3-D measurements using conoscopy and application to ophthalmology

In this paper we present a novel method to measure 3-D quasi planar or quasi spherical reflective surfaces with submicron depth accuracy. Two implementations are presented: a scanning and a non-scanning system. The non-scanning device allows fast measurements and can be applied for eye-shape measurements. The paper is organized as follows: in the introductory section, we first demonstrate the principle of the conoscopic effect leading to the formation of the interferogram. The second and third sections explain respectively. the scanning and non-scanning methods based on the conoscopic effect. We present the experimental results from a simple measurement and show how they conform with theory.