Optical system with a tilted illumination plane and method for illuminating a sample volume in an optical system with a tilted illumination plane

1. An optical system, comprising:

an illumination device configured to generate illumination light comprising a light sheet;

a scanning device comprising a focal-length-variable illumination and detection optical unit having an optical axis, the scanning device being configured to generate a temporal sequence of at least two tilted illumination planes for illuminating a stationary sample volume, the at least two tilted illumination planes being tilted with respect to the optical axis and arranged at a distance from one another and parallel to one another; and

an erecting optical unit configured to image an image of the at least two tilted illumination planes in a planar manner in a detector plane.

2. The optical system as claimed in claim 1 , wherein the scanning device has no mirrors.

3. The optical system as claimed in claim 1 , wherein the focal-length-variable illumination and detection optical unit is configured for transmission of the illumination light to the sample volume and for transmission of scattered and/or fluorescent light from the sample volume into the erecting optical unit.

4. The optical system as claimed in claim 3 , wherein the illumination and detection optical unit comprises a focal-length-variable optical element.

5. The optical system as claimed in claim 4 , wherein the focal-length-variable optical element is configured as an electronically tunable lens.

6. The optical system as claimed in claim 4 , wherein the focal-length-variable optical element is arranged in a pupil of the illumination and detection optical unit.

7. The optical system as claimed in claim 4 , wherein a telescope is disposed in the illumination and detection optical unit, the telescope being configured to image a pupil of a partial optical unit of the illumination and detection optical unit, and

wherein the focal-length-variable optical element is arranged in a position of the imaging of the pupil.

8. The optical system as claimed in claim 4 , further comprising:

a further focal-length-variable optical element,

wherein a magnification of the optical system is changeable by the further focal-length-variable optical element.

9. The optical system as claimed in claim 3 , wherein the illumination device and the erecting optical unit are configured to be rotatable with one another about the optical axis.

10. A method for illuminating a sample volume, the method comprising:

generating illumination light comprising a light sheet;

offsetting, by a scanning device comprising a focal-length-variable illumination and detection optical unit having an optical axis, a temporal sequence of tilted illumination planes representing the light sheet in a stationary sample volume parallel to one another, the tilted illumination planes being tilted with respect to the optical axis; and

using an erecting optical unit to image an image of the at least two tilted illumination planes in a planar manner in a detector plane.

11. The method as claimed in claim 10 , further comprising jointly rotating an illumination device and the erecting optical unit about an optical axis of the scanning device so as to illuminate the sample volume from different directions.

12. The method as claimed in claim 10 , further comprising:

feeding illumination light of an illumination device into the scanning device and transmitting the illumination light along a non-paraxial illumination path;

transmitting the illumination light through the scanning device and varying convergence or divergence of the illumination light by the scanning device;

illuminating the sample volume with the tilted illumination planes, wherein varying the convergence or divergence of the illumination light by the scanning device brings about parallel displacement of the tilted illumination planes along the optical axis;

collecting scattered and/or fluorescent light from the sample volume by the scanning device and transmitting the scattered and/or fluorescent light along a non-paraxial detection path by the scanning device; and

erecting the scattered and/or fluorescent light by the erecting optical unit.

13. The method according to claim 10 , wherein the sample volume is in an optical system.