Optical imaging system having an expand depth of field

1. An optical imaging system defining an optical beam path and comprising:

a beam deflecting unit for casting light rays out of an object region into an image plane;

an optical phase plate mounted in said optical beam path;

said phase plate being so configured that the Strehl ratio (H) of said system over a range of a distance parameter (ψ) is greater than the Strehl ratio of the system without said phase plate; and,

a generating unit for generating a geometric image of said image plane.

2. The optical imaging system of claim 1 , wherein said generating unit is configured as a unit for generating an image on the retina of a viewer's eye.

3. The optical imaging system of claim 1 , wherein said phase plate is so configured that the Strehl ratio (H) of said system for a distance parameter (ψ≧4) is greater than the Strehl ratio of said system without said phase plate.

4. The optical imaging system of claim 1 , wherein said optical phase plate imparts a phase offset (π≦ψ≦3π) to a light ray passing through said phase plate.

5. The optical imaging system of claim 1 , wherein said optical phase plate is designed to have a geometric phase deviation.

6. The optical imaging system of claim 1 , wherein said optical phase plate is configured as a cubic phase plate.

7. The optical imaging system of claim 1 , wherein said optical phase plate consists at least partially of glass.

8. The optical imaging system of claim 1 , wherein said optical phase plate consists at least partially of plastic.

9. The optical imaging system of claim 1 , wherein said optical phase plate consists at least partially of a glass substrate.

10. The optical imaging system of claim 1 , wherein said optical phase plate includes a vaporized coating.

11. The optical imaging system of claim 10 , wherein said vaporized coating on said phase plate has a thickness which varies locally.

12. The optical imaging system of claim 1 , wherein said phase plate consists at least partially of an electrostatically deformable membrane.

13. The optical imaging system of claim 1 , wherein said optical phase plate consists at least partially of a liquid crystal display.

14. The optical imaging system of claim 1 , wherein said optical imaging system is designed for a microscope including a surgical microscope.

15. The optical imaging system of claim 1 , wherein said optical imaging system has a resolution which is adapted to the resolution capacity of a human eye.

16. The optical imaging system of claim 1 , wherein said phase plate can be moved into and out of said beam path.

17. An optical imaging system defining an optical beam path and comprising:

a beam deflecting unit for casting light rays out of a region of an object into an image plane;

an optical phase plate mounted in said optical beam path;

a generating unit for generating a geometric image of said image plane;

an objective lens mounted in said beam path;

said objective lens having a first side facing away from said object and a second side facing toward said object; and,

said optical phase plate being mounted on one of said sides of said objective lens.

18. The optical imaging system of claim 17 , wherein said phase plate is so configured that the Strehl ratio (H) of said system over a range of a distance parameter (ψ) is greater than the Strehl ratio of the system without said phase plate.

19. The optical imaging system of claim 18 , wherein said phase plate is so configured that the Strehl ratio (H) of said system for a distance parameter (ψ≧4) is greater than the Strehl ratio of said system without said phase plate.

20. The optical imaging system of claim 17 , wherein said optical phase plate imparts a phase offset (π≦φ≦3π) to a light ray passing through said phase plate.

21. The optical imaging system of claim 17 , wherein said optical phase plate is designed to have a geometric phase deviation.

22. The optical imaging system of claim 17 , wherein said optical phase plate is configured as a cubic phase plate.

23. The optical imaging system of claim 17 , wherein said optical phase plate consists at least partially of glass.

24. The optical imaging system of claim 17 , wherein said optical phase plate consists at least partially of plastic.

25. The optical imaging system of claim 17 , wherein said optical phase plate consists at least partially of a glass substrate.

26. The optical imaging system of claim 17 , wherein said optical phase plate includes a vaporized coating.

27. The optical imaging system of claim 26 , wherein said vaporized coating on said phase plate has a thickness which varies locally.

28. The optical imaging system of claim 17 , wherein said phase plate consists at least partially of an electrostatically deformable membrane.

29. The optical imaging system of claim 17 , wherein said optical phase plate consists at least partially of a liquid crystal display.

30. The optical imaging system of claim 17 , wherein said optical imaging system is designed for a microscope including a surgical microscope.

31. The optical imaging system of claim 17 , wherein said optical imaging system has a resolution which is adapted to the resolution capacity of a human eye.

32. The optical imaging system of claim 17 , wherein said phase plate can be moved into and Out of said beam path.

33. An optical imaging system defining an optical beam path and comprising:

a beam deflecting unit for casting light rays out of an object region into an image plane;

an optical phase plate mounted in said optical beam path;

a generating unit for generating a geometric image of said image plane; and,

said optical phase plate being mounted in a region of said optical imaging system wherein the imaging beam path is parallel.

34. The optical imaging system of claim 33 , wherein said phase plate is so configured that the Strehl ratio (H) of said system over a range of a distance parameter (ψ) is greater than the Strehl ratio of the system without said phase plate.

35. The optical imaging system of claim 34 , wherein said phase plate is so configured that the Strehl ratio (H) of said system for a distance parameter (ψ≧4) is greater than the Strehl ratio of said system without said phase plate.

36. The optical imaging system of claim 33 , wherein said optical phase plate imparts a phase offset (π≦φ≦3π) to a light ray passing through said phase plate.

37. The optical imaging system of claim 33 , wherein said optical phase plate is designed to have a geometric phase deviation.

38. The optical imaging system of claim 33 , wherein said optical phase plate is configured as a cubic phase plate.

39. The optical imaging system of claim 33 , wherein said optical phase plate consists at least partially of glass.

40. The optical imaging system of claim 33 , wherein said optical phase plate consists at least partially of plastic.

41. The optical imaging system of claim 33 , wherein said optical phase plate consists at least partially of a glass substrate.

42. The optical imaging system of claim 33 , wherein said optical phase plate includes a vaporized coating.

43. The optical imaging system of claim 42 , wherein said vaporized coating on said phase plate has a thickness which varies locally.

44. The optical imaging system of claim 33 , wherein said phase plate consists at least partially of an electrostatically deformable membrane.

45. The optical imaging system of claim 33 , wherein said optical phase plate consists at least partially of a liquid crystal display.

46. The optical imaging system of claim 33 , wherein said optical imaging system is designed for a microscope including a surgical microscope.

47. The optical imaging system of claim 33 , wherein said optical imaging system has a resolution which is adapted to the resolution capacity of a human eye.

48. The optical imaging system of claim 33 , wherein said phase plate can be moved into and out of said beam path.