Patent ID: 8111994

Claim:
An interferometer system comprising: a first splitter/combiner element (SCE) having an input port, an output port, a first bi-directional port, and a second bi-directional port, the first SCE configured to (i) split an input signal received at the input port into a first portion of light for exit at the first bi-directional port and a second portion of light for exit at the second bi-directional port and (ii) combine signals received at the first and second bi-directional ports into an output signal at the output port; a first optical path for communicating the first portion of light from the first bi-directional port of the first SCE through an optical device and to the second bi-directional port of the first SCE at an operating wavelength; and a second optical path for communicating the second portion of light from the second bi-directional port of the first SCE through the optical device and to the first bi-directional port of the first SCE at the operating wavelength, wherein there is a non-overlapping portion, in the optical device, between the first and second optical paths such that the first and second portions of light split from the input signal by the first SCE among the first and second bi-directional ports always travel simultaneously along two at least partially non-overlapping paths, and wherein a substantial portion of the first portion of light at the operating wavelength that exits the first SCE through the first bi-directional port re-enters the first SCE through the second bi-directional port.