Chinese Optics Letters, 2016, 14 (7): 071202, Published Online: Aug. 3, 2018
Improved phase-shifting diffraction interferometer for microsphere topography measurements Download: 1074次
120.5050 Phase measurement 120.3180 Interferometry 120.6650 Surface measurements, figure 220.4830 Systems design 260.5430 Polarization
Abstract
In this study, an improved phase-shifting diffraction interferometer for measuring the surface topography of a microsphere is developed. A common diode-pumped solid state laser is used as the light source to facilitate apparatus realization, and a new polarized optical arrangement is designed to filter the bias light for phase-shifting control. A pinhole diffraction self-calibration method is proposed to eliminate systematic errors introduced by optical elements. The system has an adjustable signal contrast and is suitable for testing the surface with low reflectivity. Finally, a spherical ruby probe of a coordinate measuring machine is used as an example tested by the new phase-shifting diffraction interferometer system and the WYKO scanning white light interferometer for experimental comparison. The measured region presents consistent overall topography features, and the resulting peak-to-valley value of 84.43 nm and RMS value of 18.41 nm are achieved. The average roughness coincides with the manufacturer’s specification value.
Guodong Liu, Binghui Lu, Heyi Sun, Bingguo Liu, Fengdong Chen, Zhitao Zhuang. Improved phase-shifting diffraction interferometer for microsphere topography measurements[J]. Chinese Optics Letters, 2016, 14(7): 071202.