Variable optical attenuator

A variable optical attenuator, comprising:

• a housing;
• a motor mounted within said housing, said motor having a drive shaft;
• a filter mounted on said drive shaft such that said drive shaft passes through a substantially center point of said filter, said filter having a filter gradient that begins at a first filter edge and gradually increases in optical density across said filter toward a second filter edge diametrically opposed from said first filter edge;
• and
• an input optical fiber providing a light signal to be attenuated, said input optical fiber aimed such that said light signal passes through a first collimator, said filter, and a second collimator, to an output optical fiber;
• wherein said motor rotates said drive shaft to position said filter to a desired attenuation position for attenuation of said light signal.

A method of variably attenuating an optical signal, comprising the steps of:

• receiving a light signal from an input fiber and collimator;
• directing said light signal through a substantially circular filter element having a filter gradient that begins at a first filter edge and gradually increases in optical density across said filter element toward a second filter edge diametrically opposed from said first filter edge location;
• actuating a motor to rotate a drive shaft and said filter element to a desired attenuation level within said filter gradient;
• receiving an attenuated light signal in an output fiber and collimator.

A variable optical attenuator, comprising:

• a housing;
• a motor mounted within said housing, said motor having a drive shaft;
• a filter mounted within said housing, such that said drive shaft drives said filter to control filter position, said filter having a filter gradient that begins at a first filter edge and gradually increases in optical density across said filter toward a second filter edge;
• and
• an input optical fiber providing a light signal to be attenuated, said input optical fiber aimed such that said light signal passes through a first collimator, said filter, and a second collimator, to an output optical fiber;
• wherein said motor rotates said drive shaft to position said filter to a desired attenuation position for attenuation of said light signal.

A variable optical attenuator, comprising:

• a sealed housing;
• a motor mounted within said housing, said motor having a drive shaft;
• a filter mounted on said drive shaft such that said drive shaft passes through a substantially center point of said filter, said filter having a filter gradient that begins at a first filter edge and gradually increases in optical density across said filter toward a second filter edge diametrically opposed from said first filter edge;
• and
• an input optical fiber providing a light signal to be attenuated, said input optical fiber aimed such that said light signal passes through a first collimator, said filter, and a second collimator, to an output optical fiber;
• wherein said motor rotates said drive shaft to position said filter to a desired attenuation position for attenuation of said light signal.