| 摘要 |
The invention relates to an optical device (31) for determining the in-focus position of a Fourier optics set-up (3, 9, 13), comprising: a beamsplitter (33), a numerical aperture delimiting diaphragm (35), an imaging system (41, 43), and a one or two dimensional detector (45), which are arranged and configured such that the detector is at an optically conjugated position with respect to the in-focus position (37a) of the Fourier optics set-up and such that the field of view of the optical device is larger than an illumination spot size or light emission spot size on the surface of a sample to be positioned in the in-focus position of the Fourier optics set-up, wherein the beamsplitter has a predetermined angle (8) configured to select a light beam emitted from the surface (7) of the sample (5) under a predetermined emission angle (alpha) in conjunction with the numerical aperture delimiting diaphragm and the imaging system to direct the selected light beam onto the detector such that depending on the position of the sample (63, 65, 67) with respect to the in-focus position of the Fourier optics set-up the selected light beam is detected at different positions on the one or two dimensional detector. The invention further more relates to a corresponding method for determining the in-focus position. In addition an imaging device and a Fourier optics set-up comprising the optical device and/or at least two imaging devices are provided. |
