JP2007328113A - Laser modulator and microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser modulator capable of modulating laser beams having a plurality of wavelengths at high speed and to provide a microscope. <P>SOLUTION: The laser modulator has a laser light source 10 radiating the laser beams having the plurality of wavelengths, a multi-wavelength modulating means 11 respectively independently modulating the laser beams having the plurality of wavelengths and a high speed modulating means 12 modulating outputted beams from the multi-wavelength modulating means 11 at a speed higher than that of the multi-wavelength modulating means 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser modulation device and a microscope.

Conventionally, a laser modulation device using an acousto-optic element such as an AOM (Acousto-Optic Modulator) or an AOTF (Acousto-Optic Tunable Filter) is known (see, for example, Patent Document 1).
JP-A-2005-25054

  However, while the AOM that is an acoustooptic device can modulate laser light at high speed, it can only modulate laser light having a single wavelength. For this reason, when inputting laser light of a plurality of wavelengths to the AOM, an optical filter having spectral characteristics, such as an interference film, is arranged on the input side of the AOM, and the wavelength of the laser light input to the AOM is selected. I had to.

  Further, the output angle of the output light (first-order diffracted light) varies depending on the wavelength of the input laser light. For this reason, in a situation where it is desired to fix the emission angle of the output light, an AOM is prepared for each wavelength, and the laser light of each wavelength must be individually modulated.

  Further, AOTF, which is another acoustooptic device, can simultaneously modulate laser beams having a plurality of wavelengths, unlike the above-described AOM. The AOTF can also maintain the output angle of the output light (first-order diffracted light) substantially constant without depending on the wavelength of the laser light.

  However, such an AOTF cannot be used in a situation where high-speed modulation is desired because the modulation speed is slower than that of the AOM.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a laser modulation device and a microscope capable of modulating laser beams having a plurality of wavelengths at high speed.

In order to solve the above problems, the present invention
A laser light source for irradiating laser beams of a plurality of wavelengths;
Multi-wavelength modulation means for independently modulating the laser beams of the plurality of wavelengths;
High-speed modulation means for modulating the output light from the multi-wavelength modulation means faster than the multi-wavelength modulation means;
A laser modulation device is provided.

  Moreover, the microscope provided with the laser modulation apparatus of this invention is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the laser modulation apparatus and microscope which can modulate the laser beam of a some wavelength at high speed can be provided.

Hereinafter, a laser modulation device and a microscope according to each embodiment of the present invention will be described in detail with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a diagram showing a configuration of a laser scanning microscope including a laser modulation device according to the first embodiment of the present invention.

  As shown in FIG. 1, the laser scanning microscope 1 is a laser scanning microscope, which includes a microscope main body 2, a laser modulation device 3 that supplies laser light having a plurality of wavelengths to the microscope main body 2 as illumination light, The computer 5 includes an observation monitor 4. The microscope main body 2 and the laser modulation device 3 are connected via an optical fiber 6.

FIG. 2 is a diagram showing a configuration of the laser modulation device 3 according to the first embodiment of the present invention.
As shown in FIG. 2, the laser modulator 3 includes a multi-laser light source 10 that emits a plurality of laser beams having different wavelengths, an AOTF 11 that can simultaneously modulate a plurality of laser beams, and a single-wavelength laser beam. And AOM 12 capable of high-speed modulation.

  In the laser modulation device 3, the AOTF 11 is disposed on the output light path of the multi-laser light source 10, and the AOM 12 is disposed on the output light path of the first-order diffracted light out of the output light from the AOTF 11. Further, a coupler 6 a of the optical fiber 6 is disposed on the output optical path of the 0th-order diffracted light out of the output light from the AOM 12. The coupler 6a incorporates a lens (not shown) for efficiently introducing laser light into the optical fiber 6.

  In this laser modulation device 3, the laser beams having a plurality of wavelengths emitted from the multi-laser light source 10 are independently modulated by the AOTF 11, and the first-order diffracted light is input to the AOM 12. This light is modulated at high speed by the AOM 12, and the zero-order diffracted light is input to the coupler 6a. The light input to the coupler 6a is introduced into the microscope body 2 as illumination light through the optical fiber 6.

  With the above configuration, the laser modulation device 3 specifically selects ON / OFF and dimming, that is, the wavelength of a plurality of wavelengths of laser light independently at a modulation speed of about 10 μs by the AOTF 11, and selects the wavelength of that wavelength. The intensity of the laser light is adjusted, and the output light from the AOTF 11 can be turned ON / OFF (switched) by the AOM 12 at a modulation speed of about 1 μs.

  In this manner, the laser modulation device 3 can modulate laser light having a plurality of wavelengths at high speed. In the laser modulation device 3, the 0th-order diffracted light of the output light from the AOM 12 is input to the coupler 6 a as the output light of the laser modulation device 3. Therefore, the emission angle of the output light does not depend on the wavelength. Can always be kept constant.

  In the laser scanning microscope 1 having the above configuration, the laser light from the laser modulation device 3 is introduced into the microscope main body 2 through the optical fiber 6, converted into linearly polarized light by the polarizing plate 15, and then polarized light. Reflected by the splitter 16. This light passes through the quarter-wave plate 17 and the deflecting mirror 18 in this order, and is then irradiated onto the surface of the sample 23 on the stage 22 through the lenses 19, 20, and 21. Here, the deflection mirror 18 is driven by two galvanometers (not shown), whereby the irradiation light can be scanned on the surface of the sample 23.

  Then, the light reflected by the surface of the sample 23 enters the polarization beam splitter 16 again through the lenses 21, 20, 19, the deflection mirror 18, and the quarter wavelength plate 17 in order. This light passes through the polarization beam splitter 16 and is guided to the photoelectric detector 25 through the lens 24, and an image of the irradiation point of the sample 23 is formed on the photoelectric surface of the photoelectric detector 25. Accordingly, the computer 5 can create image data of the sample 23 from the output of the photoelectric detector 25 at each scanning point and display it on the observation monitor 4.

From the above, it is possible to realize the laser scanning microscope 1 that can modulate laser light having a plurality of wavelengths at high speed.
In the present embodiment, the multi-laser light source 10 is used as the laser light source. However, the present invention is not limited to this, and a fiber laser that uses a wavelength-variable laser light source or performs laser oscillation using an optical fiber. A light source may be used, or a plurality of laser light sources having different wavelengths may be provided.

  In the present embodiment, the laser scanning microscope 1 can be used as a confocal microscope if a pinhole is disposed immediately before the photoelectric detector 25 and at a position conjugate with the sample 23. Further, in such a confocal microscope, the polarizing plate 15 and the quarter wavelength plate 17 are removed, and a dichroic mirror is used in place of the polarizing beam splitter 16, and a fluorescent filter is provided in the optical path between the dichroic mirror and the photoelectric detector 25. Can be used as a fluorescent confocal microscope. Here, the dichroic mirror reflects the laser beam from the laser modulation device 3 and transmits the fluorescence emitted from the sample 23 by exciting the sample 23 with this laser beam. The fluorescent filter does not transmit the laser light reflected by the specimen 23 and transmits the fluorescence. Furthermore, in the case of observing a specimen by photobleaching with such a fluorescent confocal microscope, it is necessary to dim the laser beam independently for each wavelength, but the location of the dimming pixel is known in advance. Therefore, by controlling the timing of modulation by AOTF, it is possible to freely control the location where light fading occurs.

In each embodiment shown below, a modification of laser modulation device 3 concerning this embodiment is shown.
(Second Embodiment)
FIG. 3A is a diagram showing a configuration of a laser modulation apparatus according to the second embodiment of the present invention.
As shown in FIG. 3A, the laser modulation device 30 includes a multi-laser light source 31, an AOTF 32, an AOM 33, and a prism having a triangular prism shape for eliminating the wavelength dependence of the output angle of the output light of the AOM 33. 34.

  In the laser modulation device 30, the AOTF 32 is arranged on the emission optical path of the multi-laser light source 31, and the AOM 33 is arranged on the emission optical path of the first-order diffracted light out of the output light from the AOTF 32. The prism 34 is disposed in the vicinity of the AOM 33 on the outgoing optical path of the first-order diffracted light out of the output light from the AOM 33. Further, a coupler 6 a of the optical fiber 6 is disposed on the outgoing optical path of the prism 34.

  In this laser modulation device 30, the laser beams having a plurality of wavelengths emitted from the multi-laser light source 31 are independently modulated by the AOTF 32, and the first-order diffracted light is input to the AOM 33. This light is modulated at high speed by the AOM 33, and the first-order diffracted light is input to the prism 34. This light is refracted by the prism 34 and input to the coupler 6a. The light input to the coupler 6a is introduced as illumination light into the microscope body via the optical fiber 6.

  With this configuration, the laser modulation device 30 can achieve the same effects as the laser modulation device 3 according to the first embodiment. Further, in the laser modulator 30, as described above, the first-order diffracted light whose traveling direction varies depending on the wavelength among the output light of the AOM 33 is refracted by the prism 34, and the coupler 6 a is output as the output light of the laser modulator 30. The output angle of the output light can always be kept constant regardless of the wavelength. Further, as described above, since the laser modulation device 30 is configured to use the first-order diffracted light of the output light of the AOM 33, it is possible to ensure a large dimming range as compared with the first embodiment. . The light control range refers to the range of the smallest value and the largest value of the light intensity when the laser light is modulated.

  In the laser modulation device 30 according to the present embodiment, instead of the prism 34 described above, other optical elements that can eliminate the wavelength dependency of the output angle (first-order diffracted light) of the output light (first-order diffracted light) of the AOM 33, such as a diffraction grating, etc. Can also be used.

(Third embodiment)
FIG. 3B is a diagram showing a configuration of a laser modulation device according to the third embodiment of the present invention.
As shown in FIG. 3B, the laser modulation device 40 includes a multi-laser light source 41, an AOTF 42, a first AOM 43, and a second AOM 44.

  In the laser modulation device 40, the AOTF 42 is arranged on the emission optical path of the multi-laser light source 41, and the first AOM 43 is arranged on the emission optical path of the first-order diffracted light out of the output light from the AOTF 42. In addition, the second AOM 44 is on the emission optical path of the first-order diffracted light out of the output light from the first AOM 43 and has the opposite direction to the first AOM 43, that is, the wavelength dependence of the output angle of the output light (first-order diffracted light) of the first AOM 43. It is arranged in a direction to cancel (offset) the property. Further, a coupler 6 a of the optical fiber 6 is disposed on the outgoing optical path of the second AOM 43.

  In this laser modulation device 40, the laser beams of a plurality of wavelengths emitted from the multi-laser light source 41 are independently modulated by the AOTF 42, and the first-order diffracted light is input to the first AOM 43. This light is modulated at high speed by the first AOM 43, and the first-order diffracted light is input to the second AOM 44. This light is similarly modulated at high speed by the second AOM 44, and the first-order diffracted light is input to the coupler 6a. The light input to the coupler 6a is introduced as illumination light into the microscope body via the optical fiber 6.

  With this configuration, the laser modulation device 40 can achieve the same effects as the laser modulation device 3 according to the first embodiment. Further, in the present laser modulation device 40, the deviation of the emission angle of the first-order diffracted light of the first AOM 43 that occurs depending on the wavelength is eliminated (offset) by the second AOM 44, and input to the coupler 6a as the output light of the present laser modulation device 40. Therefore, the emission angle of the output light can always be kept constant without depending on the wavelength. Further, as described above, since the laser modulation device 40 is configured to use the first-order diffracted light of the output light of the second AOM 44, the dimming range in the first embodiment is the same as in the second embodiment. In comparison, it can be ensured.

(Fourth embodiment)
FIG.3 (c) is a figure which shows the structure of the laser modulation apparatus based on 4th Embodiment of this invention.
As shown in FIG. 3C, the laser modulation device 50 includes a multi-laser light source 51, a first AOTF 52, a second AOTF 53, and an AOM 54.

  In the laser modulation device 50, the first AOTF 52 is arranged on the emission optical path of the multi-laser light source 51, and the second AOTF 53 is arranged on the emission optical path of the first-order diffracted light out of the output light of the first AOTF 52. Further, the AOM 54 is disposed on the outgoing optical path of the first-order diffracted light out of the output light of the second AOTF 53. Further, a coupler 6 a of the optical fiber 6 is disposed on the output optical path of the 0th-order diffracted light in the output light from the AOM 54.

  In such a laser modulation device 50, laser beams of a plurality of wavelengths emitted from the multi-laser light source 51 are independently modulated by the first AOTF 52, and the first-order diffracted light is input to the second AOTF 53. This light is further modulated by the second AOTF 53, and the first-order diffracted light is input to the AOM 54. This light is modulated at high speed by the AOM 54, and the zero-order diffracted light is input to the coupler 6a. The light input to the coupler 6a is introduced as illumination light into the microscope body via the optical fiber 6.

  With this configuration, the laser modulation device 50 can achieve the same effects as the laser modulation device 3 according to the first embodiment. In the laser modulation device 50, the 0th-order diffracted light of the output light from the AOM 54 is input to the coupler 6a as the output light of the laser modulation device 50. Therefore, the emission angle of the output light does not depend on the wavelength. Can always be kept constant.

Further, in the laser modulation device 50, by using the two AOTFs 52 and 53 arranged in series, it is possible to ensure a very large dimming range as compared with the first embodiment. For this reason, it is more effective when the laser modulation device 50 is used in a fluorescent confocal microscope. The two AOTFs 52 and 53 can be driven by a common driving device, so that the cost can be reduced.
If the AOM 54 in the laser modulation device 50 is removed and the output of the second AOTF 53 is directly input to the coupler 6a, a laser modulation device that can ensure only a large light control range can be configured.

  Even if the laser modulation device according to the second, third, or fourth embodiment described above is used in place of the laser modulation device 3 in the first embodiment, a plurality of wavelengths are obtained as in the first embodiment. A laser scanning microscope capable of modulating the laser beam at a high speed can be realized.

It is a figure which shows the structure of the laser scanning microscope provided with the laser modulation apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the laser modulation apparatus which concerns on 1st Embodiment of this invention. (A), (b), (c) is a figure which shows the structure of the laser modulation apparatus based on 2nd, 3rd, 4th embodiment of this invention, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser scanning microscope 2 Microscope main body 3 Laser modulator 5 Computer 6 Optical fiber 10 Multi-laser light source 11 AOTF
12 AOM

Claims (7)

A laser light source for irradiating laser beams of a plurality of wavelengths;
Multi-wavelength modulation means for independently modulating the laser beams of the plurality of wavelengths;
High-speed modulation means for modulating the output light from the multi-wavelength modulation means faster than the multi-wavelength modulation means;
A laser modulation device comprising:   The laser modulation apparatus according to claim 1, wherein each of the multi-wavelength modulation unit and the high-speed modulation unit includes an acousto-optic element.   3. The laser modulation device according to claim 2, wherein 0th-order diffracted light of the output light of the high-speed modulation means is output as output light of the laser modulation device. On the output side of the high speed modulation means, there is a correction means for correcting the output angle of the output light of the high speed modulation means,
3. The laser according to claim 2, wherein the first-order diffracted light of the output light of the high-speed modulation means is guided to a predetermined position via the correction means and is output as output light of the laser modulation device. Modulation device.   3. The high-speed modulation means further comprising another high-speed modulation means arranged in a direction to eliminate the wavelength dependence of the output angle of the output light of the high-speed modulation means. The laser modulation device described.   6. The laser modulation apparatus according to claim 2, wherein a plurality of the multi-wavelength modulation means are provided on an input side of the high-speed modulation means.   A microscope comprising the laser modulation device according to any one of claims 1 to 6.

Images