Three-dimensional imaging using swept, confocally aligned planar excitation and a customized image splitter

1. An imaging apparatus comprising:

a first set of optical components having a proximal end and a distal end, wherein the first set of optical components includes a first objective disposed at the distal end of the first set of optical components;

a second set of optical components having a proximal end and a distal end, wherein the second set of optical components includes a second objective disposed at the distal end of the second set of optical components;

a scanning element that is disposed proximally with respect to the proximal end of the first set of optical components and proximally with respect to the proximal end of the second set of optical components,

wherein the scanning element is arranged to route a sheet of excitation light so that the sheet of excitation light will pass through the first set of optical components in a proximal to distal direction and project into a sample that is positioned distally beyond the distal end of the first set of optical components, wherein the sheet of excitation light is projected into the sample at an oblique angle, and wherein the sheet of excitation light is projected into the sample at a position that varies depending on an orientation of the scanning element,

wherein the first set of optical components routes detection light from the sample in a distal to proximal direction back to the scanning element, and

wherein the scanning element is also arranged to route the detection light so that the detection light will pass through the second set of optical components in a proximal to distal direction and form an intermediate image plane at a position that is distally beyond the distal end of the second set of optical components;

a third objective arranged to route light arriving from the intermediate image plane to an infinity space, wherein the intermediate image plane is disposed in front of the third objective and the infinity space is disposed behind the third objective;

a first beam splitter positioned in the infinity space, wherein the first beam splitter is arranged to route light from the intermediate image plane having a first wavelength in a first direction and to route light from the intermediate image plane having a second wavelength in a second direction, wherein the second direction is different from the first direction and wherein the first wavelength is longer than the second wavelength;

a first light detector array arranged to capture first-wavelength images;

a second light detector array arranged to capture second-wavelength images; and

a third set of optical components arranged to route the light having the first wavelength that exits the first beam splitter towards the first light detector array and route the light having the second wavelength that exits the first beam splitter towards the second light detector array.

2. The apparatus of claim 1 , wherein the third set of optical components includes:

a second beam splitter;

a first steering mirror arranged to route the light having the first wavelength that exits the first beam splitter into the second beam splitter;

a second steering mirror arranged to route the light having the second wavelength that exits the first beam splitter into the second beam splitter; and

at least one lens disposed between (a) the second beam splitter and (b) the first and second light detector arrays,

wherein the second beam splitter is arranged to route light arriving from the first and second steering mirrors towards the at least one lens, and

wherein the first beam splitter comprises a long-pass dichroic element that passes light at the first wavelength without diverting its path, and redirects light at the second wavelength in the second direction, and

wherein the second beam splitter comprises a long-pass dichroic element that passes light at the first wavelength without diverting its path, and redirects light at the second wavelength arriving from the second steering mirror towards the at least one lens, and

wherein each of the first beam splitter and the second beam splitter are implemented in a respective movable module, and

wherein the apparatus further comprises (i) a first optical block, (ii) a mechanism for moving the first beam splitter out of a first optical path and moving the first optical block into the first optical path; (iii) a second optical block, and (iv) a mechanism for moving the second beam splitter out of a second optical path and moving the second optical block into the second optical path.

3. The apparatus of claim 1 , wherein the third set of optical components includes:

a second beam splitter;

a first steering mirror arranged to route the light having the first wavelength that exits the first beam splitter into the second beam splitter;

a second steering mirror arranged to route the light having the second wavelength that exits the first beam splitter into the second beam splitter; and

at least one lens disposed between (a) the second beam splitter and (b) the first and second light detector arrays, and

wherein the second beam splitter is arranged to route light arriving from the first and second steering mirrors towards the at least one lens, and

wherein the first beam splitter comprises a long-pass dichroic element that passes light at the first wavelength without diverting its path, and redirects light at the second wavelength in the second direction, and

wherein the second beam splitter comprises a short-pass dichroic element that passes light at the second wavelength without diverting its path, and redirects light at the first wavelength arriving from the first steering mirror towards the at least one lens, and

wherein each of the first beam splitter and the second beam splitter are implemented in a respective movable module, and

wherein the apparatus further comprises (i) a first optical block, (ii) a mechanism for moving the first beam splitter out of a first optical path and moving the first optical block into the first optical path; (iii) a second optical block comprising a mirror, and (iv) a mechanism for moving the second beam splitter out of a second optical path and moving the second optical block into the second optical path.

4. The apparatus of claim 1 , wherein the third set of optical components includes:

a second beam splitter;

a first steering mirror arranged to route the light having the first wavelength that exits the first beam splitter into the second beam splitter;

a second steering mirror arranged to route the light having the second wavelength that exits the first beam splitter into the second beam splitter; and

at least one lens disposed between (a) the second beam splitter and (b) the first and second light detector arrays,

wherein the second beam splitter is arranged to route light arriving from the first and second steering mirrors towards the at least one lens, and

wherein light that exits the second beam splitter is perpendicular, ±30°, to a plane defined by (a) an optical axis of the first set of optical components and (b) an optical axis of the second set of optical components.

5. The apparatus of claim 1 , wherein the third set of optical components includes:

a second beam splitter;

a first steering mirror arranged to route the light having the first wavelength that exits the first beam splitter into the second beam splitter;

a second steering mirror arranged to route the light having the second wavelength that exits the first beam splitter into the second beam splitter; and

at least one lens disposed between (a) the second beam splitter and (b) the first and second light detector arrays,

wherein the second beam splitter is arranged to route light arriving from the first and second steering mirrors towards the at least one lens, and

wherein light that exits the second beam splitter is perpendicular, ±15°, to a plane defined by (a) an optical axis of the first set of optical components and (b) an optical axis of the second set of optical components.

6. An imaging apparatus comprising:

an optical system that (a) projects a sheet of excitation light into a sample at an oblique angle, wherein a position of the sheet of excitation light within the sample varies depending on an orientation of a scanning element, and (b) forms, from detection light that originates from the position of the sheet of excitation light, an image at an intermediate image plane, wherein the intermediate image plane remains stationary regardless of the orientation of the scanning element;

a third objective arranged to route light arriving from the intermediate image plane to an infinity space, wherein the intermediate image plane is disposed in front of the third objective and the infinity space is disposed behind the third objective;

a first beam splitter positioned in the infinity space, wherein the first beam splitter is arranged to route light from the intermediate image plane having a first wavelength in a first direction and to route light from the intermediate image plane having a second wavelength in a second direction, wherein the second direction is different from the first direction and wherein the first wavelength is longer than the second wavelength;

a first light detector array arranged to capture first-wavelength images;

a second light detector array arranged to capture second-wavelength images; and

a third set of optical components arranged to route the light having the first wavelength that exits the first beam splitter towards the first light detector array and route the light having the second wavelength that exits the first beam splitter towards the second light detector array.

7. The apparatus of claim 6 , wherein the first light detector array and the second light detector array are implemented on separate regions of a single light detector chip.

8. The apparatus of claim 6 , wherein the third set of optical components includes:

a second beam splitter;

a first steering mirror arranged to route the light having the first wavelength that exits the first beam splitter into the second beam splitter;

a second steering mirror arranged to route the light having the second wavelength that exits the first beam splitter into the second beam splitter; and

at least one lens disposed between (a) the second beam splitter and (b) the first and second light detector arrays,

wherein the second beam splitter is arranged to route light arriving from the first and second steering mirrors towards the at least one lens.

9. The apparatus of claim 8 , wherein the first beam splitter comprises a long-pass dichroic element that passes light at the first wavelength without diverting its path, and redirects light at the second wavelength in the second direction, and

wherein the second beam splitter comprises a long-pass dichroic element that passes light at the first wavelength without diverting its path, and redirects light at the second wavelength arriving from the second steering mirror towards the at least one lens.

10. The apparatus of claim 9 , wherein each of the first beam splitter and the second beam splitter are implemented in a respective movable module, and

wherein the apparatus further comprises (i) a first optical block, (ii) a mechanism for moving the first beam splitter out of a first optical path and moving the first optical block into the first optical path; (iii) a second optical block, and (iv) a mechanism for moving the second beam splitter out of a second optical path and moving the second optical block into the second optical path.

11. The apparatus of claim 8 , wherein the first beam splitter comprises a long-pass dichroic element that passes light at the first wavelength without diverting its path, and redirects light at the second wavelength in the second direction, and

wherein the second beam splitter comprises a short-pass dichroic element that passes light at the second wavelength without diverting its path, and redirects light at the first wavelength arriving from the first steering mirror towards the at least one lens.

12. The apparatus of claim 11 , wherein each of the first beam splitter and the second beam splitter are implemented in a respective movable module, and

wherein the apparatus further comprises (i) a first optical block, (ii) a mechanism for moving the first beam splitter out of a first optical path and moving the first optical block into the first optical path; (iii) a second optical block comprising a mirror, and (iv) a mechanism for moving the second beam splitter out of a second optical path and moving the second optical block into the second optical path.

13. The apparatus of claim 8 , wherein at least one of the first and second steering mirrors has an orientation that is adjustable.

14. The apparatus of claim 13 , wherein at least one of the first and second steering mirrors has a position that is adjustable.

15. The apparatus of claim 14 , wherein the first light detector array and the second light detector array are implemented on separate regions of a single light detector chip.

16. The apparatus of claim 8 , wherein light that exits the second beam splitter deviates by less than 15° from a plane defined by (a) an optical axis of the excitation light and (b) an optical axis of the detection light.

17. The apparatus of claim 8 , wherein light that exits the second beam splitter is perpendicular, ±30°, to a plane defined by (a) an optical axis of the excitation light and (b) an optical axis of the detection light.

18. The apparatus of claim 8 , wherein light that exits the second beam splitter is perpendicular, ±15°, to a plane defined by (a) an optical axis of the excitation light and (b) an optical axis of the detection light.

19. The apparatus of claim 8 , wherein each of the first beam splitter and the second beam splitter are implemented in a respective removable magnetically-mounted module.

20. The apparatus of claim 6 , wherein the first beam splitter is implemented in a removable magnetically-mounted module.