Methodology and design of fixtures for precision alignment of MTP/MPO connectors and MT ferrules in interferometric end-face measurements

A fixture configured for measuring multi-fiber connectors or ferrules with an interferometric microscopes, the fixture comprising:

• a base having first and second planar surfaces and configured to attach to an interferometric microscope with at least the second planar surface facing the interferometric microscope;
• a guide pin disposed on the base and extending approximately perpendicular to the first planar surface of the base and configured to fit into at least one guide hole of a female multi-fiber connector or ferrule to allow orientation of the female multi-fiber connector or ferrule with respect to the optical axis of the interferometric microscope;
• and
• first and second window openings in the first and second planar surfaces of the base and through the base, the first and second window openings respectively disposed on different sides of the guide pin, wherein the first and second window openings are sized to be approximately equal to one half the area of an end face of the female multi-fiber connector or ferrule that contacts the planar surface of the base when placed on the guide pin such that light from the interferometric microscope illuminates approximately one half of the end face of the female multi-fiber connector when placed on the guide pin for measurement of the female multi-fiber connector.