Dual-phase-shift spherical Fizeau interferometer for reduction of noise due to internally scattered light
| Autor: | Yasunari Nagaike, Kenichi Hibino, Toshiki Kumagai |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
Fizeau interferometer business.industry General Engineering Phase (waves) 02 engineering and technology 021001 nanoscience & nanotechnology Interference (wave propagation) 01 natural sciences Noise (electronics) Atomic and Molecular Physics and Optics Light scattering 010309 optics Optics 0103 physical sciences Reference surface Astronomical interferometer 0210 nano-technology business Phase modulation |
| Zdroj: | Optical Engineering. 56:034102 |
| ISSN: | 0091-3286 |
| DOI: | 10.1117/1.oe.56.3.034102 |
| Popis: | Internally scattered light in a Fizeau interferometer is generated from dust, defects, imperfect coating of the optical components, and multiple reflections inside the collimator lens. It produces additional noise fringes in the observed interference image and degrades the repeatability of the phase measurement. A method to reduce the phase measurement error is proposed, in which the test surface is mechanically translated between each phase measurement in addition to an ordinary phase shift of the reference surface. It is shown that a linear combination of several measured phases at different test surface positions can reduce the phase errors caused by the scattered light. The combination can also compensate for the nonuniformity of the phase shift that occurs in spherical tests. A symmetric sampling of the phase measurements can cancel the additional primary spherical aberrations that occur when the test surface is out of the null position of the confocal configuration. |
| Databáze: | OpenAIRE |
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