Measuring intensity of EM radiation from source - using detector on axis of symmetry behind optical axicon

摘要

Measuring the intensity of the rotation symmetrical e.m. radiation from a source (1) at a defined angle to its axis of symmetry involves passing the emitted radiation via an optical wedge or axicon (2). The axicon's axis of symmetry is coincident with that of the field. The intensity of the radiation deflected along the symmetry axis and behind the wedge is measured by a detector (3) on the axis. The radiation angles corresponding to the intensity values are determined by a conventional equation related to the geometry of the arrangement. USE/ADVANTAGE - Laser aperture or field distribution at open end of cylindrical waveguide. Enables direct intensity measurement and hence low noise measurement of weak intensities of radiation at large angles.