The invention relates to a position capturing device (60) for a light signal redirection device (34, 40) of an optical measurement apparatus (12) for capturing objects (18) in a monitoring region (16), to a light signal redirection device (34, 40), to an optical measurement apparatus (12) and to a method for operating a position capturing device (60). The position capturing device (60) is designed for providing at least one position signal (68) corresponding to a deflection (72) of at least one redirection region (42a, 42b) of the light signal redirection device (34, 40). The at least one redirection region (42a, 42b) is used to redirect at least one light signal (20, 22) and is rotatable at least in a partially circumferential manner with respect to at least one pivot (46) in at least one direction of rotation (48). The position capturing device (60) has at least one position region (62), which is mechanically coupled to the at least one redirection region (42a, 42b) of the light signal redirection device (34, 40) in a manner such that the at least one position region (62) can rotate jointly with the at least one redirection region (42a, 42b). The at least one position region (62) is designed to provide at least one position signal (68) corresponding to a deflection (72) of the at least one redirection region (42a, 42b). The at least one position region (62) has at least one diffractive structure (63), which is designed such that light signals (20) can be shaped to form position light signals (68) depending on their incidence (52, 53) on the at least one position region (62).