Interferometers

Claim 1

AN INTERFEROMETER SYSTEM COMPRISING A BEAMSPLITTER ASSEMBLY FOR SPLITTING AN INCIDENT BEAM INTO A FIRST BEAM AND A SECOND BEAM THAT IS SUBSTANTIALLY PARALLEL TO SAID FIRST BEAM, SAID BEAMSPLITTER ASSEMBLY COMPRISING A BEAMSPLITTER EMBEDDED IN AN INTERFACE OF A SUBSTANTIALLY PARALLEL PLATE WHICH INTERFACE IS SUBSTANTIALLY PARALLEL TO A FIRST FACE OF SAID PARALLEL PLATE, A FIRST MIRROR DISPOSED OVER A PORTION OF SAID FIRST FACE, SAID BEAMSPLITTER TRANSMITTING SAID SECOND BEAM TO A SECOND FACE OF SAID PARALLEL PLATE WHENCE IT EMERGES, AND REFLECTING SAID FIRST BEAM TO SAID FIRST MIRROR WHICH REFLECTS IT TO SAID SECOND FACE OF SAID PARALLEL PLATE WHENCE IT EMERGES SUBSTANTIALLY PARALLEL TO SAID EMERGENT SECOND BEAM, A BIFACIAL REFLECTOR POSITIONED TO RECEIVE ON ONE OF ITS FACES AT SUBSTANTIALLY NORMAL INCIDENCE SAID EMERGENT FIRST BEAM, AND A RETROREFLECTOR POSITIONED TO RECEIVE SAID EMERGENT SECOND BEAM AND TO RETROREFLECT IT TO THE SECOND FACE OF THE BIFACIAL REFLECTOR AT SUBSTANTIALLY NORMAL INCIDENCE.