JPH05241207A - Acoustooptical type deflector - Google Patents

Abstract

PURPOSE:To eliminate the dependence characteristic of the deflection angle on light wavelengths possessed by an acoustooptical element over the entire scanning range without impairing the aperture of an optical system for correcting a light beam by the magnification chromatic aberration corresponding to the dependence characteristic of the deflection angle on the light wavelengths by providing the above-mentioned optical system. CONSTITUTION:The respective dependence characteristics on the light wavelengths of the acoustooptical element 1, a color dispersion optical system 17 and a magnification chromatic aberration optical system 20 are specifically set and these optical systems are so disposed that the optical axis A to align the red light and green light emitted from the color dispersion optical system 17 aligns to the optical axis of the magnification chromatic aberration optical system 20. Namely, the incident light beam 3 on the acoustooptical element 1 is emitted at the deflection angle dependent on the wavelength and is made incident on the color dispersion optical system 17, by which the color dispersion is corrected. This emitted light is made incident on the magnification chromatic aberration optical system 20 and focuses and images at a point E when the deflection angle in the acoustooptical element 1 is max., at a point C when the deflection angle is min. and at a point D when the deflection angle is intermediate. Namely, the red light and green light align and image at >=2 points on an imaging plane 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acousto-optical deflector which can be used in, for example, a scanning laser microscope and deflects a light beam such as a laser beam using an acousto-optical element.

[0002]

2. Description of the Related Art In a scanning laser microscope which captures image data of a sample to be inspected by scanning the sample with a light beam, a galvanometer mirror or an acousto-optical deflector is used as an optical deflector for deflecting laser light. There is something I had.

In particular, the acousto-optic deflector deflects a light beam using an acousto-optic element, and thus has the advantages that it has no mechanically movable parts, can perform high-speed scanning, and does not generate vibration. is there. FIG. 7 shows a schematic configuration example of a conventional acousto-optic deflecting device.

In the acousto-optic deflecting device shown in the figure, a light beam 3 (for example, consisting of red light and green light) incident on the acousto-optic element 1 is driven by driving the acousto-optic element 1 with an ultrasonic oscillator 2. Can be emitted with a predetermined deflection angle.

The acousto-optic device 1 has a function of diffracting light by the compressional waves of ultrasonic waves generated inside. Therefore, by generating an ultrasonic wave having an arbitrary diffraction angle inside the acousto-optic element 1 by the ultrasonic oscillator 2, the light beam emitted from the acousto-optic element 1 can be scanned in an arbitrary direction.

However, as described above, the acousto-optic device 1
When the light beam 3 that is incident on the light beams has different wavelengths, that is, red light and green light, the deflection angle of each color light in the acoustooptic device 1 is different due to the difference in each wavelength. For example, when the wavelength of the incident light is λ, the speed of sound in the acoustooptic device 1 is Va, the wavelength of the ultrasonic wave is Λ, and the frequency of the ultrasonic wave is fo, the deflection angle θ is expressed by the following equation. sin θ = λ / Λ = λ · fo / Va

Therefore, as shown in FIG. 7, when the incident light is composed of red light and green light, the deflection angle θ _R of the emitted light 4 of red light is the deflection angle θ of the emitted light 5 of green light. It will be larger than _G.

Further, when the deflection angle of the red light and the green light is changed by changing the wavelength Λ of the ultrasonic wave about each of the emitted lights 4 and 5 (the range is set to the scanning angle ranges θ _SR and θ _SG , respectively). , And the scanning angle range of red light θ _SR
Is larger than the scanning angle range θ _SG of green light.

As a result, when the acousto-optical deflector is used in a color laser microscope using a white laser light having three colors of R, G, and B as a light source, such as a He-Cd laser, R , G, and B have different inconveniences that the image magnification is different.

Further, in a laser scanning microscope for performing fluorescence observation, since the wavelengths of the excitation light laser light and the fluorescence observation light are different, a deviation occurs in their optical paths, and a confocal optical system cannot be constructed. There is a drawback. Optical systems for eliminating these inconveniences have been proposed in JP-A-54-6564 and JP-A-61-193130.

FIG. 8 shows the configuration of the optical system proposed in Japanese Patent Laid-Open No. 54-6564. This optical system uses red light emitted from the acousto-optic device 1 with a deflection angle corresponding to each wavelength,
The green light is made incident on the prism 6 and separated into luminous fluxes of respective colors, the outgoing light of red light is received by the plane mirror 7, the outgoing light of green light is received by the plane mirror 8, and the directions of the respective reflected lights are made to coincide with each other to form the convex lens 12.
And is projected onto the same point on the screen 10.

In the figure, reference numeral 11 indicates red light when the deflection angle is maximum, reference numeral 12 indicates red light when the deflection angle is minimum, reference numeral 13 indicates green light when the deflection angle is maximum, and reference numeral 13 indicates green light when the deflection angle is minimum. The green light is indicated by reference numeral 14, respectively.

In this optical system, the magnitude relationship between the scanning angle ranges of red light and green light of the acousto-optic element 1 is θ _SR > θ _SG as in the above, but the apex angle η of the prism 6 and the refraction of the glass material are By appropriately setting the ratio and the dispersion, the scanning angles θ _SR ′ and θ _SG ′ of the respective color lights passing through the prism 6 are made equal. Further, the red light and the green light that have passed through the prism 6 are caused to have the same directions of reflected light by the plane mirror 7 and the plane mirror 8 having an appropriate angle difference, and then are passed through the convex lens 9 so that each color light is reflected on the screen 14. Since the light is condensed, the red light and the green light can be matched over the entire scanning range. In the figure, the case where both the red light and the green light are irradiated to the point K on the screen 14 when the deflection angle is the maximum and to the point J when the deflection angle is the minimum is shown.

FIG. 9 shows the structure of the optical system proposed in Japanese Patent Laid-Open No. 61-193130. This optical system corrects the wavelength-dependent characteristic of the deflection angle by making the outgoing light of the acousto-optical element 1 incident on a color dispersion optical system 17 including a convex lens 15 and a prism 16.

In this optical system, the prism 16 is arranged so as to have a conjugate relationship with the acousto-optic element 1 via the convex lens 15, and the red light 18 and the green light 19 emitted from the acousto-optic element 1 are prism 16 by the convex lens 15. It is focused on. Then, by appropriately setting the apex angle, the refractive index, and the dispersion of the prism 16, the red light and the green light that have passed through the prism 16 are matched on the optical axis A.

[0016]

However, in the optical system shown in FIG. 8, red light and green light are passed through different areas of the pupil of the convex lens 9 respectively, so that such an optical system is laser-scanned. When used as an optical deflecting device for a microscope, there is a problem in that the numerical aperture of the objective lens is reduced and the resolution is reduced.

In the optical system shown in FIG. 9, the prism 16 can match the red light and the green light only on the optical axis A, and in the other range, the red light and the green light emitted from the prism 16 can be combined. The emitting directions do not match. Therefore, the range in which the wavelength-dependent characteristic of the deflection angle can be corrected is limited to the extremely narrow scanning angle range.

The reason why the emitting directions of the red light and the green light do not coincide will be described with reference to FIG. Note that reference numeral 18
Reference numeral 19-1 indicates red light at the maximum deflection angle, 18-2 indicates red light at the minimum deflection angle, reference numeral 19-1 indicates green light at the maximum deflection angle, and 19-2 indicates green light at the minimum deflection angle. Shows.

Since the scanning angle range of each of red light and green light by the acousto-optic device 1 is θ _SR > θ _SG as described above, the light beam 3 is scanned within a predetermined range as shown in FIG. If the red light 18 and the green light 19 are coincident with each other, the red light 18
Therefore, a deviation occurs in the emission direction of the green light 19. The shift angle α is approximately (θ _SR ′ −θ _SG ′) / 2 at both ends of the scanning angle range.

For example, TeO ₂ is used for the acoustooptic device,
The speed of sound Va in the acousto-optic device is 650 m / s, the wavelength of the red laser light is 633 nm, and the wavelength of the green laser light is 48.
8 nm, change range of ultrasonic frequency fa is 100 ± 25
In MHz, the deflection angle θ _R of red laser light is 5.5886
The scanning angle θ _SR is 2.8035 °. The deflection angle θ _G of the green laser light is 4.3056 °, and the scanning angle θ _SG is 2.1570 °.

Although the difference between the deflection angles θ _R and θ _G can be corrected by the optical system shown in FIG. 9, the difference between the scanning angles θ _SR and θ _SG cannot be completely corrected as described above. If the lateral magnification of the convex lens 15 is 1, the shift angle α is about 0.3 °. This deviation angle α is the scanning angle θ _SR , θ
_This corresponds to 11 to 14% of _SG , indicating that the wavelength-dependent characteristic of the deflection angle is not sufficiently corrected.

The present invention has been made in view of the above circumstances, and an acousto-optical deflector capable of eliminating the wavelength-dependent characteristic of the deflection angle over the entire scanning range without damaging the aperture of the optical system. The purpose is to provide.

[0023]

According to a first aspect of the present invention, there is provided an acousto-optical deflector according to the present invention, wherein the acousto-optical deflector deflects a light beam containing a plurality of wavelengths by an acousto-optical element. Is provided with a lateral chromatic aberration optical system that corrects the light beam by lateral chromatic aberration corresponding to the light wavelength dependence characteristic of the deflection angle.

According to a second aspect of the present invention, the acousto-optic deflector according to the present invention corrects the chromatic dispersion of the light beam by giving the light beam a chromatic dispersion corresponding to the chromatic dispersion of the light beam generated by the acousto-optic element. A chromatic dispersion optical system and a lateral chromatic aberration optical system that corrects the light beam by lateral chromatic aberration corresponding to the light wavelength dependence characteristic of the deflection angle of the acousto-optic element are provided.

According to a third aspect of the present invention, there is provided an acousto-optic deflector according to the present invention, which comprises an entrance-side prism arranged on the entrance side of the acousto-optic element and an exit-side prism arranged on the exit side of the acousto-optic element. A chromatic aberration chromatic aberration optical system that corrects the light beam by chromatic aberration of magnification corresponding to the light wavelength dependence characteristic of the deflection angle of the acousto-optic element.

[0026]

According to the acousto-optic deflecting device of the present invention corresponding to claim 1, the light beam is deflected by the acousto-optic element, and the light wavelength dependence characteristic of the deflection angle is corrected by the chromatic aberration of magnification of the chromatic aberration of magnification optical system. It For this reason, the light wavelength-dependent characteristic light of the deflection angle can be eliminated over the entire scanning range without having to separate the emitted light of the acousto-optical element by color and then form the image at the same point with the convex lens.

According to the acousto-optic type deflecting device of the present invention corresponding to the second aspect, since the chromatic dispersion that the acousto-optical element receives is eliminated by the chromatic dispersion optical system, the difference between the deflection angles of the respective wavelengths. Is corrected. Then, the difference in the scanning angle range of each wavelength that cannot be completely corrected by the chromatic dispersion optical system is corrected by the lateral chromatic aberration of the lateral chromatic aberration optical system.

According to the acousto-optic type deflecting device of the present invention corresponding to claim 3, the incident light is separated into respective wavelengths by the incident side prism, is incident on the acousto-optical element, and is emitted from the acousto-optical element. Light is overlapped by the exit side prism and coincides. Then, the optical wavelength dependence characteristic of the deflection angle of the light beam passing through the lateral chromatic aberration optical system is corrected by the lateral chromatic aberration of the lateral chromatic aberration optical system.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of the optical system of the acousto-optic deflecting device according to the first embodiment of the present invention. In addition,
The parts having the same functions as those of the optical deflector shown in FIG. 9 are designated by the same reference numerals.

The acousto-optic deflecting device of this embodiment is arranged on the acousto-optic element 1, an ultrasonic oscillator (not shown) for driving the acousto-optic element 1, and an optical path on the exit side of the acousto-optic element 1 as described above. It has a chromatic dispersion optical system 17 composed of a convex lens 15 and a prism 16, and a chromatic aberration of magnification corresponding to the deviation of the scanning angle range of each wavelength generated when the light beam is scanned and is arranged in the optical path on the emission side of the chromatic dispersion optical system 17. A chromatic aberration of magnification optical system 20 is provided.

The magnification chromatic aberration optical system 20 is constructed by combining a convex lens 21 made of low dispersion glass such as crown glass and a concave lens 22 made of high dispersion glass such as flint glass. Here, the axial chromatic aberration and the lateral chromatic aberration of the lateral chromatic aberration optical system 20 will be described with reference to FIGS. 2 and 3.

FIG. 2 shows a state in which incident light 24 consisting of red light and green light is incident on the lateral chromatic aberration optical system 20 in parallel with the optical axis. As shown in the figure, when the incident light 24 is incident on the convex lens 21, chromatic aberration occurs and color separation is performed into red light 25 and green light 26. When the red light 25 and green light 26 are incident on the concave lens 22, axial chromatic aberration is generated. It is corrected and focused on one point B. Such axial chromatic aberration correction can be realized by appropriately setting the Abbe numbers and powers of the convex lens 21 and the concave lens 22 and the distance d between the two.

By the way, based on the position information of the point B where the red light 25 and the green light 26 emitted from the concave lens 22 are condensed, the rear main surface H _R ′ for the red light and the rear main surface for the green light. H _G ′ can be obtained. Further, the focal length f _R for red light and the focal length f _G for green light can be obtained from the positions of the two rear main surfaces H _R ′, H _G ′. An optical system that achieves axial chromatic aberration correction by the above method generally has a relationship of f _R <f _G.

FIG. 3 shows a state in which off-axis rays 27 and 28 are incident on the chromatic aberration of magnification optical system 20. As shown in the figure, the red chromatic light 29 and the green light 30 are emitted from the lateral chromatic aberration optical system 20 in correspondence with the off-axis light rays 27, and the red light emission 31 and the green light are emitted in correspondence with the off-axis light rays 28. The emitted light 32 is emitted. And the red emitted light 29, 31
And the green emission light 30 and 32 are different image heights Y _R ,
An image is formed with Y _G , and a difference occurs in the image forming position. These image heights Y
_R and Y _G are proportional to the focal lengths f _R and f _G , respectively.

Here, the difference between the image forming positions of the red light and the green light is compared with the difference between the scanning angle ranges of the red light and the green light of the color dispersion optical system 17 shown in FIG. Then,
It can be seen that the light wavelength dependence characteristics of both are opposite to each other. That is, when the direction (A axis) in which red light and green light are completely coincident and emitted in FIG. 10 is regarded as the optical axis, the respective scanning angle ranges of red light and green light are ±.
Since θ _SR ′ / 2 and ± θ _SG ′ / 2 (θ _SR ′> θ _SG ′), by combining the chromatic dispersion optical system 17 and the magnification chromatic aberration optical system 20 as in this embodiment, the wavelength It is possible to correct the deviation of the scanning angle range due to the difference.

Therefore, in this embodiment, the light wavelength dependence characteristics of the acousto-optic element 1, the chromatic dispersion optical system 17, and the chromatic aberration of magnification optical system 20 are set so as to satisfy the relationship of f _R θ _SR ′ = f _G θ _SG ′. The optical axis A, which is set and the red light and the green light emitted from the color dispersion optical system 17 coincide with each other, is arranged so as to coincide with the optical axis of the lateral chromatic aberration optical system 20.

In the present embodiment configured as described above, the light beams incident on the acousto-optical element 1 are emitted at the deflection angles depending on the wavelengths, and the emitted light is incident on the chromatic dispersion optical system 17 to cause chromatic dispersion. Will be corrected.

The prism 16 of the color dispersion optical system 17
The emitted light emitted from the red light 18-1 'and the green light 19- is emitted when the deflection angle in the acoustooptic device 1 is maximum.
It is separated into 1'and enters the chromatic aberration of magnification optical system 20. The red light 18-1 'and the green light 19-1' which have entered the chromatic aberration of magnification optical system 20 are corrected by the chromatic aberration of magnification of the chromatic aberration of chromatic aberration system 20 and pass through the paths 18-1 '' and 19-1 ''. An image is formed at each point E.

When the deflection angle in the acousto-optic element 1 is the minimum, the red light 18 emitted from the color separation optical system 17 is emitted.
-2 'and green light 19-2' are separated and enter the lateral chromatic aberration optical system 20. Then, the chromatic aberration of magnification of the optical system 20 is corrected by the chromatic aberration of magnification and the paths 18-2 ″ and 19-
An image is formed at each point C through 2 ″.

When the deflection angle in the acousto-optic element 1 corresponds to the middle of the scanning angle range, both the red light and the green light are emitted along the A axis, so that they are condensed and imaged at the point D. Further, the scanning angle range θ _SR ′ of red light and the scanning angle range θ _SG ′ of green light can be regarded as linear functions of the frequency fa of the ultrasonic wave, respectively, and the focal lengths f _R of red light and green light f _R , f _G is a constant peculiar to the lateral chromatic aberration optical system 20. Therefore, if the red light and the green light are focused on two or more points on the image plane 23, the image plane 2
It can be said that the light wavelength dependence characteristic can be eliminated over the entire scanning range from point C to point E on FIG.

As described above, according to the present embodiment, since the chromatic aberration of magnification optical system 20 having the chromatic aberration of magnification that cancels the light wavelength dependent characteristics of the acousto-optic element 1 and the color separation optical system 17 is provided,
The light wavelength dependence can be eliminated over the entire scanning range without damaging the aperture of the optical system, and the accuracy required for the color laser microscope or the fluorescence laser scanning microscope can be sufficiently achieved.

Next, an acousto-optical deflecting device according to a second embodiment of the present invention will be described with reference to FIG. In addition,
Portions having the same functions as those of the apparatus shown in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

In the acousto-optic deflecting device of this embodiment, the entrance side prism 33 is arranged on the entrance side of the acousto-optic element 1, the exit side prism 34 is arranged on the exit side of the acousto-optic element 1, and the exit side prism is further arranged. The magnification chromatic aberration optical system 20 having the above-described configuration is arranged on the exit side of 34.

The incident-side prism 33 separates the incident light 40 into red light 41 and green light 42 and makes them incident on the acoustooptic device 1 at arbitrary incident angles θ _iR and θ _iG . The incident angles θ _iR and θ _iG are set to angles such that the diffraction efficiency of the red light 41 and the green light 42 in the acoustooptic device 1 is maximized.

Further, the exit side prism 34 is set so that the corresponding outgoing red light 43 and outgoing green light 44 coincide with each other when the diffraction efficiencies of the respective incident colored lights 41, 42 are maximum. Then, the lateral chromatic aberration optical system 2 is placed on the central axis F of the scanning range of the outgoing light emitted from the outgoing side prism 34.
The optical axes of 0 are matched.

In this embodiment constructed as described above, the incident light 40 is split into the red light 41 and the green light 42 by the incident-side prism 33, whereby the incident angles θ _iR and θ at which the diffraction efficiency is maximized. _It is made incident on the acousto-optic device 1 with _iG .
The red light 43 and the green light 44, which have been deflected by the acousto-optic device 1 driven by an ultrasonic oscillator (not shown), are overlapped by the emission side prism 34 and coincide with each other.

The scanning angle ranges θ _SR and θ _SG of the red light 43 and the green light 44 have a relationship of θ _SR > θ _SG , but the deviation of the scanning angle range is corrected by the chromatic aberration of magnification of the chromatic aberration of magnification optical system 20. Then, an image is formed at the same point on the image plane 23.

As described above, according to this embodiment, the red light 43 and the green light 44 matched by the exit side prism 34 are further corrected by the chromatic aberration of magnification of the chromatic aberration of magnification optical system 20, so that the optical system. It is possible to eliminate the light wavelength dependency characteristic over the entire scanning range without damaging the aperture of the above, and it is possible to obtain the same effect as that of the first embodiment.

Moreover, since the incident side prism 33 is provided, the incident angles θ _iR and θ _iG of the red light 41 and the green light 42 on the acousto-optical element 1 can be set arbitrarily, so that the diffraction by the acousto-optical element 1 is performed. Efficiency can be maximized.

Further, since the entrance side prism 33 and the exit side prism 34 act as a color dispersion optical system, there is no requirement for the acousto-optic device 1 and the prism 16 to have a conjugate relationship as in the first embodiment. The entire device can be miniaturized. Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the acousto-optic device 1 is used.
And an ultrasonic generator (not shown) for driving the same, and a lateral chromatic aberration optical system 20 configured in the same manner as described above.

In this embodiment, the optical axis of the incident laser light 50 consisting of red light and green light is made coincident with the optical axis of the chromatic aberration of magnification optical system 20. The condition for eliminating the light wavelength dependence characteristic at this time is f _R · λ _R = f _G · λ _G. Note that λ _R
Indicates the wavelength of red light, and λ _G indicates the wavelength of green light.

By satisfying the above conditions, when the deflection angle in the acousto-optic element 1 is the maximum, the incident laser beam 5
Reference numeral 0 denotes an acousto-optical element 1 which is separated into red light 51 and green light 53 and is incident on a lateral chromatic aberration optical system 20, is corrected by lateral chromatic aberration of the lateral chromatic aberration optical system 20, and is imaged at a point J on an imaging surface 23. ..

When the deflection angle in the acousto-optic element 1 is the minimum, the red light 52 and the green light 54 are separated and enter the chromatic aberration of magnification optical system 20, and are corrected by the chromatic aberration of magnification, and are corrected to the K point of the image plane 23. Image each. According to the present embodiment as described above, it is possible to obtain the same effects as those of the above-mentioned respective embodiments, and further there is an advantage that the configuration of the optical system can be simplified. Next, as a fourth embodiment, an example in which the deflection device of the optical system shown in FIG. 4 is applied to a fluorescence confocal laser scanning microscope will be described. FIG. 6 shows the overall configuration of this embodiment.

In this embodiment, the laser light emitted from the Ar ion laser tube 60 is incident on the beam expander 61 and converted into a predetermined beam diameter, and the converted laser light is converted into the light beam 40 by the dichroic mirror 62. Incident,
Here, the light is reflected and enters the incident side prism 33 of the acousto-optic deflector as excitation light. The structure of the acousto-optic deflector is the same as that of the second embodiment.

Then, the light beam that has passed through the acousto-optic deflector is incident on the first relay lens 63, and then is incident on the second relay lens 65 via the galvanometer mirror 64. Further, the light passes through the pupil 67 of the objective lens 66 and irradiates the fluorescence-stained fluorescent sample 68. Here, the acousto-optic element 1, the galvanometer mirror 64, and the objective lens pupil 67 have a conjugate positional relationship.

On the other hand, the fluorescence observation light generated from the fluorescence sample 68 passes through the galvano mirror 64 and the acousto-optic type deflecting device again and is incident on the dichroic mirror 62. Then, the fluorescence observation light transmitted through the dichroic mirror 62 is
An image is formed on the confocal pinhole 72 by the imaging lens 71, and light passing through the confocal pinhole 72 is detected by the photomultiplier 73.

In the present embodiment configured as described above, the excitation light shown by the broken line in the figure, whose optical wavelength-dependent characteristic is corrected by the lateral chromatic aberration optical system 20, is scanned by the acoustooptic device 1 in the X direction, and the galvanometer mirror is obtained. Scanning is performed in the Y direction by the rotation of 64, and as a result, the fluorescent sample 68 is XY scanned by the excitation light.

When the fluorescent sample 68 is XY scanned with excitation light,
The fluorescence observation light passes through the path shown by the solid line in the figure to form an image on the image forming surface 23, and the light wavelength dependence characteristic is corrected by the acousto-optic deflecting device and enters the dichroic mirror 62. Then, the light passes through the dichroic mirror 62, enters the imaging lens 71, and is imaged on the confocal pinhole 72. further,
Stray light is removed by the confocal pinhole 72 and detected by the photomultiplier 73. A fluorescent confocal image can be obtained by an image display device (not shown) based on the detection signal of the photomultiplier 73.

For example, FITC is used as the fluorescent reagent of the fluorescent sample 68.
(Fluorescein-s-isothiocyanate) and the excitation light wavelength is 488 nm, the exposure wavelength of FITC is about 52
Since it is 0 nm, the acousto-optic deflector has a wavelength of 488 nm.
And 520 nm will correct the light wavelength dependence characteristic.

[0061]

As described above in detail, according to the present invention, there is provided an acousto-optical deflector capable of eliminating the wavelength-dependent characteristic of the deflection angle over the entire scanning range without damaging the aperture of the optical system. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an acousto-optical deflector according to a first embodiment of the present invention.

FIG. 2 is a diagram showing axial chromatic aberration correction by a lateral chromatic aberration optical system provided in the acousto-optic deflecting device of the first embodiment.

FIG. 3 is a diagram showing lateral chromatic aberration of a lateral chromatic aberration optical system provided in the acousto-optic deflecting device of the first embodiment.

FIG. 4 is a configuration diagram of an acousto-optical deflector according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of an acousto-optical deflector according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a fluorescence confocal laser scanning microscope according to a fourth embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional acousto-optic deflecting device.

FIG. 8 is a diagram showing a conventional example of an acousto-optic deflecting device that matches the scanning ranges.

FIG. 9 is a diagram showing a conventional example of an acousto-optical deflector having a color dispersion optical system.

FIG. 10 is a diagram for explaining a problem of an acousto-optic type deflection device including a color dispersion optical system.

[Explanation of symbols]

1 ... Acousto-optic element, 15 ... Convex lens, 16 ... Prism,
17 ... Chromatic dispersion optical system, 20 ... Magnification chromatic aberration optical system, 21 ...
Convex lens, 22 ... Concave lens, 23 ... Image plane.

Claims (3)

[Claims] 1. An acousto-optic deflecting device for deflecting a light beam containing a plurality of wavelengths by means of an acousto-optic element, wherein the light beam is corrected by chromatic aberration of magnification corresponding to a light wavelength dependence characteristic of a deflection angle of the acousto-optic element. An acousto-optic deflecting device having a lateral chromatic aberration optical system. 2. An acousto-optic deflecting device for deflecting a light beam containing a plurality of wavelengths by means of an acousto-optic element, wherein chromatic dispersion corresponding to chromatic dispersion of the light beam produced by the acousto-optic element is applied to the light beam. A chromatic dispersion optical system that corrects the chromatic dispersion of the light beam, and a chromatic aberration chromatic aberration optical system that corrects the light beam by chromatic aberration of magnification corresponding to the light wavelength dependence property of the deflection angle of the acousto-optic device. Acousto-optic deflector. 3. An acousto-optic deflecting device for deflecting a light beam containing a plurality of wavelengths by means of an acousto-optic element, wherein an entrance-side prism disposed on the entrance side of the acousto-optic element and an exit side of the acousto-optic element. An acousto-optic deflection comprising: an exit-side prism that is arranged; and a lateral chromatic aberration optical system that corrects the light beam by lateral chromatic aberration corresponding to a light wavelength dependence characteristic of a deflection angle of the acousto-optic element. apparatus.