Varible optical attenuator

摘要

A mechanically-adjustable variable optical attenuator includes an azimuthally-tapering, rotatable beam attenuator. In a plane perpendicular to the light beam to be attenuated, the projection of the beam attenuator comprises a sharp distal tip, a proximal region, and a concave curved light-blocking surface narrowing from the proximal region to the distal tip. The extent of the beam attenuator obstructing the light beam is varied by rotating the beam attenuator about a rotation axis perpendicular to the light beam direction. The beam attenuator geometry allows achieving high resolutions while limiting the beam attenuator size. The attenuated light beam can be a single-mode or multi-mode light beam.