| 摘要 |
An apparatus (1) for forming a three-dimensional light intensity distribution displaying a spatially limited area of minimum light intensity that is enclosed by areas of high light intensity includes -two objectives (2, 3) focusing light coming out of opposite directions into a common focal area, -wherein light intensities of a first pair of coherent light beams (9, 10) extinguish each other in a first partial area of the focal area by destructive interference, -wherein beam paths (13, 14) of the first pair of coherent light beams (9, 10) pass through the two objectives (2, 3) in a first pair of partial areas of the pupils (40, 50) of the objectives (2, 3), -wherein light intensities of a second pair of coherent light beams (11, 12) extinguish each other in a second partial area of the focal area by destructive interference, -wherein beam paths (15, 16) of the second pair of coherent light beams (11, 12) pass through the two objectives (2, 3) in a second pair of partial areas of the pupils (40, 50) of the objectives (2, 3), -wherein the second pair of partial areas (42, 52) of the pupils (40, 50) are offset in rotation direction about a common optical axis (4) with regard to the first pair of partial areas of the pupils (40, 50), and -wherein the light of the second pair of coherent light beams (11, 12) does not interfere with the light of the first pair of coherent light beams (9, 10). |
