A Fizeau interferometer without beam splitter is constructed. Single-mode optical fiber is used as a spherical wave source and the face of fiber end is polished and coated to be a reflecting surface. The waves from reference surface and measurement surface are converged into a single point and the superposition of the two waves produces an interferogram as a result of phase difference. The reflecting surface is angled so that this interference fringe can be detected by CCD camera. Beam splitter in front of a spherical wave source could distort the wave front and that is one of the component error sources. With the proposed configuration there is no need to place beam splitter in the system. Improvement of phase measuring accuracy is evaluated quantitatively by comparing the result of this setup with that of a conventional Fizeau interferometer. Wave front of the angled end-face optical fiber source is also measured to verify its sphericity by PS/PDI(Phase Shifting/Point Diffraction Interferometer). The principle of this technique is presented and the experimental results and its applications are discussed.
