Optical cavity for exclusively receiving light parallel to an optical axis

摘要

A tube (1) is shown for coupling with, in particular, optical transmitter and/or receiver elements (2), and with means for suppressing interfering radiation, in which the means for suppressing interfering radiation consist of multiply reflecting surfaces (15) which absorb interfering radiation and which are formed by a plurality of ribs (11) which respectively extend substantially along a plane extending through the optical axis of the tube (1).