Novel wide field-of-view laser retroreflector for the space interferometry mission

A new type of laser retroreflector has been developed for JPL’s future Space Interferometry Mission. The retroreflector consists of an assembly of prisms to form multiple hollow cornercubes. This way the limited field of view (FOV) of about 60deg of a single corner can be overcome, to comply with the geometry of an optical truss. In addition, an innovative feature is that the retroreflector has common vertices, in order to define a single point optical fiducial necessary for point-to-point 3D laser metrology. The multiple cornercube provides better thermal stability and optical performance than spherical and hemispherical type retroreflectors. In manufacturing the prototype, the key technology of assembling prisms to the interferometric accuracy has been demonstrated. A non common vertex error of a few ~m has been achieved, Kevwords: Interferometry, retroreflector, cornercube, optical fiducial, laser metrology, optical truss 1