JPH05296842A - Confocal polarization scanning microscope - Google Patents

Abstract

PURPOSE:To obtain a confocal scanning microscope capable of observing the polarized state of light and using an optical fiber. CONSTITUTION:The light from a light source 1 is collimated by a lens 10 and turned to a linearly polarized light by a polarizer 31. The light in the linearly polarized state passes through a beam splitter 20 and is condensed by a lens 11 to an end face 401 of an optical fiber 40 which preserves the polarized light. The light projecting from the other end face 402 of the fiber 40 is condensed as a convergent light onto the surface of a sample 80 by lenses 13 and 12. The reflecting light from the sample 80 is, through the lenses 12, 13, the end face 402, the fiber 40, the end face 401 and the lens 11, reflected by the beam splitter 20 and displayed at a display device 60 through an analyzer 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarization confocal scanning microscope suitable for detecting changes in the polarization state of response light from a sample.

[0002]

A conventional polarization scanning microscope is realized by illuminating a sample with polarized light and observing the sample through an analyzer. The configuration of the optical system in this device is described in Optical Technology Handbook (edited by Kubota et al., Asakura Shoten, Showa 5).
5 years), page 855.

As an example of a confocal microscope using an optical fiber, there is JP-A-3-87804. In the above example, the light source, the photodetector, and the microscope are connected to each other by flexible optical fibers so that they can be provided at arbitrary positions.

[0004]

In the above-mentioned prior art, since a general optical fiber having an optically circular core is used, the polarization plane easily rotates due to bending or vibration from the outside. Storage is poor and it is very difficult to analyze the polarization state.

An object of the present invention is to obtain an apparatus capable of observing the polarization dependence of a sample in a confocal microscope using an optical fiber.

[0006]

The above-mentioned object is to provide a light source, a polarizer for converting the light from the light source into a specific polarization state, a polarization-maintaining optical fiber, and a polarization-maintaining optical fiber for maintaining the polarization state of the light. From the sample, an optical system for entering the fiber, an optical system for collecting the light emitted from the fiber, a sample arranged at the focal point of the optical system, a scanning mechanism for scanning the sample or the convergent light, An optical system that collects response light such as scattered light or reflected light, Raman scattered light, or fluorescence on the emission end face of the same fiber, and an optical element that reflects a part or all of the response light that has passed through the fiber, An analyzer provided in the optical path of the reflected response light, a photodetector for detecting light emitted from the analyzer, an irradiation location of light on the sample, and an output of the photodetector are displayed in association with each other. With a display device Ri is achieved.

[0007]

The light in the linearly polarized state emitted from the light source and passing through the polarizer is condensed by the lens on the end face of the polarization-maintaining optical fiber. The light propagating through the polarization-maintaining optical fiber and emitted from the other end face becomes light in a stable linear polarization state by adjusting the direction of the principal axis of the fiber. The emitted light is condensed as convergent light on the sample through the optical system, and the condensed light scans the sample on the stage. The scattered light or reflected light from the sample is incident on the exit end of the polarization-maintaining optical fiber through an optical system, and the light emitted from the entrance end of the fiber is polarized depending on the surface state of the sample. Changes, and only light of a specific polarization direction is reflected by the beam splitter and enters the photodetector by the analyzer. Since the output of the photodetector is displayed in association with the scanning position of the sample, it is possible to display images in various polarization directions by rotating the polarization axis of the analyzer. A dark field microscope can be realized by setting the polarization axis of the analyzer perpendicular to the polarization axis of the polarizer.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. 1 is a schematic configuration diagram showing a first embodiment of a polarization confocal scanning microscope according to the present invention, FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention. It is a schematic block diagram.

First Embodiment In FIG. 1 showing a first embodiment of the present invention, light from a light source 1 is collimated by a lens 10. When the degree of polarization of the light from the light source 1 is small, a polarizer 31 is inserted to make linearly polarized light. The linearly polarized light is beam splitter 20.
And the polarization-preserving optical fiber 4 is transmitted by the lens 11.
It is focused on the end surface 401 of 0. It is assumed that the light emitted from the other end face 402 of the fiber 40 is also in a linearly polarized state by adjusting the direction of the principal axis of the polarization-maintaining optical fiber 40. The emitted light is condensed by the lenses 13 and 12 on the surface of the sample 80 as converged light. The sample 80 is placed on the stage 90, and is scanned in the x, y, and z directions by the scanning mechanism of the stage 90. The scattered light or the reflected light from the sample 80 is incident on the end face 402 of the polarization-maintaining optical fiber by the condensing optical system including the lenses 12 and 13. The light emitted from the end face 401 has its polarization direction changed depending on the surface state of the sample 80. The end face 40
The emitted light from 1 is reflected by the beam splitter 20, the reflected light passes through the analyzer 32, the light of a specific polarization direction is selected, and enters the photodetector 50. The output from the photodetector 50 is displayed on the display device 60 in association with the scanning position of the sample 80. By rotating the polarization axis of the analyzer 32, images of various polarization directions are displayed on the display device 6.
The dark field microscope can be realized by setting it in the direction perpendicular to the polarization axis of the polarizer 31. In the present embodiment, the example in which the sample 80 is scanned by the stage 90 is shown, but a galvanometer mirror, an AO deflector or the like may be used between the lenses 12 and 13 to scan the laser beam.

Second Embodiment In the first embodiment, the beam splitter 20 is used to allow the light emitted from the polarizer 31 to pass therethrough and to be incident on the end face 401 of the polarization-maintaining optical fiber 40.
The light reflected on the surface of No. 0, transmitted through the fiber 40, and emitted again is reflected and made incident on the analyzer 32. However, as in the second embodiment shown in FIG. Even if the optical fiber coupler 41 described above is used, the same effect as that of the first embodiment can be obtained.

Third Embodiment In a third embodiment shown in FIG. 3, a quarter-wave plate 33 is inserted in the optical path, and an end face 4 of a polarization-maintaining optical fiber 40 is inserted.
The linearly polarized light emitted from 02 is converted into a circularly polarized light. If the sample 80 is a mirror surface, the light reflected from the sample 80 and returning to the quarter-wave plate 33 is in the circular polarization state in which the light is rotated in the direction opposite to the direction of the emitted light. The polarization direction of the light transmitted through the plate 33 is orthogonal to the polarization direction of the incident light. If sample 8
When 0 is not a mirror surface state, the reflected light may be in an elliptically polarized state, and the light transmitted through the wave plate 33 may have an amplitude component in the same direction as the polarization direction of the incident light. If the polarization axis of the analyzer 32 is set in the same direction as the polarization axis of the polarizer 31, the above component will enter the photodetector 50. When the image is formed using the detection signal of the photodetector 50, a dark field image is formed.

The beam splitter 20 in FIG. 1 showing the first embodiment and FIG. 3 showing the third embodiment.
Plays a role of transmitting the light from the light source 1 and reflecting the detection light incident on the photodetector 50, but the effect of the invention does not change even if the positions of the light source 1 and the photodetector 50 are replaced. .

[0013]

As described above, the polarization confocal scanning microscope according to the present invention comprises a light source, a polarizer for converting the light from the light source into a specific polarization state, a polarization-maintaining optical fiber, and a light of the polarization state. An optical system for making the polarization-preserving optical fiber incident on the optical system, an optical system for condensing light emitted from the fiber, a sample arranged at a focal position of the optical system, and a scan for scanning the sample or the converged light. Mechanism, an optical system that collects the response light such as scattered light or reflected light from the sample, Raman scattered light, or fluorescence on the emission end face of the same fiber, and part or all of the response light that has passed through the fiber. An optical element that reflects light, an analyzer provided in the optical path of the reflected response light, a photodetector that detects light emitted from the analyzer, a light irradiation location in the sample, and an output of the photodetector. The table that displays By providing a device, a polarizing confocal scanning microscope is implemented using the polarization maintaining optical fiber. The above method uses the end face of the polarization-maintaining optical fiber as a substantial light source aperture of the confocal scanning microscope and at the same time as a substantial aperture of the photodetector.
The end face of the fiber is automatically in the confocal position. Therefore, the confocal optical system can be easily constructed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a polarization confocal scanning microscope according to the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention.

[Explanation of symbols]

1 Light Source 20 Beam Splitter (Optical Element that Reflects Part or All of Response Light) 31 Polarizer 32 Analyzer 40 Polarization Preserving Optical Fibers 401, 402 Optical Fiber End Face 41 Fiber Coupler 50 Photodetector 60 Display Device 80 Sample

Claims (3)

[Claims] 1. A light source, a polarizer for converting light from the light source into a specific polarization state, a polarization-maintaining optical fiber, and an optical system for causing light in the polarization state to enter the polarization-maintaining optical fiber. An optical system that collects the light emitted from the fiber, a sample that is arranged at the focal point of the optical system, a scanning mechanism that scans the sample or the converged light, and scattered light or reflected light or Raman from the sample. An optical system that collects response light such as scattered light or fluorescence on the emission end face of the same fiber, an optical element that reflects a part or all of the response light that has passed through the fiber, and an optical path of the reflected response light. A polarization detector provided with an analyzer, a photodetector that detects light emitted from the analyzer, and a display device that displays the irradiation location of light on the sample and the output of the photodetector in association with each other. Focus scanning microscope. 2. The polarization confocal scanning microscope according to claim 1, wherein the analyzer rotates the polarization axis by 90 degrees with respect to the polarization axis of the polarizer to obtain a dark field image. 3. The polarization confocal scanning microscope according to claim 1, wherein a fiber coupler using a polarization-maintaining optical fiber is used as the optical element that reflects a part or all of the response light.