High-precision double-frequency interferometric measurement of the cornea shape

Vasyl V. Molebny; Ioannis G. Pallikaris; Leonidas P. Naoumidis; Eugene M. Smirnov; Leonid M. Ilchenko; Vadym O. Goncharov

doi:10.1117/12.257378

8 November 1996 High-precision double-frequency interferometric measurement of the cornea shape

Vasyl V. Molebny, Ioannis G. Pallikaris, Leonidas P. Naoumidis, Eugene M. Smirnov, Leonid M. Ilchenko, Vadym O. Goncharov

Author Affiliations +

Proceedings Volume 2965, ALT '96 International Symposium on Laser Methods for Biomedical Applications; (1996) https://doi.org/10.1117/12.257378
Event: ALT '96 International Symposium: Laser Methods for Biomedical Applications, 1996, Heraklion, Crete, Greece

Abstract

To measure the shape of the cornea and its declinations from the necessary values before and after PRK operation, s well as the shape of other spherical objects like artificial pupil, a technique was used of double-frequency dual-beam interferometry. The technique is based on determination of the optical path difference between two neighboring laser beams, reflected from the cornea or other surface under investigation. Knowing the distance between the beams on the investigated shape. The shape itself is reconstructed by along-line integration. To adjust the wavefront orientation of the laser beam to the spherical shape of the cornea or artificial pupil in the course of scanning, additional lens is involved. Signal-to-noise ratio is ameliorated excluding losses in the acousto-optic deflectors. Polarization selection is realized for choosing the signal needed for measurement. 2D image presentation is accompanied by convenient PC accessories, permitting precise cross-section measurements along selected directions. Sensitivity of the order of 10^-2 micrometers is achieved.

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Vasyl V. Molebny, Ioannis G. Pallikaris, Leonidas P. Naoumidis, Eugene M. Smirnov, Leonid M. Ilchenko, and Vadym O. Goncharov "High-precision double-frequency interferometric measurement of the cornea shape", Proc. SPIE 2965, ALT '96 International Symposium on Laser Methods for Biomedical Applications, (8 November 1996); https://doi.org/10.1117/12.257378

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