Abstract: A method for autofocusing a microscope at a correct autofocus position in a sample includes the steps: generating a reference pattern by an autofocus light device, projecting the reference pattern towards a sample, whereby the reference pattern is backscattered by at least two interfaces being located at or close to the sample, projecting the backscattered reference pattern towards a detector which provides spatial resolution, obtaining a superposition of a number of detection patterns, each detection pattern related to one of the interfaces, on the detector, analyzing the superposition of detection patterns to identify at least one autofocus detection pattern related to at least one of the interfaces, and analyzing the at least one autofocus detection pattern to determine the direction and/or magnitude of deviation of the microscope's current focus position from the correct focus position.

Abstract: A method for autofocusing a microscope at a correct autofocus position in a sample includes the steps: generating a reference pattern by an autofocus light device, projecting the reference pattern towards a sample, whereby the reference pattern is backscattered by at least two interfaces being located at or close to the sample, projecting the backscattered reference pattern towards a detector which provides spatial resolution, obtaining a superposition of a number of detection patterns, each detection pattern related to one of the interfaces, on the detector, analyzing the superposition of detection patterns to identify at least one autofocus detection pattern related to at least one of the interfaces, and analyzing the at least one autofocus detection pattern to determine the direction and/or magnitude of deviation of the microscope's current focus position from the correct focus position.

Abstract: The invention relates to a method for optically detecting at least one entity which is arranged on a substrate. The at least one entity is scanned with a measuring volume using at least one radiation source and a confocal optic. During a scanning process an auxiliary focus is generated by means of at least one second radiation source and a second optic. Radiation generated by the first radiation source is collimated by a first optic and radiation generated by the second radiation source is collimated by a second optic. A retroreflection from the auxiliary focus is detected by at least one detector and is used to measuring the position of an interface and, thus, for indirectly positioning the measuring volume. The position of the auxiliary focus relative to the measuring volume is adjustable in a defined manner.