A method and arrangement for the depth-resolved optical detection of a specimen with an illumination light distribution of at least one wavelength generated on or in a specimen and detection particularly of the light that is influenced due to interaction with the specimen, particularly fluorescent light and/or reflected light and/or luminescent light and/or scattered and/or transmitted light, wherein the illumination light has a modulation in at least one spatial direction and the detection light which is modulated like the illumination light is spatially split into two components having a phase shift relative to one another, the components are measured separately and an optical section image of the specimen and/or of part of the specimen is calculated from them.