Observation device including illumination optical system and extraction unit and observation method

1. An observation device, comprising:

an illumination optical system configured to collect (i) a first illuminating light, which has a first optical frequency ω 1 , on a first region of an observation object, (ii) a second illuminating light, which has having a second optical frequency ω 2 ′, on a second region partially overlapping the first region, and (iii) a third illuminating light, which has a third optical frequency ω 2 , on a third region that contains a non-overlap region, which is a region of the first region that does not overlap the second region; and

an extraction unit configured to extract a signal light, which has an optical frequency ω 2 and is generated in accordance with a change in an energy level of a substance of the observation object in the non-overlap region, from light generated in all of the first region, the second region, and the third region, wherein:

the illumination optical system is configured to sequentially emit the first illuminating light, the second illuminating light, and the third illuminating light to the observation object; and

the extraction unit is configured (i) to modulate a property of the first illuminating light heading toward the observation object at a frequency f 1 to a time direction and (ii) to limit a generation origin of the signal light to be extracted to the non-overlap region by lock-in detecting the light generated in all of the first, second, and third regions at the frequency f 1 .

2. The observation device according to claim 1 , wherein:

the extraction unit is configured to provide an optical frequency difference between the second illuminating light and the third illuminating light heading toward the observation object, and

the extraction unit is configured to prevent a mixture of the second illuminating light into the signal light to be extracted by blocking a light at the second optical frequency ω 2 ′ at a downstream side of the observation object.

3. The observation device according to claim 1 , wherein:

the extraction unit is configured to provide a polarization direction difference between the second illuminating light and the third illuminating light heading toward the observation object, and

the extraction unit is configured to prevent a mixture of the second illuminating light into the signal light to be extracted by blocking a light in the same polarization direction as a polarization direction of the second illuminating light at a downstream side of the observation object.

4. The observation device according to claim 1 , wherein

the modulated property of the first illuminating light is one of an intensity, a phase, polarization, and an optical frequency of the light.

5. The observation device according to claim 1 , wherein:

shapes of the first region and the third region are circular;

a shape of the second region is a ring-belt shape; and

a center of the first region, a center of the second region, and a center of the third region coincide with each other.

6. An observation method, comprising:

collecting a first illuminating light, which has a first optical frequency ω 1 , on a first region of an observation object;

collecting a second illuminating light, which has a second optical frequency ω 2 ′, on a second region partially overlapping the first region;

collecting a third illuminating light, which has a third optical frequency ω 1 , on a third region containing that contains a non-overlap region, which is a region of the first region that does not overlap the second region;

extracting a signal light, which has an optical frequency ω 2 and is generated in accordance with a change in an energy level of a substance of the observation object in the non-overlap region, from light generated in all of the first region, the second region, and the third region;

sequentially emitting the first illuminating light, the second illuminating light, and the third illuminating light to the observation object;

modulating a property of the first illuminating light heading toward the observation object at a frequency f 1 to a time direction; and

limiting a generation origin of the signal light to be extracted to the non-overlap region by lock-in detecting the light generated in all of the first, second, and third regions at the frequency f 1 .

7. An observation device, comprising:

an illumination optical system configured to collect (i) a first illuminating light, which has a first optical frequency ω 1 , on a first region of an observation object, (ii) a second illuminating light, which has a second optical frequency ω 2 ′, on a second region partially overlapping the first region, and (iii) a third illuminating light, which has a third optical frequency ω 2 , on a third region that contains a non-overlap region, which is a region of the first region that does not overlap the second region; and

an extraction unit configured to extract a signal light, which has an optical frequency ω 2 and is generated in accordance with a change in an energy level of a substance of the observation object in the non-overlap region, from light generated in all of the first region, the second region, and the third region, wherein

the illumination optical system is configured to emit either (i) the third illuminating light after emitting the first illuminating light and the second illuminating light simultaneously or (ii) the first illuminating light, the second illuminating light, and the third illuminating light simultaneously in a state where a wavelength difference of 3600 cm −1 or more is provided between the first illuminating light and the third illuminating light.

8. The observation device according to claim 7 , wherein:

the extraction unit is configured to provide an optical frequency difference between the second illuminating light and the third illuminating light heading toward the observation object, and

the extraction unit is configured to prevent a mixture of the second illuminating light into the signal light to be extracted by blocking a light at the second optical frequency ω 2 ′ at a downstream side of the observation object.

9. The observation device according to claim 7 , wherein:

the extraction unit is configured to provide a polarization direction difference between the second illuminating light and the third illuminating light heading toward the observation object, and

the extraction unit is configured to prevent a mixture of the second illuminating light into the signal light to be extracted by blocking a light in the same polarization direction as a polarization direction of the second illuminating light at a downstream side of the observation object.

10. An observation device, comprising:

an illumination optical system configured to collect (i) a first illuminating light, which has a first optical frequency ω 1 , on a first region of an observation object, (ii) a second illuminating light, which has a second optical frequency ω 2 ′, on a second region partially overlapping the first region, and (iii) a third illuminating light, which has a third optical frequency ω 2 , on a third region that contains a non-overlap region, which is a region of the first region that does not overlap the second region; and

an extraction unit configured to extract a signal light, which has an optical frequency (2ω 1 -ω 2 ) and is generated in accordance with a change in an energy level of a substance of the observation object in the non-overlap region, from light generated in all of the first region, the second region, and the third region, wherein

the illumination optical system is configured to simultaneously emit the first illuminating light, the second illuminating light, and the third illuminating light to the observation object.

11. The observation device according to claim 10 , wherein:

the extraction unit is configured to provide a polarization direction difference between the second illuminating light and the third illuminating light heading toward the observation object, and

the extraction unit is configured to limit a generation origin of the signal light to be extracted to the non-overlap region by blocking a light in the same polarization direction as a combined polarization direction of the second illuminating light and the third illuminating light at a downstream side of the observation object.

12. The observation device according to claim 10 , wherein

the extraction unit is configured (i) to modulate a property of the first illuminating light heading toward the observation object at a frequency f 1 to a time direction, (ii) to modulate a property of the third illuminating light heading toward the observation object at a frequency f 2 to the time direction, and (iii) to limit a generation origin of the signal light to be extracted to the non-overlap region by lock-in detecting the light generated in all of the first, second, and third regions at one of frequencies f 2 , |f 1 ±f 2 |, and |2f 1 ±f 2 |.

13. An observation device, comprising:

an illumination optical system configured to collect (i) a first illuminating light, which has a first optical frequency ω 1 , on a first region of an observation object, (ii) a second illuminating light, which has a second optical frequency ω 2 ′, on a second region partially overlapping the first region, and (iii) a third illuminating light, which has a third optical frequency ω 2 , on a third region that contains a non-overlap region, which is a region of the first region that does not overlap the second region; and

an extraction unit configured to extract a signal light, which has an optical frequency (2ω 2 -ω 1 ) and is generated in accordance with a change in an energy level of a substance of the observation object in the non-overlap region, from light generated in all of the first region, the second region, and the third region, wherein

the illumination optical system is configured to simultaneously emit the first illuminating light, the second illuminating light, and the third illuminating light to the observation object.

14. The observation device according to claim 13 , wherein:

the extraction unit is configured to provide a polarization direction difference between the second illuminating light and the third illuminating light heading toward the observation object, and

the extraction unit is configured to limit a generation origin of the signal light to be extracted to the non-overlap region by blocking a light in the same polarization direction as a combined polarization direction of the second illuminating light and the third illuminating light at a downstream side of the observation object.

15. The observation device according to claim 13 , wherein

the extraction unit is configured (i) to modulate a property of the first illuminating light heading toward the observation object at a frequency f 1 to a time direction, (ii) to modulate a property of the third illuminating light heading toward the observation object at a frequency f 2 to the time direction, and (iii) to limit a generation origin of the signal light to be extracted to the non-overlap region by lock-in detecting the light generated in all of the first, second, and third regions at one of frequencies f 1 , |f 2 ±f 1 |, and |2f 2 ±f 1 |.

16. An observation device, comprising:

an illumination optical system configured to collect (i) a first illuminating light, which has a first optical frequency ω 1 , on a first region of an observation object, (ii) a second illuminating light, which has a second optical frequency ω 2 ′, on a second region partially overlapping the first region, and (iii) a third illuminating light, which has a third optical frequency ω 2 , on a third region that contains a non-overlap region, which is a region of the first region that does not overlap the second region; and

an extraction unit configured to extract a signal light, which has an optical frequency of one of ω 2 and ω 1 and is generated in accordance with a change in an energy level of a substance of the observation object in the non-overlap region, from light generated in all of the first region, the second region, and the third region, wherein

the illumination optical system is configured to simultaneously emit the first illuminating light, the second illuminating light, and the third illuminating light to the observation object.

17. The observation device according to claim 16 , wherein:

the extraction unit is configured to provide a polarization direction difference between the second illuminating light and the third illuminating light heading toward the observation object, and

the extraction unit is configured to limit a generation origin of the signal light to be extracted to the non-overlap region by blocking a light in the same polarization direction as a combined polarization direction of the second illuminating light and the third illuminating light at a downstream side of the observation object.

18. The observation device according to claim 16 , wherein

the extraction unit is configured (i) to modulate a property of the first illuminating light heading toward the observation object at a frequency f 1 to a time direction, (ii) to modulate a property of the third illuminating light heading toward the observation object at a frequency f 2 to the time direction, and (iii) to limit a generation origin of the signal light to be extracted to the non-overlap region by lock-in detecting the light generated in all of the first, second, and third regions at a frequency |f 1 ±f 2 |.