Light-pad microscope for high-resolution 3D fluorescence imaging and 2D fluctuation spectroscopy

1. A microscope having an illumination light path for illuminating with an illumination light beam a sample through an illumination objective lens and at least one viewing light path for viewing the sample through a detection objective lens, the microscope comprising

a tube lens, arranged in the illumination light path, in front of the illumination objective lens,

an illumination light path focussing arrangement in the illumination light path in front of the tube lens, the illumination light path focussing arrangement including a cylindrical lens, which focusses the illumination light beam in one direction and leaves the illumination light beam unchanged in another direction transverse to the one direction, thus defining, at the intersection of the illumination light path and the detection light path, a substantially two-dimensional object illumination region extending along an illumination direction of the illumination light path and the other direction, and

an illumination region-confining device in the illumination light path arranged between the cylindrical lens and the illumination objective lens and for selectively illuminating a portion of the substantially two-dimensional object illumination region, the illumination region-confining device comprising a width confining slit and a length confining slit, the length confining slit being arranged between the tube lens and the illumination objective lens, wherein the portion of the substantially two-dimensional object illumination region is confined at least in the illumination direction and the other direction.

2. The microscope of claim 1 , wherein the illumination light path focussing arrangement further comprises at least one of (i) an anamorphically shaped lens, or (ii) a one-dimensional array of spherical or of aspherical lenses.

3. The microscope of claim 1 , wherein the illumination region-confining device comprises a light beam shaper.

4. The microscope of claim 1 , wherein a viewing direction of the at least one viewing light path is substantially perpendicular to the illumination direction and to the substantially two-dimensional object illumination region.

5. The microscope of claim 1 , further comprising an adjustable detection aperture in a detection path that allows to reduce an effectively viewed region in one or two dimensions.

6. The microscope of claim 5 , wherein the portion of the substantially two-dimensional object illumination region and the effectively viewed region are congruent and/or coincident.

7. The microscope of claim 6 , wherein the portion of the substantially two-dimensional object illumination region and the effectively viewed region are congruently and/or coincidently moveable through the sample.

8. The microscope of claim 1 , further comprising an additional objective lens for at least one of illumination or viewing of a sample arranged in a substantially two- dimensional object illumination region.

9. The microscope of claim 8 , wherein the additional objective lens is part of an epifluorescence microscope.

10. The microscope of claim 8 , wherein the microscope further comprises an inverted microscope and the additional objective lens is part of the inverted microscope.

11. The microscope of claim 1 , wherein the illumination region-confining device further comprises a scanning unit.

12. A method for detecting a sample, the method comprising:

Illuminating, by passing an illumination light beam through a tube lens and subsequently an illumination objective lens, a two-dimensional portion of a sample by focussing, with a cylindrical lens, the illumination light beam in one direction and leaving the illumination light beam unchanged in another direction transverse to the first direction, thus defining, at the intersection of the illumination light path and the detection light path, a substantially two- dimensional object illumination region extending in an illumination direction of the illumination light beam and in the other direction;

wherein illuminating the two-dimensional portion further comprises confining the substantially two-dimensional object illumination region, by an illumination region confining device in the illumination path arranged between the cylindrical lens and the illumination objective lens, for selectively illuminating a portion of the substantially two-dimensional object illumination region, the illumination region-confining device comprising a width confining slit and a length confining slit, the length confining slit being arranged between the tube lens and the illumination objective lens, wherein the portion of the substantially two-dimensional object illumination region is confined in the illumination direction and the other direction.

13. The method of claim 12 , further comprising viewing the substantially two- dimensional object illumination region in a viewing direction, the viewing direction being substantially perpendicular to the illumination direction.

14. The method of claim 12 , further comprising moving at least one of the substantially two-dimensional object illumination region or the portion of the substantially two-dimensional object illumination region through the sample.

15. The method of claim 12 , further comprising measuring a signal fluctuation in the portion of the substantially two-dimensional object illumination region.

16. The method of claim 12 , further comprising measuring a fluorescence intensity contrast for alignment.