Low-coherence interferometer for contact lens surface metrology

Kyle C. Heideman; John E. Greivenkamp

doi:10.1117/1.OE.55.3.034106

29 March 2016 Low-coherence interferometer for contact lens surface metrology

Kyle C. Heideman, John E. Greivenkamp

Author Affiliations +

Optical Engineering, Vol. 55, Issue 3, 034106 (March 2016). https://doi.org/10.1117/1.OE.55.3.034106

Abstract

Contact lens performance depends on a number of lens properties. Many metrology systems have been developed to measure different aspects of a contact lens, but none test the surface figure in reflection to subwavelength accuracy. Interferometric surface metrology of immersed contact lenses is complicated by the close proximity of the surfaces, low surface reflectivity, and instability of the lens. An interferometer to address these issues was developed and is described here. The accuracy of the system is verified by comparison of glass reference sample measurements against a calibrated commercial interferometer. The described interferometer can accurately reconstruct large surface departures from spherical with reverse raytracing. The system is shown to have residual errors better than 0.05% of the measured surface departure for high slope regions. Measurements made near null are accurate to λ/20. Spherical, toric, and bifocal soft contact lenses have been measured by this system and show characteristics of contact lenses not seen in transmission testing. The measurements were used to simulate a transmission map that matches an actual transmission test of the contact lens to λ/18.

Citation Download Citation

Kyle C. Heideman and John E. Greivenkamp "Low-coherence interferometer for contact lens surface metrology," Optical Engineering 55(3), 034106 (29 March 2016). https://doi.org/10.1117/1.OE.55.3.034106

Published: 29 March 2016

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available