MICROSCOPE

• US 20100142038A1
• Filed: 06/30/2006
• Published: 06/10/2010
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nara Institute of Science and Technology, National University Corporation, Nikon Corporation
• Inventors: Matsui, Kumiko, Kawahito, Takashi, Sugiura, Tadao, Yasaka, Katsuhiko
• Granted Patent: US 7,957,058 B2
• Time in Patent Office: Days
• US Class Current: 359/381
• CPC Class Codes: G02B 21/082 for incident illumination only
• CPC Class Codes: G02B 5/3066 involving the reflection of light at a particular angle of incidence, e.g. Brewster's angle

Abstract

A microscope for introducing light from a light source via an objective lens to a sample so that a user observes the sample via the objective lens includes: a minute opening arranged in an optical path between the light source and the objective lens and on a focal plane of the image side of the objective lens or at a position conjugate with its conjugate plane; position adjusting means for adjusting the position of the minute opening so that the light from the light source via the minute opening is incident to the sample at the Brewster'"'"'s angle; an polarizing element arranged in the optical path between the light source and the objective lens for extracting rectilinear polarized light from the light from the light source and applying the rectilinear polarized light to the sample.

Claims

1. A microscope that illuminates a sample with light from a light source through an objective lens and makes it possible to observe the sample through the objective lens, the microscope comprising:

a minute aperture that is disposed in an optical path between the light source and the objective lens and disposed at a position of an image side focal plane of the objective lens or a position conjugate therewith;

a position adjustment member that adjusts the position of the minute aperture so as to make light from the light source incident on the sample with the Brewster angle through the minute aperture; and

a polarizer that is disposed in the optical path between the light source and the objective lens, produces linearly polarized light, and illuminates the sample with the linearly polarized light.

2. The microscope according to claim 1, wherein the position adjustment member adjusts the position of the minute aperture in a direction perpendicular to an optical axis so as to make the light from the light source incident on the sample with an angle within a given angular range including the Brewster angle.

3. The microscope according to claim 1, wherein the position adjustment member adjusts the position of the minute aperture in a rotation direction around an optical axis so as to make the light from the light source incident on the sample with an angle within a given angular range including the Brewster angle.

4. The microscope according to claim 1, wherein the polarizer produces p-polarized light or s-polarized light as linearly polarized light.

5. The microscope according to claim 2, wherein the position adjustment member adjusts the position of the minute aperture in a direction perpendicular to the optical axis so as to make the light from the light source incident on the sample with an angle causing total reflection, and enables to change the observation with the angle of incidence on the sample from the angle causing total reflection to the Brewster angle.

6. The microscope according to claim 1, further comprising:

an aperture stop for an episcopic illumination, having a larger aperture than the minute aperture; and

a switching member that switches from the minute aperture to the aperture stop to be disposed into the optical path.

7. The microscope according to claim 2, wherein when a cover glass on which a metal thin film is formed on a surface contact with the sample, the position adjustment member adjusts the position of the minute aperture in a direction perpendicular to the optical axis so as to make the light from the light source incident on the sample with an angle causing surface plasmon resonance between the sample and the metal thin film.

8. The microscope according to claim 1, wherein the minute aperture is a pinhole or a slit having an arc shape centered around the optical axis.

9. The microscope according to claim 1, wherein the minute aperture is disposed a plurality of numbers on a circumference of a circle centered on the optical axis.

10. The microscope according to claim 1, wherein the minute aperture disposed rotatably around the optical axis.

17. The microscope according to claim 1, further comprising:

a quarter-wave plate that is removably disposed in the optical path between the polarizer and the objective lens, and is rotatable around the optical axis; and

an analyzer that is removably disposed in the optical path and is rotatable around the optical axis;

wherein upon setting the quarter-wave plate and the analyzer into the optical path, and setting the polarizer such that among the illumination light on the sample only linearly polarized light having a plane of polarization of 45 degrees with respect to the plane of incidence of the illumination light from the light source on the sample is transmitted, ellipsometry of the sample can be carried out.

11. A microscope that illuminates a sample with laser light from a laser light source through an objective lens and makes it possible to observe the sample through the objective lens, the microscope comprising:

a polarizer that is disposed on an optical path between the laser light source and the objective lens and produces linearly polarized light;

wherein the laser light source is disposed such that a converging point of the laser light is disposed at a position conjugate with a pupil of the objective lens, and the laser light is positioned where laser light is incident on the sample with a Brewster angle

12. The microscope according to claim 11, wherein the laser light source can be adjusted the converging point thereof in a direction perpendicular to an optical axis so as to make the laser light incident on the sample with a Brewster angle.

13. The microscope according to claim 11, wherein the laser light source can be adjusted to move an exit point of the laser light in a direction perpendicular to an optical axis so as to make the laser light incident on the sample with an angle causing a total reflection, and enables to switch the observation with an angle of incidence on the sample from the angle causing total reflection to the Brewster angle.

14. The microscope according to claim 12, wherein when a cover glass on which a metal thin film is formed on a surface contact with the sample, the laser light source can be adjusted to move the exit position of the laser light in a direction perpendicular to the optical axis so as to make the laser light incident on the sample with an angle causing surface plasmon resonance between the sample and the metal thin film.

15. The microscope according to claim 11, wherein the laser light source has a plurality of exit points of the laser light on a circumference of a circle centered on the optical axis.

16. The microscope according to claim 11, wherein the laser light source has an exit point of the laser light rotatable around the optical axis.

24. The microscope according to claim 13, wherein when a cover glass on which a metal thin film is formed on a surface contact with the sample, the laser light source can be adjusted to move the exit position of the laser light in a direction perpendicular to the optical axis so as to make the laser light incident on the sample with an angle causing surface plasmon resonance between the sample and the metal thin film.

18. A microscope that illuminates a sample with light from a light source through an objective lens and makes it possible to observe the sample through the objective lens, the microscope comprising:

a minute, arc-shaped aperture that is disposed in an optical path between the light source and the objective lens in the vicinity of an image side focal plane of the objective lens or a conjugate plane thereof, and makes the light from the light source incident on the sample with substantially Brewster angle; and

a polarizer that is disposed in the optical path between the light source and the objective lens and provides linearly polarized light from light from the light source,

wherein the minute, arc-shaped aperture satisfies the following conditional expressions;

δ

r≦

0.06×

f

φ

≦

20°

where δ

r denotes a radial width of the minute, arc-shaped aperture, f denotes a focal length of the objective lens, and φ

denotes a central angle of the minute, arc-shaped aperture.

19. The microscope according to claim 18, further comprising:

an aperture stop for an episcopic illumination, having a larger aperture than the minute, arc-shaped aperture; and

a switching member that switches from the minute, arc-shaped aperture to the aperture stop to be disposed into the optical path.

20. The microscope according to claim 18, further comprising:

a plurality of minute, arc-shaped apertures disposed on a circumference of a circle centered on the optical axis; and

a plurality of polarizers disposed on the respective minute, arc-shaped apertures;

wherein each polarizer is parallel, perpendicular, or 45 degrees with respect to a line connecting substantially the center of each corresponding minute aperture and the optical axis.

21. The microscope according to claim 20, wherein each of the plurality of minute, arc-shaped apertures is independently movable in a radial direction thereof.

22. The microscope according to claim 18, wherein the minute, arc-shaped aperture or the plurality of minute, arc-shaped apertures and the polarizers are rotatably disposed around the optical axis at high speed.

23. The microscope according to claim 18, wherein a rotating diffuser is disposed in the optical path between the light source and the objective.