A variable optical attenuator includes a first lens, a MEMS device, a second
lens,
and a wedge. The first lens is configured to collimate an input light received
on a first port and focus an output light on a focus point proximate to a second
port. The MEMS device includes a reflection surface having a tilting angle thereof
controllable by a control variable. The second lens has a focus point positioned
proximate to the reflection surface of the MEMS device. The wedge is positioned
between the first lens and the second lens and is configured to refract the input
light received from the first lens to enter the second lens and refract the output
light received from the second lens to enter the first lens.
