Variable optical attenuator

A variable optical attenuator for attenuating optical signals input from an input optical fiber and output to an output optical fiber, comprising:

• a housing with an interior space therein and at least one side hole positioned at one side of the housing and communicating with said interior space;
• an optical module comprising a frame for mounting a reflector, and a collimator for fixing said fibers;
• a filter having a filter density which varies between a lower density region and a higher density region;
• and
• a reciprocating means coupled to the filter which provides a stable linear movement of itself and the filter, wherein said reciprocating means has at least two adjusting controls and further comprises a carrier for mounting the filter, a stopper for restraining the movement of said carrier, and a screw rod, wherein said screw rod rotatably and threadedly engages with said side hole of the housing, the stopper and the carrier, whereby the optical module and the reciprocating means received in the interior space of the housing.

A variable optical attenuator comprising:

• a housing;
• a filter positioned in the housing, said filter defining a varying optical density gradient along a transverse direction perpendicular to a light path direction;
• reciprocating means moving said filter along said transverse direction;
• and
• Two opposite controls disposed and exposed on two opposite transverse sides of the housing along said transverse direction to adjustably move said reciprocating means with accessibility from said two sides, respectively.