Proceedings Article | 18 November 2019
Proc. SPIE. 11189, Optical Metrology and Inspection for Industrial Applications VI
KEYWORDS: Photovoltaics, Polishing, Interferometers, Sensors, Optical testing, Aspheric optics, Aspheric lenses, Infrared radiation, Optics manufacturing, Surface finishing
Aiming at the disadvantage of small diameter, low efficiency, poor accuracy and can only measure sub-aperture of traditional contact surface shape measurement method to detect grinding optics surface, this paper uses non-contact laser displacement sensor, and proposes an in-situ measurement method to measure full-aperture surface of grinding optics, it has the characteristics of high measurement efficiency, high accuracy, large measurement aperture and the ability to measure full-aperture surface. This method is in-situ measurement, so it can measure full-aperture surface of optics with arbitrary aperture and shape after rough grinding, semi-precision grinding and fine grinding. Orthogonal co-directional grating measurement path can effectively avoid the influence of machine backlash. Therefore, the optics can be directly compensated according to the results of surface measurement, so that the surface of optics can meet the requirements. After the measurement is completed, a set of orthogonal measurement data are obtained, and the invalid data are manually clipped. Linear interpolation, nearest neighbor interpolation and cubic spline interpolation are used to interpolate the clipped data, and the orthogonal data are superimposed to obtain the final shape. The validity of this method is verified by the sub-aperture surface detection method, experiments show that the optimal surface measurement results can be obtained by cubic interpolation for both planar and aspheric optics. Using this method to compensate the grinding of 530mm×530mm 2-D off-axis aspheric optics, the full-aperture surface shape accuracy PV is better than 3.5μm.
