Manufacturing of a fiber optic Young's double pinhole interferometer for use as a 3-D profilometer

The method used to manufature a Young's double pinhole interferometer is di scussed. This interferometer is destined to be used in a surface profilomet er using two wavelengths so that the zero order fringe can be determined. H ence stringent requirements are placed on the absolute length difference be tween the two output fibers of a single mode coupler. These requirements ar e discussed along with the manufacturing process. The interferometer is sho wn along with measurements showing a length difference on the order of 6 mu m. (C) 2000 Optical Society of America.