KR20070029942A - Beam splitting method with a mirror and optical device thereof - Google Patents

Abstract

A beam splitting method using a mirror and an optical device using the method are provided to apply for a wide wavelength band independently of a wavelength by using the reflection characteristic of the mirror and to cut down the cost by simplifying the structure. In a beam splitting method, a plane mirror(10) comprising a light reflecting unit(12) and a light transmitting unit(14) is inclined at a predetermined angle to the incident beam. One incident beam is split into two by reflecting the beam incident to the light reflecting unit and transmitting the beam incident to the light transmitting unit. The reflecting unit corresponds to the center portion of the plane mirror and the transmitting unit corresponds to the peripheral portion of the plane mirror.

Description

Beam splitting method with a mirror and optical device thereof

1 is a conceptual diagram for explaining the role of the light splitter

2 is a conceptual diagram of a prior art cube-type beam splitter

3 is a conceptual diagram of a semi-plated mirror ray separator of the prior art

4 is a conceptual diagram of a prior art color sorting beam splitter

5 is a plan view and a side view of a mirror used in the beam separation method according to the first embodiment of the present invention;

6 is a conceptual diagram illustrating a light beam splitting method according to a first embodiment of the present invention.

7 is a conceptual diagram of an optical apparatus using the apparatus using the light beam separation method according to the first embodiment of the present invention.

FIG. 8 is a graph showing the point spread function (PSF) of light rays illuminated on a specimen of a device using the light beam separation method according to the first embodiment of the present invention.

9 is a plan view and a side view of a mirror used in the beam separation method according to the second embodiment of the present invention;

10 is a conceptual diagram illustrating a light beam splitting method according to a second embodiment of the present invention.

11 is a conceptual diagram of an optical apparatus using the apparatus using the light beam separation method according to the second embodiment of the present invention.

<Explanation of symbols in the drawings>

10, 10 ′: beam separation mirror 12, 12 ′: coating part

14, 14 ′: non-coated portion 16, 16 ′: coated thin film

20: lighting device 30: light collecting device

40: test piece 50: detection device

100: Ray Separator

110: cube-type ray separator 112, 114: prism

116 resin

120: semi-plated mirror ray separator 122: glass

124: metal thin film

130: color screening light separator 132: glass

134: multilayer thin film

The present invention relates to a light beam separation method using a mirror and an optical device using the same, and more particularly, in an optical system that must separate the illumination light and the detection light, such as a general reflection / fluorescence microscope, confocal microscope, pickup system, etc. It relates to a method for separating the light beam using the optical device using the same.

The beam splitter serves to split one ray into two rays. 1 illustrates the role of the beam splitter. As shown in FIG. 1, the beam splitter 100 installs a beam splitter on a path through which a beam proceeds, and separates one incident beam (solid line) into two beams (dashed lines and dashed lines). Such light splitters are mainly used in optical systems such as interferometers, microscopes, and cameras.

Conventional beam splitters include cube-shaped beam splitters, semi-plated mirror beam splitters, and color screening mirror beam splitters.

2 is a conceptual diagram of a cube-type beam splitter 110 that is most commonly used. Cube-shaped beam splitter 110 is made by joining two isosceles right-angled triangular prisms 112 and 114 with a resin 116 such as Canadian balsam. Incident light (solid line) is incident on the first prism 112, and a part of the light of a specific wavelength (dashed line) is transmitted through the resin 116 at the interface between the first prism 112 and the second prism 114, and the rest is transmitted. Some (dotted lines) reflect. The cube-shaped beam splitter 110 has a wavelength that can be used according to the thickness of the resin 116 and its efficiency is determined. Therefore, this is a limitation in applications in optical systems in which a wide range of light rays are used, such as a fluorescence microscope.

3 is a conceptual diagram of a half-silvered mirror ray splitter 120 which is another type of light splitter. Semi-plated specular light splitter 120 is fabricated by coating a thin metal film 124 over flat glass 122. The metal film 124 is made up of several tens of molecules thick, and a part of light rays (solid lines) incident at 45 ° at a specific wavelength is transmitted through the metal film (dashed lines) and the other part is reflected by the metal film (dashed lines). The half-plated specular light splitter 120 has a limited usable wavelength and efficiency depending on the thickness of the metal film 124. Therefore, this is a limitation in applications in optical systems in which a wide range of light rays are used, such as a fluorescence microscope.

4 is a conceptual diagram of a chromatic light splitter 130 which is another type of light splitter. The color screening mirror is manufactured by coating the multilayer thin film 134 on the flat glass 132. When light rays (solid line) of two or more different wavelength bands are incident at 45 °, light rays of a specific wavelength are reflected (dashed lines) by an interference effect in the thin film 134, and light rays of different wavelengths are transmitted (dashed lines). Color-selective light splitter 130 has to be replaced according to the wavelength of the light beam used due to the characteristics of reflection and transmission depending on the wavelength, the efficiency is generated depending on the coating of the multilayer thin film 134 used.

As described above, the conventional beam splitter has a limitation in using in a wide wavelength range because its transmission and reflection characteristics change depending on the wavelength, and there is a problem in that the structure is not simple.

Meanwhile, Stefan W. Hell et al., “Annular aperture two-photon excitation microscopy”, Optical communications, pp. 20-24, 1995, it is disclosed that the resolution of a microscope is improved by an apodization effect (or tapering effect) in a confocal microscope. In this case, a circular stop having a diameter of 85% of the objective lens diameter is installed in front of the objective lens for the apodization effect, and the light beam is passed through an annular aperture to improve the resolution.

This stop is expected to lead to an improvement in resolution not only in confocal microscopy but also in other optical devices. However, when the stop is installed to induce the improvement of resolution by the apodization effect, the structure is complicated by adding a stop to an existing component, and it may be difficult to configure the optical system in a small size.

An object of the present invention is to provide a light separation method and apparatus using a mirror that is independent of the wavelength and has a simple structure compared to the conventional light splitter by overcoming the influence of the wavelength used by the conventional light splitter. At the same time, to provide a beam separation method and apparatus using a mirror that can improve the optical resolution by the apodization effect.

In order to achieve the object of the present invention described above, the present invention uses a planar mirror composed of a reflecting portion for reflecting light and a transmitting portion for transmitting light, by tilting at a predetermined angle with respect to the incident light beam. The light beam incident on the reflector is reflected and the light beam incident on the transmissive part is transmitted to provide a beam separation method using a mirror, characterized in that one incident light beam is separated into two light beams.

이다.In this case, it is possible that the reflecting part is the center of the flat mirror and the transmitting part is the periphery of the flat mirror, or the reflecting part is the periphery of the flat mirror and the transmitting part is the center of the flat mirror. In this case, when the plane mirror is inclined at a predetermined angle θ with respect to the incident light beam, the plane mirror and the reflecting or transmissive part are ellipses having a ratio of the length of the major axis to the minor axis being 1 / cosθ, and the plane perpendicular to the path of the incident light beam. When projected onto the plane mirror and the reflecting or transmissive portion is preferably projected in a circle. More preferably, the predetermined angle is 45 °, and the length of the major axis relative to the length of the minor axis is

to be.

The above-mentioned reflector may be made of glass coated with a reflective coating thin film, and the transmissive part may be made of glass or an empty space not coated with a reflective coating thin film.

In another aspect, the present invention, the lighting device including a light source; A planar mirror comprising a reflector for reflecting light and a transmissive part for transmitting light, wherein the planar mirror is inclined at a predetermined angle with respect to the illumination beam emitted from the illumination device; A light collecting device including a convex lens or a concave mirror; Specimens for fixing the object to be observed; And a detection device for detecting the light beam from the observation target, wherein the light beam from the lighting device is divided into two light beams in the light beam splitting device, and one of the two light beams separated from the light beam travels to the light collecting device. The specimen is focused on the specimen by a condenser, and the reflection or fluorescent light from the specimen passes through the concentrator and is split into two beams in a beam splitter and two beams separated from the reflected or fluorescent beam. One provides an optical device characterized in that it proceeds to a detection device.

이다. In this case, it is possible that the reflecting part is the center of the flat mirror and the transmitting part is the periphery of the flat mirror, or the reflecting part is the periphery of the flat mirror and the transmitting part is the center of the flat mirror. In this case, when the plane mirror is inclined at a predetermined angle θ with respect to the incident light beam, the plane mirror and the reflecting or transmissive part are ellipses having a ratio of the length of the major axis to the minor axis being 1 / cosθ, and the plane perpendicular to the path of the incident light beam. When projected onto the plane mirror and the reflecting or transmissive portion is preferably projected in a circle. More preferably, the predetermined angle is 45 °, and the length of the major axis relative to the length of the minor axis is

to be.

In this case, the illumination device is in line with the beam splitting device, the light collecting device and the specimen and the detection device is located in the path of the beam reflected from the specimen or reflected by the beam splitting device among the fluorescent beams, or the detection device is a beam splitting device, the light collecting device. Located in alignment with the device and the specimen, the illumination device may configure the optical device such that the light beam reflected by the beam splitter of the illumination beam from the illumination device is directed to the specimen.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]

5 shows a beam splitting mirror 10 used in the first embodiment of the present invention.

The mirror 10 is a planar mirror, and its shape and inclination with respect to the incident light beam may be adjusted according to the characteristics of the incident light beam and the transmission light beam and the reflected light beam to be described later. In this embodiment, the case where the incident light beam is circular and the transmitted light beam and the reflected light beam are vertically separated will be described as an example. When the incident light beam is circular having a radius of 'a', when the plane mirror 10 is inclined at an angle θ with respect to the incident light beam, the plane mirror 10 has a short axis length r _b of 'a' and The length r _a must be an ellipse of 'a / cosθ'.

인 타원 모양이다. 도 6에서 도시되는 바와 같이, 평면 거울(10)은 평면 거울(10)로의 입사 광선에 대하여 45° 기울어지게 설치된다. 그러므로 평면 거울(10)이 입사 광선에 수직인 면에 투영되었을 때, 단축의 길이(r_b)는 변하지 아니하고 장축의 길이(r_a)는

로 작아지게 되어, 타원 거울(10)은 반지름이 단축의 길이(r_b)와 같은 원으로 투영된다. 여기에서, 타원 거울(10)이 투영된 원의 반지름(r_b)는 입사 광선의 구경과 같다.As an example an example in which the planar mirror 10 is tilted 45 ° with respect to the incident light is shown in FIG. 6. The planar mirror 10 has a ratio of the length r _a of the major axis to the length r _b of the minor axis.

It is an ellipse shape. As shown in FIG. 6, the planar mirror 10 is installed at an inclination of 45 ° with respect to the incident light beam to the planar mirror 10. Therefore, when the plane mirror 10 is projected on a plane perpendicular to the incident light beam, the length of the short axis r _b does not change and the length of the long axis r _a is

The ellipsoidal mirror 10 is projected onto a circle whose radius is equal to the length of the short axis r _b . Here, the radius r _b of the circle on which the elliptical mirror 10 is projected is equal to the diameter of the incident ray.

The central portion of the planar mirror 10 is a coating portion 12 which is coated with a coating thin film 16 on glass, and the periphery of the flat mirror is a non-coating portion which is not coated with a coating thin film 16 on glass. (14). The coating thin film 16 may use a conventional mirror coating material capable of total reflection regardless of the wavelength of the incident light.

인 타원이며, 평면 거울(10)이 입사 광선에 수직인 면에 투영되었을 때, 반지름이 단축의 길이(r_b1)와 같은 원으로 투영된다. 평면 거울(10)로의 입사 광선 중 코팅 부분(12)으로 입사한 광선은 코팅 부분(12)에서 입사 광선에 대하여 수직으로 반사되 며, 비-코팅 부분(14)으로 입사한 광선은 비-코팅 부분(14)을 투과하여 통과한다. 그러므로 도 6에서 도시되는 바와 같이 반지름이 r_b인 원형의 입사 광선이 평면 거울(10)로 입사하는 경우, 상기 입사 광선은 코팅 부분(12)에서 반사한 반지름이 r_b1인 원형의 반사 광선과 비-코팅 부분(14)을 통과한 환형의 투과 광선으로 분리된다. 입사 광선이 위치에 따라 광량이 일정한 평면파인 경우, 반사 광선과 투과 광선의 광량의 비는 수학식 1과 같다.The coating portion 12 also has a ratio of the length r _{a1 of the} major axis to the length r _b1 of the minor axis.

When the planar mirror 10 is an ellipse and is projected onto a plane perpendicular to the incident light beam, the radius is projected onto a circle equal to the length of the short axis r _b1 . Of the incident light rays entering the planar mirror 10, light rays incident on the coating portion 12 are reflected perpendicularly to the incident light rays on the coating portion 12, and light rays incident on the non-coating portion 14 are non-coated. Passes through part 14. Therefore, as shown in FIG. 6, when a circular incident light beam having a radius r _b is incident on the plane mirror 10, the incident light beam includes a circular reflection light beam having a radius r _b1 reflected by the coating part 12. It is separated into an annular transmission beam passing through the non-coated portion 14. When the incident light beam is a plane wave whose light quantity is constant according to the position, the ratio of the light amounts of the reflected light beam and the transmitted light beam is expressed by Equation 1 below.

From Equation 1, when the e value is 0.7071, the light quantity of the reflected light beam and the transmitted light beam is the same, and when it is larger than 0.7071, the light amount of the reflected light beam is larger than the light beam amount of the transmitted light beam. It becomes small.

As described above, since the incident light can be separated into two light beams and a mirror coated with a coating material that totally reflects irrespective of the wavelength, the amount of reflected light and transmitted light is determined according to the coating area.

In the above example, a beam splitting mirror is described in which the center is coated glass and the periphery is made of uncoated glass. However, it is also possible to use glass, ie mirrors, coated with a reflective material having a small aperture compared to the aperture of the incident light beam. It will be clear in this case that the mirror located at the center acts like the aforementioned coating part 12 which reflects the light rays, and the empty space at the periphery acts as the aforementioned non-coating part 14 which transmits the light rays.

In the above-described example of the beam separation method, the case where the incident light beam is circular and the reflected light beam is reflected perpendicularly to the incident light beam has been described. However, it is also possible for the incident light rays to be incident in other forms such as squares, ellipses, and the like, and it is also possible for the transmitted light or reflected rays to pass through the beam splitting mirror in other forms such as rectangles and ellipses. It is also possible that the beam splitting mirror is inclined at a predetermined angle rather than 45 ° with respect to the incident beam so that the reflected beam from the beam splitting mirror is emitted at an angle other than perpendicular to the incident beam. The shape and tilt of the mirror will be adjusted according to the intended use.

7 is an example of an optical device using the mirror described above. The optical device is composed of a light beam splitting device 10 (beam splitting mirror described above), an illumination device 20, a light collecting device 30, a specimen 40, and a detection device 50. Such optical devices are used in reflection or fluorescence microscopy, confocal microscopy and pickup systems.

The lighting device 20 includes a light source for illuminating the specimen 40. The light source may be a variety of devices, such as a light bulb that emits light of a wide wavelength, a laser that emits only light of a specific wavelength.

The light concentrating device 30 uses a convex lens or a concave mirror for focusing light rays incident in parallel or transmitting light rays incident from one point in parallel.

The test piece 40 is a device for fixing an object to be observed.

The detection device 50 is a device for detecting light in which the observation target on the specimen 40 reflects or fluoresces the light beam from the illumination device 20. The detection device 50 may be an eyepiece for direct eye observation or a device such as a CCD or a photodetector for storing an image as a data file. Alternatively, the confocal microscope may further include a pin hole.

In FIG. 7, the illumination rays emitted from the illumination device 20 go to the ray separation device 10. Of the illumination light rays incident on the light beam splitter 10, the light rays incident to the center portion are reflected, and the light rays incident on the peripheral portion are transmitted. In FIG. 7, the reflected light beam is not used and only the transmitted light beam, that is, the annular light beam from which the center is removed, proceeds to the light collecting device 30. The illumination light beams traveling to the light collecting device 30 are focused on the specimen 40 by the light collecting device 30. Thus, when the object to be observed in the specimen 40 is illuminated, it emits light having a longer wavelength than the wavelength of the light beam corresponding to the energy level of the object after reflecting or being excited by the light beam. The light reflected or fluoresced from the object to be observed on the specimen 40 then proceeds to the light collecting device 30. Reflected / fluorescent light rays propagated to the light converging device 30 become parallel waves in the light propagating device 30. Reflected / fluorescent light beams passing through the light collecting device 30 go back to the light beam splitting device 10. Of the reflection / fluorescence beams incident on the beam splitter 10, the beams incident on the periphery are transmitted through the beam splitter 10 to the lighting device 20 and are not used. Reflected by (10) and proceeds to the detection device 50 to observe the image of the observation target on the specimen (40).

In such a device, only the annular beam from which the center of the illumination beam is removed passes through the beam splitter 10 to illuminate the specimen 40, resulting in an apodization effect.

When the plane wave (lighting ray) is focused on the specimen 40 by the light collecting device 30, the image is actually a constant size rather than a point on the focal plane (the specimen 40). The brightness ( I (r) ) distribution function (point spread function (PSF)) at the focal plane is Fourier transformed by the apodization function A (r ') at the aperture (i.e., condenser 30). You can get it. When the PSF is expressed in polar coordinates, it is given by Equation 2.

In Equation 2, r is the distance from the center of the light beam on the specimen 40 surface, r ' is the distance from the center of the light beam on the light collecting device 30 surface. λ is the wavelength of the light beam, and f is the focal length of the light collecting device. J ₀ is the zero-order Bessel function.

As a comparative example, when there is no apodization effect, that is, when a constant light beam enters a circular aperture of the light converging device 30 or when all light beams incident on the light beam splitting device 10 are transmitted (0 ≤ r ' ≤ distribution of intensity (I (r)) for r _b day when a (r ') = 1 and r'> r _b day when a (r ') = 0 If) is derived by the following equation 3 from equation (2) .

In Equation 3, ν is a distance obtained by normalizing the distance ( r ) from the light ray to the wavelength and focal length in the specimen 40, J ₁ is the first order Bessel function. Equation 3 is shown by the solid line (e≡ r _b1 / r _b = 0) in FIG. In FIG. 8, the horizontal axis is a normalized distance ν, and the vertical axis is a light intensity I (ν) / I (0) normalized to 1 at (ν = 0).

In the present embodiment, when e has a value between 0 and 1, A (r ') has a distribution of 1 when r _b × e (= r _b1 ) ≤ r' ≤ r _b and 0 in other intervals. . The distribution of I (k) / I (0) was obtained by Fourier transform of Equation 2 for the case where the e value was 0.5 and 0.9, and the dashed line and the dotted line were respectively shown in FIG. 8. As shown in FIG. 8, as the value of e increases, the width of the main beam decreases, so that the resolution is improved. However, as the e value increases, the ratio of the amount of illumination light incident on the specimen 40 to the total amount of illumination light emitted from the illumination device 20 (proportional to (1-e ² )) decreases, and the side lobe It is preferable to use an appropriate value of e, since there is a disadvantage in that the relative strength of () increases (see Fig. 8).

On the other hand, unlike in Figure 7, it is also possible to illuminate the specimen 40 using the light reflected from the light beam splitter 10. In this case, the light rays emitted from the central portion of the light beam splitter 10 among the light rays emitted from the lighting device 20 pass through the light collecting device 30 to illuminate the specimen 40, and the specimen 40 reflects / fluoresces. The light beam passes through the light concentrator 30, passes through the periphery of the light beam splitter 10, and proceeds to the detection apparatus 50.

In this case, since the diameter of the light beam incident on the light converging device 30 is reduced from r _b to r _b1 , the size of the light beam formed on the focal plane in the specimen 40 increases. However, since the light reflected / fluoresced by the specimen 40 passes through only the periphery of the beam splitter 10 and proceeds to the detector, the resolution of the image obtained by the detector is improved.

In the example of the optical device described above, the case where the illumination light and the reflection / fluorescence light are circular and the reflection light in the light beam splitting device is reflected perpendicularly to the incident light beam to the light beam splitting device has been described. However, it is also possible for the incident light beam to enter the beam splitting device to enter the beam splitting device in other forms such as a rectangle and an ellipse, and also for the transmitted or reflected light to pass through the beam splitting device in other forms such as a rectangle and an ellipse. It is possible. It is also possible that the beam splitting mirror is inclined at a predetermined angle rather than 45 ° with respect to the incident beam so that the reflected beam from the beam splitting mirror is emitted at an angle other than perpendicular to the incident beam. The shape and tilt of the mirror will be adjusted according to the design parameters of the optical device using the light beam separation method according to the present invention.

Second Embodiment

9 shows a beam splitting mirror 10 'used in the second embodiment of the present invention.

The mirror 10 'is a planar mirror, and the shape and the tilt of the incident light can be adjusted according to the characteristics of the incident light and the transmitted light and the reflected light which will be described later. In this embodiment, as in the first embodiment, the case where the incident light beam is circular and the transmitted light beam and the reflected light beam are vertically separated will be described as an example. When the incident light is circular with a radius of 'a', when the plane mirror 10 'is inclined at an angle θ with respect to the incident light, the plane mirror 10' has a short axis length r _b of 'a' The length of the long axis (r _a ) must be an ellipse with 'a / cosθ'.

인 타원 모양인 평면 거울이다. 도 10에서 도시되는 바와 같이, 평면 거울(10′)은 평면 거울(10′)로의 입사 광선에 대하여 45° 기울어지게 설치된다. 그러므로 평면 거울(10)이 입사 광선에 수직인 면에 투영되었을 때, 단축의 길이(r_b)는 변하지 아니하고 장축의 길이(r_a)는

로 작아지게 되어, 타원 거울(10′)은 반지름이 단축의 길이(r_b)와 같은 원으로 투영된다. As an example an example in which the planar mirror 10 is tilted 45 ° with respect to the incident light beam is shown in FIG. 10. The mirror 10 'has a ratio of the length r _a of the major axis to the length r _b of the minor axis.

It is a flat mirror that is an elliptic shape. As shown in FIG. 10, the planar mirror 10 ′ is installed at an inclination of 45 ° with respect to the incident light beam to the planar mirror 10 ′. Therefore, when the plane mirror 10 is projected on a plane perpendicular to the incident light beam, the length of the short axis r _b does not change and the length of the long axis r _a is

The ellipsoidal mirror 10 'is projected onto a circle whose radius is equal to the length r _b of the minor axis.

The periphery of the flat mirror 10 'is a coating portion 12' which is coated with glass thin film 16 ', and the center of the flat mirror is uncoated with glass thin film 16'. Uncoated portion 14 '. The coating thin film 16 ′ may use a conventional mirror coating material capable of total reflection regardless of the wavelength of incident light as in the first embodiment.

인 타원이며, 평면 거울(10′)이 입사 광선에 수직인 면에 투영되었을 때, 반지름이 단축의 길이(r_b2)와 같은 원으로 투영된다. 평면 거울(10′)로의 입사 광선 중 코팅 부분(12′)으로 입사한 광선은 코팅 부분(12′)에서 입사 광선에 대하여 수직으로 반사되며, 비-코팅 부분(14′)으로 입사한 광선은 비-코팅 부분(14′)을 투과하여 통과한다. 그러므로 도 10에서 도시되는 바와 같이 반지름이 r_b인 원형의 입사 광선이 평면 거울(10′)로 입사하는 경우, 상기 입사 광선은 비-코팅 부분(14′)을 투과한 반지름이 r_b2인 원형의 반사 광선과 코팅 부분(12′)을 통과한 환형의 반사 광선으로 분리된다. 입사 광선이 위치에 따라 광량이 일정한 평면파인 경우, 반사 광선과 투과 광선의 광량의 비는 수학식 4와 같다.The non-coated portion 12 'also has a ratio of the length r _{a2 of the} major axis to the length r _b2 of the minor axis.

When the planar mirror 10 'is projected on a plane perpendicular to the incident ray, the radius is projected onto a circle equal to the length of the short axis r _b2 . Of the light incident to the planar mirror 10 ', the light incident on the coating portion 12' is reflected perpendicularly to the light incident on the coating portion 12 ', and the light incident on the non-coating portion 14' is reflected. It passes through the non-coated portion 14 '. Therefore, as shown in FIG. 10, when a circular incident light ray having a radius r _b is incident on the plane mirror 10 ′, the incident light ray is circular having a radius r _b2 transmitted through the non-coated portion 14 ′. It is separated into the reflected light beam of the light beam and the annular reflected light beam passing through the coating portion 12 '. When the incident light beam is a plane wave whose light quantity is constant according to the position, the ratio of the light amounts of the reflected light beam and the transmitted light beam is expressed by Equation 4.

When the e value is 0.7071 from Equation 1, the light quantity of the reflected light beam and the transmitted light beam is the same, and if it is larger than 0.7071, the light amount of the reflected light beam is smaller than the light beam beam of light. It becomes bigger.

As described above, since the incident light can be separated into two light beams and a mirror coated with a coating material that totally reflects irrespective of the wavelength, the amount of reflected light and transmitted light is determined according to the coating area.

In the above example, a light separation mirror is described in which the periphery is coated glass and the center is made of uncoated glass. However, it is also possible to use mirrors with the center removed. In this case it is clear that the mirror with the center removed acts like the aforementioned coating portion 12 'reflecting the light rays, and the empty space in the center acts like the aforementioned non-coated portion 14' transmitting the light rays. something to do.

11 is an example of an optical apparatus using the mirror described above. FIG. 11 is similar to FIG. 7 except using a light splitting device 10 'in which the central part is a coating part and the peripheral part is a non-coating part and the central part is a non-coating part and the peripheral part is a coating part instead of the light splitting device 10 Is different. In FIG. 11, the description of the same reference numerals as in FIG. 7 is omitted.

In FIG. 11, the illumination light rays emitted from the illumination device 20 proceed to the ray separation device 10 ′. Light rays incident to the periphery of the illumination light rays incident on the light beam splitter 10 'are reflected, and light rays incident on the center portion are transmitted. In FIG. 11, the reflected light beam is not used, and only the transmitted light beam, that is, the light beam having a small diameter, travels to the light collecting device 30. The illumination light beams traveling to the light collecting device 30 are focused on the specimen 40 by the light collecting device 30. Thus, when the object to be observed in the specimen 40 is illuminated, it emits light having a longer wavelength than the wavelength of the light beam corresponding to the energy level of the object after reflecting or being excited by the light beam. The light reflected or fluoresced from the object to be observed on the specimen 40 then proceeds to the light collecting device 30. Reflected / fluorescent light rays propagated to the light converging device 30 become parallel waves in the light propagating device 30. Reflected / fluorescent light beams passing through the light collecting device 30 go back to the light beam splitter 10 '. Of the reflection / fluorescence beams incident on the beam splitter 10 ', the beams incident on the center portion do not pass through the beam splitter 10' and proceed to the lighting device 20, and the beams incident on the periphery are not used. Reflected by the separation device 10 ', the detection device 50 proceeds to observe the image of the object to be observed on the specimen 40.

In this case, the light beam illuminating the specimen 40 is the same as the light beam reflected by the beam splitter 10 in the first embodiment. That is, since the diameter of the light beam incident on the light collecting device 30 is reduced from r _b to r _b2 , the size of the light beam formed on the focal plane in the specimen 40 increases. However, since the light reflected / fluoresced by the specimen 40 passes through only the periphery of the beam splitter 10 'and proceeds to the detector, the resolution of the image obtained by the detector is improved.

On the other hand, unlike in Figure 11 it is also possible to illuminate the specimen 40 using the light reflected from the light beam splitter (10 '). In this case, the light rays reflected from the periphery of the light splitter 10 ′ of the light rays emitted from the lighting device 20 pass through the light collecting device 30 to illuminate the specimen 40, and reflect / reflect from the specimen 40. The fluorescence light beam passes through the light collecting device 30 and passes through the center portion of the light beam separating device 10 'to the detection device.

In this case, the light beam illuminating the specimen 40 is the same as the light beam passing through the beam splitting apparatus 10 in the first embodiment. That is, only the annular light beam from which the center is removed passes through the light beam splitter 10 'to illuminate the specimen 40. As described above in the first embodiment, in this case, the point spread function of the phase formed on the specimen 40 by the apodization effect is as shown in FIG. 8. Therefore, the resolution of the light beam illuminating the specimen 40 can be seen to be improved.

In the above-described example of the beam splitting method and the optical device, the incident beam to the beam splitting mirror or the device is circular, and the reflected beam at the beam splitting mirror or the device is reflected perpendicularly to the incident beam to the beam splitting device. Described. However, it is also possible for the incident light beam to the beam splitting mirror or device to be incident on the beam splitting mirror or device in other forms, such as a square or an ellipse, and also the beam splitting device in the form of transmitted beams or reflected beams to another shape such as a square or an ellipse. It is also possible to pass through. It is also possible for the beam splitting mirror to be inclined at a predetermined angle rather than 45 ° with respect to the incident beam so that the reflected beam from the beam splitting mirror or device is emitted at an angle other than perpendicular to the incident beam. The shape and tilt of the mirror will be adjusted according to the design parameters of the optical device using the light beam separation method according to the present invention.

Compared to the conventional beam separation method and device, the beam separation method and the optical device use the reflection characteristics of the mirror, and thus can be used in a wide wavelength range independently of the wavelength. It can be miniaturized, there is an advantage that can improve the resolution of the optical device by the apodization effect.

The light beam separation method and optical device according to the present invention can be mainly used in a general reflection or fluorescence microscope, a confocal microscope, and a pickup system. In addition, the light beam separation method and the optical device according to the present invention may be used in a camera for dividing light rays incident on a lens into paths to the eyepiece and an image pickup unit, an interferometer using an interference effect of a plurality of light rays incident on different paths, and the like.

Various modifications and variations are possible to those skilled in the art without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (18)

Using a planar mirror composed of a reflecting unit for reflecting light and a transmitting unit for transmitting light, the light is incident on the reflecting unit among the incident light beams of the planar mirror, and is incident on the transmissive unit. 1. A beam separation method using a mirror according to claim 1, wherein one light beam is transmitted to separate one incident light beam into two light beams. The method of claim 1, wherein the reflector is a central portion of the planar mirror and the transmission part is a periphery of the planar mirror. 3. The plane mirror and the reflector are ellipses having a ratio of the length of the major axis to the length of the minor axis when the plane mirror is inclined at the predetermined angle θ with respect to the incident light beam. And the planar mirror and the reflector are projected in a circle when projected onto a plane perpendicular to the path of incident light. The method of claim 1, wherein the reflector is a periphery of the planar mirror and the transmission part is a central part of the planar mirror. The ellipse of claim 4, wherein when the plane mirror is inclined at the predetermined angle θ with respect to the incident ray, the plane mirror and the transmission portion are ellipses having a ratio of the length of the major axis to the length of the minor axis being 1 / cos. And the planar mirror and the transmission part are projected in a circle when projected onto a plane perpendicular to the path of the incident light beam. The said predetermined angle is 45 degrees, and the ratio of the length of the long axis with respect to the length of the said short axis is

Ray separation method using a mirror, characterized in that. The method of claim 1, wherein the reflecting part is glass coated with a reflective coating thin film and the transmitting part is glass which is not coated with a reflecting coating thin film. The method of claim 1, wherein the reflecting part is glass coated with a reflective coating thin film and the transmitting part is an empty space. An illumination device including a light source; And a planar mirror comprising a reflector for reflecting light rays and a transmitter for transmitting light rays, wherein the planar mirror is inclined at a predetermined angle with respect to the light beam emitted from the lighting device. Device; A light collecting device including a convex lens or a concave mirror; Specimens for fixing the object to be observed; And A detection device for detecting light rays from the observation target; The illumination beam from the illumination device is split into two beams in the beam splitter, one of the two beams separated from the illumination beam travels to the condenser and focuses on the specimen by the condenser. While illuminating the specimen, the reflected or fluorescent light beam from the specimen passes through the light concentrator and is split into two beams in the beam splitter, and one of the two beams separated from the reflected or fluorescent beam is detected. Optical device, characterized in that proceeds to the device. 10. The optical device of claim 9, wherein the reflecting portion is a central portion of the planar mirror and the transmissive portion is a periphery of the planar mirror. 11. The method of claim 10, wherein when the plane mirror is inclined at the predetermined angle θ with respect to the incident light, the plane mirror and the reflector are ellipses having a ratio of the length of the major axis to the length of the minor axis being 1 / cos. And the planar mirror and the reflecting portion are projected in a circle when projected onto a plane perpendicular to the path of incident light. 10. The optical device of claim 9, wherein the reflecting portion is a periphery of the planar mirror and the transmissive portion is a central portion of the planar mirror. The planar mirror and the transmission portion are ellipses according to claim 12, wherein when the plane mirror is inclined at the predetermined angle θ with respect to the incident light beam, the plane mirror and the transmission portion have an ratio of the length of the major axis to the length of the minor axis is 1 / cos. And the planar mirror and the reflecting portion are projected in a circle when projected onto a plane perpendicular to the path of incident light. The method of claim 11 or 13, wherein the predetermined angle is 45 degrees, and the ratio of the length of the long axis to the length of the short axis is

It is an optical device characterized by the above-mentioned. 14. The light emitting device according to any one of claims 9 to 13, wherein the illumination device is positioned in line with the light beam separation device, the light collecting device, and the specimen, and the detection device is the light beam of the reflected or fluorescent light beam from the specimen. Located in the path of the light beam reflected by the separation device, the light beam from the lighting device passes through the transmission portion of the light beam separation device and then passes through the light collecting device to the specimen, and the reflected or fluorescent light beam from the specimen And after passing through the light converging device, reflects to the reflecting unit of the light beam splitter and proceeds to the detection device. 14. The light emitting device according to any one of claims 9 to 13, wherein the detection device is positioned in line with the light beam separating device, the light collecting device, and the specimen, and the lighting device separates the light beam among the light beams from the light device. The light beam reflected from the device is directed toward the specimen, the light beam from the illumination device reflects on the reflecting portion of the beam splitting device and then passes through the light collecting device to the specimen and reflects from the specimen or And a fluorescent light beam passes through the light concentrating device and then passes through the transmission part of the light beam splitting device to proceed to the detection device. The optical device according to any one of claims 9 to 13, wherein the reflecting portion is glass coated with a reflective coating thin film and the transmitting portion is glass uncoated with a reflective coating thin film. The optical device according to any one of claims 9 to 13, wherein the reflecting portion is glass coated with a reflective coating thin film and the transmitting portion is an empty space.

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