Toric surface curvature radius interferometric measurement method for esp. eye cornea

摘要

The method involves using two collimated coherent beams of light and two detection cameras detecting light at respective different frequencies. Spherical waves from the beams interfere with each other and are blended out from the illumination beam course e.g. a laser beam, across a polarisation beam divider (5). The resulting interference image is detected simultaneously at least two different optical wavelengths. The interference strip distance is determined with each of the two wavelengths. Also from these and the wavelength difference, the curvature radius in the plane of the illumination formed by the coherent is determined. The strip distances are determined three times at least following the alteration of the angle of the illumination plane relative to the main axes of the toric surface. The orientation of the main axes and the main curvature radii is determined from the strip distances.