Patent ID: 7769262

Claim:
An optical compressor comprising at least one branch, the branch comprising: an optical device, arranged in an optical path, to receive pulse light from a first direction in a first part of the optical path, to pass the received pulse light through the optical device and continue in the first direction of a second part of the optical path, to receive returned pulse light from a second direction in the second part of the optical path, the second direction opposing the first direction, and to output the returned pulse light into a different optical path; an optical fiber of at least one kind, provided on the second part of the optical path, the optical fiber compressing the pulse light in the first direction and the second direction; and a polarization rotating element, provided on the second part of the optical path, the polarization rotating element rotating by 90 degrees a polarization direction of the pulse light received from the optical fiber in the first direction and returning the pulse light to the optical fiber in the second direction, wherein when said optical compressor comprises two or more branches, the branches are optically connected in series.