Patent ID: 8238697

Claim:
An optical structure, comprising: a polarization beam splitter comprising an input end, and an output end having a first output and a second output; a polarization rotator system comprising a first polarization rotator having an input end and an output end, and a second polarization rotator having an input end and an output end; and a polarization beam combiner comprising an input end having first and second inputs, and an output end; and a first optical path including the first output of the polarization beam splitter, the input end of the first polarization rotator, the output end of the first polarization rotator, and the first input of the polarization beam combiner, the first optical path being configured such that first light propagates along the first optical path from the first output of the polarization beam splitter to the first input of the polarization beam combiner through the first polarization rotator; and a second optical path including the second output of the polarization beam splitter, the input end of the second polarization rotator, the output end of the second polarization rotator, and the second input of the polarization beam combiner, the second optical path being configured such that second light propagates along the second optical path from the second output of the polarization beam splitter to the second input of the polarization beam combiner through the second polarization rotator, wherein the first polarization rotator is spaced from the second optical path and the second polarization rotator is spaced from the first optical path.