A variable optical attenuator for providing a new light attenuation mechanism
based
on using at least one of tilted mirrors to change and control the beam direction
of reflected light beam toward output optical port in a two dimensional light path
configuration is demonstrated to achieve the light attenuation in terms of changing
and controlling the coupling loss among input optical port, reflective tilted mirrors,
and output optical port. The tilted mirror is supported and connected by a suspended
flexure spring at one side. This suspended spring is connected with tilted mirror
at one side and is anchored on a substrate at the other side via a post (or a pivot).
When the tilted mirror is driven by an actuator to generate movement including
rotational mirror deflection and parallel mirror shifted displacement, the reflected
light beam path is changed according to the particular mirror positions. The attenuation
value is modified and controlled by the coupled light of reflected light beam to
output port. The structure and materials of variable optical attenuator is designed
and chose to be robust to environment mechanical and thermal noise.