Patent ID: 7366419

Claim:
Apparatus for isolating transmit and receive optical beams in an optical communication system, wherein the transmit and receive optical beams are of different wavelengths, the apparatus comprising: an annular mirror having a receive beam region and a center aperture; a first steering mirror; a dichroic beam splitter oriented and located to receive the transmit optical beam through the center aperture of the annular mirror and to reflect the transmit beam along a transmit path; wherein the dichroic beam splitter is oriented and located to receive the receive optical beam along a receive path and to pass the receive optical beam to the first steering mirror; wherein the first steering mirror is oriented and located to receive the receive optical beam from the dichroic beam splitter and to reflect the receive optical beam to the receive beam region of the annular mirror, wherein the steering mirror effects a desired degree of angular separation between the transmit optical beam and the receive optical beam; means for orienting and positioning the annular mirror such that the receive optical beam impinges on the receive beam region of the annular mirror and is reflected therefrom, and the transmit optical beam can proceed toward the dichroic beam splitter without impinging on the annular mirror.