Patent ID: 8294981

Claim:
An optical system comprising: an optical amplifier, the optical amplifier having an optical path, wherein the optical path is folded resulting in a first optical path segment and a second optical path segment, and a gain flattening filter (GFF) with portions of the GFF adapted to be selectively inserted to intersect the first optical path segment and other portions of the GFF adapted to be selectively inserted to intersect the second optical path segment, wherein the GFF comprises: a first actuating arm comprising a first GAF and a second GAF, wherein the first actuating arm is movable between a first position where the first GAF intersects the first optical path segment and the second GAF intersects the second optical path segment, a second position where the first GAF intersects the first optical path segment and the second GAF intersects neither optical path segment, and a third position where the first GAF intersects neither optical path segment and the second GAF intersects the second optical path segment, and a second actuating arm comprising a third GAF and a fourth GAF, wherein the second actuating arm is movable between a first position where the third GAF intersects the first optical path segment and the fourth GAF intersects the second optical path segment, a second position where the third GAF intersects the first optical path segment and the fourth GAF intersects neither optical path segment, and a third position where the third GAF intersects neither optical path segment and the fourth GAF intersects the second optical path segment.