and a condenser lens 5, while the imaging optical system includes an objective lens 7, a polarization combining optical system 52, It comprises an imaging lens 10. In FIG. 1, the illumination light beam traveling on the optical axis from the light source 1 and the zero-order light beam that is not diffracted by the sample 6 are represented by straight lines.
The light emitted from the light source 1 passes through the collector lens 2, becomes linearly polarized light by the polarizer 3, and enters the polarization separation optical system 51 in the illumination optical system. The polarizer 3 is arranged so that its polarization direction forms an angle of 45 ° with the two polarized lights separated by the polarization separation optical system 51. The polarization splitting optical system 51 splits the incident light into two light beams 41 and 42 (FIG. 2) whose polarization directions are orthogonal to each other. Luminous flux 41, 4
2 enters the condenser lens 5 and illuminates the sample 6. On the other hand, the scattered light (diffracted light) by the sample 6 passes through the objective lens 7 and enters the polarization combining optical system 52 in the imaging optical system. The zero-order lights 41d and 42d that are not diffracted by the sample 6 corresponding to the illumination light beams 41 and 42 are combined by the polarization combining optical system 52, and formed into an image at the image detection position 11 by the imaging lens 10.

The polarization splitting optical system 51 of the present invention has the polarization beam splitter 21 and mirrors 22 and 23, and the polarization combining optical system 52 has the polarization beam splitter 6
1 and mirrors 62 and 63. The polarizing beam splitter 21 and the polarizing beam splitter 61 are arranged at positions substantially conjugate with the sample surface. Polarization separation optical system 51
Is split by the polarization beam splitter 21, is reflected by the mirrors 22 and 23, reenters the polarization beam splitter 21, and is emitted from the polarization splitting optical system 51.

FIG. 2 shows the relative positional relationship between the pupil 7a of the objective lens 7 and the passage areas of the illumination light beams 41 and 42 in the pupil plane of the condenser lens 5. FIG.
As shown in (b), the illumination light beams 41 and 42 separated by the polarization separation optical system 51 pass through different positions on the pupil plane of the condenser lens 5. A pair of light beams separated from the same light beam in the illumination light beams 41 and 42 irradiate the same point on the sample surface. Light scattered from this point is combined by the polarization combining optical system 52. In FIG. 1, of the light separated by the polarization splitting optical system 51 and combined by the polarization combining optical system 52, the light paths through which the light beams 41 and 41d pass, and the light beams 42 and 4
The optical path length difference from the optical path through which 2d passes is substantially zero.

On the pupil plane of the objective lens 7, assuming that the zero-order light beams 41d and 42d corresponding to the illumination light beams 41 and 42 of FIG. 2B are 41d and 42d, the region through which the diffracted light by the light beam 41 can pass is shown in FIG. 4B), the region through which the diffracted light by the light beam 42 can similarly pass is indicated by the hatched portion 42f in FIG.
Indicated by Since the light beams 41 and 42 have polarization directions orthogonal to each other, and the diffracted light beams do not interfere on the pupil plane, the regions 41f and 42f are the same as the region of the pupil 7a of the objective lens 7; Is considered to be a region where independent diffracted light exists on the pupil plane. Diffracted light from the sample 6 by the light beams 41 and 42 is combined by the polarization combining optical system 52. Light flux 41d, 42d
Are light emitted from the same region on the sample surface, so that the light beams 41d and 42d become identical light beams after passing through the polarization combining optical system 52. Therefore, the apparent area through which the diffracted light from the sample 6 can pass on the pupil plane of the objective lens 7 is the luminous fluxes 41d and 42 in FIGS. 4 (a) and 4 (b).
An area is obtained by combining the hatched portions 41f and 42f when d is matched. This is shown in FIG.

Accordingly, the area through which the diffracted light can pass is only the inside 71f of the pupil 7a as shown in FIG.
As shown in FIG. 3B, in the region 72f where the apparent regions 41f and 42f are combined, the pupil 7a can be expanded to about twice as large as the pupil 7a. The larger the size of the pupil, the higher the resolution because the diffracted light due to the high spatial frequency component of the sample can pass through the imaging optical system. Therefore, according to the microscope of the present invention,
Observation far beyond the resolution of a normal microscope can be performed.

Further, A.I. W. Although the transmission type optical system shown by Lohmann et al. Uses a birefringent prism such as a Wollaston prism, the configuration of the present invention does not use a birefringent prism, so that the angle of polarization separation by the birefringent prism is increased. No degradation in contrast caused by the prism thickness occurs.

FIG. 1 shows the configuration of a transmission microscope. The high-resolution microscope of the present invention is an epi-illumination microscope using an objective lens also as an illumination optical system, and includes a collector lens and a polarization separation optical system. A beam splitter for separating an illumination light beam and an image forming light beam may be arranged between the systems or between the polarization splitting optical system and the objective lens.

The beam splitter is disposed between the collector lens and the polarization splitting optical system, and the polarization splitting optical system and the polarization combining optical system are configured as a common polarization splitting / synthesizing optical system. -The polarization conversion element may be arranged between the combining optical system and the objective lens. With this configuration, a high-resolution microscope can be realized with fewer optical elements. As the polarization conversion element, a quarter-wave plate or an optical element having a function equivalent to that of the quarter-wave plate can be used.

The polarization splitting optical system can be configured such that the position of the two illumination light beams passing on the pupil plane of the illumination optical system changes when the mirror is tilted. In addition, the position at which the two illumination light beams pass on the pupil plane of the illumination optical system can be changed by moving the mirror. At this time, the mirror in the polarization combining optical system is also tilted or moved so that the zero-order light for the illumination light beam is combined by the polarization combining optical system. In the optical system of FIG. 1, the mirrors 22, 23, 62, and 63 are tilted in the xz plane, and the illumination light beam 4 is focused on the pupil plane of the condenser lens 5.
The passing positions of 1, 42 can be changed in the x direction. Therefore, the pupil of the objective lens 7 is small, as shown in FIG.
In the case where the passing position of the zero-order light beam is far away from the pupil as in (b), the mirrors 22, 23, 62,
By inclining 63, the passing positions of the illumination light beams 41 and 42 are changed, and the light beams 41d 'and 4d' in FIG.
By adjusting the position of 2d ', an optimum resolution can be obtained (FIGS. 2C and 2D). In FIG. 1, the mirrors 22, 23, 62, and 63 are inclined in the xz plane, and the super-resolution is obtained in the x direction in the sample plane.
By inclining in the yz plane, the illumination light beams 41 and 42 are separated in the y direction and pass through the pupil as shown in FIG. 14C, so that a super-resolution can be obtained even in the structure of the sample in the y direction. be able to.

Further, when the pupil radius of the illumination optical system is r, the distance between the centers of the two illumination light beams on the pupil plane of the illumination optical system is 1.5r or more and 2r or less. It is desirable. At this time, optimal super-resolution can be obtained. Fig. 2 shows the distance between the centers of the two illumination beams.
When the distance is less than 1.5r as shown in FIG. 3C, as shown by a region 73f in FIG. 3C, the apparent range through which the diffracted light can pass is smaller than the region 72f in FIG. 3B. , High resolution cannot be obtained.

On the other hand, when the distance between the centers of the two illumination light beams exceeds 2r as shown in FIG. 2D, the range in which the diffracted light can pass apparently is indicated by 74f in FIG. 3D. In this case, the high frequency component is slightly emphasized in the spatial frequency components of the sample, and the contrast of the medium frequency component is suppressed low.

In the configuration of the microscope according to the present invention described above, the polarization beam splitter of the polarization combining optical system is arranged so as to be located near the pupil position of the imaging optical system or near a position conjugate with the pupil. can do. This allows the use of an infinity corrected objective lens.

As shown in FIG. 1, the polarization beam splitter 2
To make the light emitted from one end face of each of the first and second light incident on the same end face again, the polarization conversion element 2 is disposed between the polarization beam splitters 21 and 61 and the mirrors 22, 23, 62 and 63.
4, 25, 64 and 65 are arranged. Polarization conversion element 24,
25, 64, 65 are polarization beam splitters 21, 61
Is an optical element that can change the polarization state such that the polarization direction of light emitted from one end face of the light-emitting element differs from the polarization direction of light incident on the same end face by 90 °. As the polarization conversion elements 24, 25, 64, and 65, a quarter-wave plate or an optical element having the same function as the quarter-wave plate can be used. The direction of the neutral axis of the quarter-wave plate is set at 45 ° with respect to the respective light polarization directions after being reflected or transmitted by the polarizing beam splitter.

Further, an analyzer may be arranged between the polarization combining optical system and the image detection position. Thereby, the contrast of the image can be increased. The analyzer is preferably arranged so that its vibration direction is substantially parallel to the polarizer.

Further, the analyzer may be rotatable. Thereby, the contrast of the image can be adjusted.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the high-resolution microscope of the present invention will be described below with reference to the drawings. (Embodiment 1) FIGS. 5A and 5B show an example of an optical system of an epi-illumination microscope according to the present invention. Here, FIG. 5A shows a polarization separation optical system 51 and a polarization combining optical system 52.
Are arranged in the illumination optical system and the imaging optical system, respectively.
The function and the optical system of the transmission microscope of FIG. 1 are basically the same. FIG. 5B shows a polarization separation / synthesis optical system 5 composed of one polarization separation optical system and one polarization synthesis optical system.
In the case of 3, the polarization separation / synthesis optical system 53 is commonly used by the illumination optical system and the imaging optical system. In any case, the half mirror 27 is disposed behind the objective lens 7 (on the side of the imaging optical system), and the illumination light emitted from the light source 1 and passing through the polarization splitting optical system 51 is reflected by the half mirror 27 so as to be objective. The sample 6 is guided to the lens 7 so that the sample 6 can be illuminated via the objective lens 7. Further, the reflected light from the sample 6 is condensed via the objective lens 7 and forms an image of the sample 6, so that the objective lens 7 is shared by the illumination optical system and the imaging optical system.

The present embodiment will be described in detail with reference to FIG. The illumination light passing through the light source 1, the collector lens 2, the polarizer 3, and the half mirror 27 is polarized and separated.
The light enters the combining optical system 53. Polarization separation / synthesis optical system 53
Illuminates the sample 6 through the quarter-wave plate 26 and the objective lens 7. The scattered light from the sample 6 passes through the objective lens 7, the quarter-wave plate 26, enters and exits the polarization separation / combination optical system 53 again, is reflected by the half mirror 27, and After passing through a rotatable analyzer 9, an image is formed on an image detection position 11 by an imaging lens 10. Here, the vibration directions of the polarizer 3 and the analyzer 9 are set to be substantially parallel. The polarization beam splitter 81 constituting the polarization separation / synthesis optical system 53 is arranged at a position substantially conjugate with the sample 6.

FIG. 6 shows an enlarged view of the optical system between the polarization separation / synthesis optical system 53 and the sample 6. The illumination light beam 40 that has been linearly polarized by the polarizer 3 is separated into reflected light and transmitted light by a polarization beam splitter 81. The polarization directions of the reflected light and the transmitted light are the directions indicated by 91 and 92, respectively, and are orthogonal to each other. The vibration direction of the polarizer 3 is set at 45 ° with respect to the polarization directions indicated by 91 and 92. Similarly, quarter wave plates 84 and 8
5 also has a neutral axis of 45 ° with respect to the directions indicated by 91 and 92.
The direction is set. Polarizing beam splitter 81
Is reflected by the mirror 82, passes through the quarter-wave plate 84 again, and is incident on the polarization beam splitter 81. At this time, since the polarization direction is changed by the quarter-wave plate 84 in a direction orthogonal to the direction indicated by 91, the light transmits through the polarization beam splitter 81 and becomes light having the polarization direction indicated by 93. Similarly, 9 transmitted through the polarizing beam splitter 81
The light in the polarization direction indicated by 2 enters the polarization beam splitter 81 again via the quarter-wave plate 85 and the mirror 83, is reflected, and becomes light in the polarization direction indicated by 94. The directions of the neutral axes of the quarter-wave plate 26 disposed between the polarization separation / synthesis optical system 53 and the objective lens 7 are 93 and 94
Is set to form an angle of 45 ° with the polarization direction indicated by. Therefore, the light in the polarization direction shown by 93 passes through the quarter-wave plate 26, illuminates the sample with the objective lens, and the zero-order light that is not diffracted by the sample passes through the quarter-wave plate 26 again. Then, the light is converted into light having the polarization direction indicated by 94. Similarly, the zero-order light from the sample due to the illumination light of the polarization direction indicated by 94 is converted into light of the polarization direction indicated by 93. The zero-order lights for the pair of illumination light beams separated by the polarization beam splitter 81 return to the respective illumination light paths again, are combined by the polarization separation / combination optical system 53, and are emitted.

When the size of the pupil of the objective lens 7 changes due to the exchange of the objective lens 7 or the like, the inclination angles of the mirrors 82 and 83 of the polarization separation / synthesis optical system 53 are simultaneously changed. The separation interval between the illumination light beams 41 and 42 can be changed. FIG. 7 shows a case where the pupil of the objective lens 7 is smaller than the pupil of the objective lens 7 of the optical system of FIG. In this case, by changing the inclination of the mirrors 82 and 83 in the xz plane, it is possible to obtain an optimum separation interval for the size of the pupil.

In FIGS. 5 and 7, a high resolution can be obtained in the x direction in the sample plane. However, when observing with a high resolution in the y direction, the optical system shown in FIG.
This can be realized by tilting the mirrors 82 and 83 as shown in FIGS. 8B and 8C. That is, the mirror 82 is moved to y-
The mirror 83 is tilted in the xy plane while the mirror 83 is tilted in the z plane. Thereby, the illumination light beams 41 and 42 are separated in the y direction, so that a super-resolution can be obtained in the y direction. Depending on how the mirrors 82 and 83 are tilted, the illumination light beam can be separated even in directions deviating from the x and y axes, so that a high-resolution image can be observed in all directions in the sample plane.

(Embodiment 2) FIG. 9 shows another example of the optical system of the epi-illumination microscope according to the present invention. Example 1
Similarly to the above, the polarization splitting optical system of the illumination optical system and the polarization combining optical system of the imaging optical system are composed of one polarization separating / combining optical system 53, and are commonly used by the illumination optical system and the imaging optical system. doing. The polarization beam splitter of the polarization separation / synthesis optical system 53 is disposed near the pupil position of the objective lens 7 or a position conjugate with the pupil. The illumination light beams 41 and 42 are configured to be parallel to each other. At this time, an infinity correction objective lens can be used as the objective lens 7.

The illumination light that has passed through the light source 1, the collector lens 2, the polarizer 3, and the half mirror 27 enters the polarization separation / combination optical system 53,
The light is separated into reflected light and transmitted light by the polarization beam splitter 81 inside. It is assumed that the reflected light is light in the polarization direction indicated by 91 and the transmitted light is light in the polarization direction indicated by 92. The reflected light exits the polarizing beam splitter 81, is reflected by mirrors 82 and 83, re-enters the polarizing beam splitter 81, and
And becomes the illumination light beam 42 in the polarization direction indicated by 93. Similarly, transmitted light having the polarization direction indicated by 92 is
The light is reflected by the mirrors 83 and 82, reenters the polarization beam splitter 81, passes through the polarization beam splitter 81, and becomes the illumination light beam 41 in the polarization direction indicated by 94. In this embodiment, it is not necessary to arrange a quarter-wave plate between the polarizing beam splitter 81 and the mirrors 82 and 83.

In order to change the separation interval between the illumination light beams 41 and 42, the mirror 82 is moved while the mirror 83 is fixed.
It can be realized by moving in the direction. FIG. 10 shows a case where the size of the pupil of the objective lens 7 is smaller than the pupil of the objective lens 7 of the optical system of FIG. At this time, by moving the mirror 82 in parallel with the −z direction with respect to FIG. 9, an optimal interval between the illumination light beams can be obtained.

(Embodiment 3) FIG. 1 shows an example of a transmission microscope according to the present invention. In FIG. 1, the polarization splitting optical system 51 and the polarization combining optical system 52 are configured by the same optical system, but may be configured by different optical systems. An example is shown in FIG.

In the transmission microscope shown in FIG. 11, light that has passed through the light source 1, the collector lens 2, and the polarizer 3 enters the polarization separation optical system 51, is emitted, passes through the condenser lens 5, and illuminates the sample 6. . The scattered light from the sample 6 passes through the objective lens 7 and is
Is emitted to the analyzer 9 and the imaging lens 1
0, and the image is formed at the image detection position 11. The polarization separation optical system 51 is the same optical system as the polarization separation optical system 51 of the transmission microscope shown in FIG. On the other hand, the polarization combining optical system 52
Is the same optical system as the polarization separation / combination optical system 53 of the epi-illumination microscope shown in FIG.

In FIG. 1, the polarizing beam splitter 21 and the polarizing beam splitter 61 are respectively provided on the sample 6 on the front side of the condenser lens 5 and on the rear side of the objective lens 7.
In FIG. 11, the polarization beam splitter 61 constituting the polarization combining optical system 52 is disposed.
Is disposed near the pupil position of the objective lens 7 or a position conjugate with the pupil.

Although the high-resolution microscope of the present invention has been described based on the embodiments, the present invention is not limited to these embodiments, and various modifications can be made.

The above high-resolution microscope of the present invention can be configured, for example, as follows. [1] In a microscope including a collector lens that guides light from a light source to an illumination optical system, an illumination optical system that illuminates a sample, and an objective lens that captures diffracted light from the sample, between the collector lens and the illumination optical system A polarization separation optical system for separating an incident light beam into two illumination light beams having polarization directions orthogonal to each other, and diffracted light beams having different polarization directions diffracted from the sample by the illumination light beam between an objective lens and an image detection position. The polarization splitting optical system is arranged such that the polarization splitting optical system includes a polarizing beam splitter and a mirror, and the mirror is such that light incident on the polarization splitting optical system passes through the polarizing beam splitter twice. The two illumination light beams pass through different positions on the pupil plane of the illumination optical system, and one of the illumination light beams is separated from the same light beam. The pair of light beams is configured to irradiate the same point on the sample surface, and the polarization combining optical system includes a polarizing beam splitter and a mirror, and the mirror is configured to convert the light incident on the polarization combining optical system into the polarization beam. A high-resolution microscope configured to pass through a splitter twice.

[2] An epi-illumination microscope using the objective lens also as the illumination optical system, wherein the objective lens is between the collector lens and the polarization separation optical system or between the polarization separation optical system and the objective lens. 2. The high-resolution microscope according to claim 1, further comprising a light beam splitter for separating an illumination light beam and an imaging light beam.

[3] The light beam splitter is disposed between the collector lens and the polarization separation optical system, and the polarization separation optical system and the polarization combination optical system are configured as a common polarization separation / combination optical system. 3. The high-resolution microscope according to claim 2, wherein a polarization conversion element is disposed between the polarization separation / synthesis optical system and the objective lens.

[4] The polarization splitting optical system is configured so that, when the mirror is tilted, the polarization splitting optical system is positioned on the pupil plane of the illumination optical system.
4. The high-resolution microscope according to any one of the above items 1 to 3, wherein a position at which two illumination light beams pass is changed.

[5] The polarized light separating optical system moves the mirror on the pupil plane of the illumination optical system by moving the mirror.
4. The high-resolution microscope according to any one of the above items 1 to 3, wherein a position at which two illumination light beams pass is changed.

[6] When the pupil radius of the illumination optical system is r, the distance between the centers of the two illumination light beams on the pupil plane of the illumination optical system is 1.5r or more and 2r or less. The high-resolution microscope according to any one of the above items 1 to 5, wherein:

[7] Any of the above items 1 to 6, wherein the polarization beam splitter of the polarization combining optical system is arranged near a pupil position of the imaging optical system or near a position conjugate with the pupil. 2. The high-resolution microscope according to claim 1.

[8] The high-resolution microscope according to any one of [1] to [7], wherein a polarization conversion element is disposed between the polarization beam splitter and the mirror.

[0044]

[9] The high-resolution microscope according to the above [3] or [8], wherein the polarization conversion element is a quarter-wave plate or an optical element having the same function as a quarter-wave plate.

[10] The high-resolution microscope according to any one of [1] to [9], wherein an analyzer is arranged between the polarization combining optical system and an image detection position.

[11] The high-resolution microscope according to the item 10, wherein the analyzer is rotatable.

[12] In a microscope having a collector lens for guiding light from a light source to a sample and an objective lens for illuminating the sample and taking in diffracted light from the sample, a microscope is provided between the collector lens and the objective lens. A polarization separation optical system that separates an incident light beam into two illumination light beams whose polarization directions are orthogonal to each other, and combines diffracted light beams having different polarization directions diffracted from the sample by the illumination light beam between an objective lens and an image detection position. A polarizing beam splitter is disposed between the objective lens and the beam combining optical system, the polarization splitting optical system includes a polarizing beam splitter and a mirror, and the mirror is separated from the collector lens. The polarization splitting / synthesizing optical system is configured such that the incident light passes through the polarizing beam splitter twice, and the two illumination light beams are directed to the objective lens. A pair of light beams that pass through different positions on the pupil plane of the lens, and are separated from the same light beam in each of the illumination light beams, irradiate the same point on the sample surface, A high resolution microscope, wherein the system includes a polarizing beam splitter and a mirror, wherein the mirror is configured such that light incident on the polarization combining optical system passes twice through the beam splitter.

[13] In a microscope having a collector lens for guiding light from a light source to a sample and an objective lens for illuminating the sample and taking in diffracted light from the sample, a microscope is provided between the collector lens and the objective lens. And a polarization separation / combination optical system that separates an incident light beam into two illumination light beams having polarization directions orthogonal to each other and causes the light beam to enter the objective lens, and combines diffracted light beams having different polarization directions diffracted from a sample by the illumination light beam. A light splitter is arranged between the collector lens and the polarization splitting / combining optical system,
The polarization separation / synthesis optical system includes a polarization beam splitter and a mirror, and the mirror is configured such that incident light from the collector lens to the polarization separation / synthesis optical system passes through the polarization beam splitter twice, The two illumination light beams pass through different positions on the pupil plane of the objective lens, and in each illumination light beam, a pair of light beams separated from the same light beam illuminate the same point on the sample surface, A high-resolution microscope, wherein the diffracted light diffracted from the light beam passes through the beam splitter twice.

[0049]

As is apparent from the above description, according to the present invention, it is possible to relatively easily realize a microscope having a high resolution exceeding the resolution of a normal microscope without requiring a complicated mechanism. it can. Further, it is possible to easily adjust the resolving power and the direction in which the super-resolution is obtained, and it is possible to realize a high-resolution microscope in which the contrast hardly deteriorates.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a transmission microscope according to the present invention.

FIG. 2 is a diagram illustrating a relative positional relationship between a pupil of an objective lens and a region through which an illumination light beam passes.

FIG. 3 is a view showing an apparent diffracted light passage area corresponding to FIG. 2;

FIG. 4 is a diagram showing a region through which diffracted light corresponding to illumination light passes.

FIG. 5 is a diagram illustrating a configuration of an epi-illumination microscope according to the first embodiment.

FIG. 6 is an enlarged view of a part of FIG. 5;

FIG. 7 is a diagram showing that the separation interval of the illumination light beam can be adjusted by tilting the mirror.

FIG. 8 is a diagram showing that the direction of separation of the illumination light beam can be adjusted by tilting the mirror.

FIG. 9 is a diagram illustrating a configuration of an epi-illumination microscope according to a second embodiment.

FIG. 10 is a diagram showing that the separation interval of the illumination light beam can be adjusted by moving the mirror in parallel.

FIG. 11 is a diagram illustrating a configuration of a transmission microscope according to a third embodiment.

FIG. 12 is a diagram illustrating a conventional Lukosz method.

FIG. 13 is a diagram illustrating a conventional method such as Lohmann.

FIG. 14 is a diagram showing a light beam of zero-order light from a sample passing through a pupil plane of an objective lens in the method of Lohmann et al.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Collector lens 3 ... Polarizer 5 ... Condenser lens 6 ... Sample 7 ... Objective lens 7a, 7a '... Pupil of an objective lens 9 ... Analyzer 10 ... Imaging lens 11 ... Image detection position 21, 61, 81 ... Polarization Beam splitters 22, 23, 62, 63, 82, 83: mirrors 24, 25, 64, 65: polarization conversion elements (quarter wavelength plates) 26, 84, 85: quarter wavelength plates 27: half mirrors 40, 41, 42: illumination light beams 41f, 42f: diffracted light passing areas 41d, 42d, 41d ', 42d': 0th-order diffracted light beams 51: polarized light separating optical system 52: polarized light combining optical system 53: polarized light separating / combining Optical system 71f, 72f, 73f, 74f: Apparent area through which diffracted light can pass 91, 92, 93, 94: Polarization direction of linearly polarized light

Claims (3)

[Claims] 1. A microscope comprising a collector lens for guiding light from a light source to an illumination optical system, an illumination optical system for illuminating a sample, and an objective lens for taking in diffracted light from the sample, comprising: a collector lens and an illumination optical system. Between the objective lens and the image detection position, the polarization direction diffracted from the sample by the illumination light beam is different between the objective lens and the image detection position. A polarization combining optical system for combining diffracted light is disposed, wherein the polarization splitting optical system includes a polarizing beam splitter and a mirror, and the mirror passes light that has entered the polarization splitting optical system twice through the polarizing beam splitter. The two illumination light beams pass through different positions on the pupil plane of the illumination optical system, and are separated from the same light beam in the respective illumination light beams. The pair of light beams is configured to irradiate the same point on the sample surface, the polarization combining optical system includes a polarizing beam splitter and a mirror, the mirror is a light incident on the polarization combining optical system, A high-resolution microscope configured to pass through a polarizing beam splitter twice. 2. An epi-illumination microscope using the objective lens also as the illumination optical system, wherein the objective lens is between the collector lens and the polarization separation optical system or between the polarization separation optical system and the objective lens. And a beam splitter for separating the illumination light beam and the image forming light beam from each other.
High resolution microscope as described. 3. The polarization splitting optical system is characterized in that the position of the two illumination light beams on the pupil plane of the illumination optical system changes when the mirror is tilted. The high-resolution microscope according to claim 1 or 2, wherein