Paper
14 February 2018 Non-destructive geometric and refractive index characterization of single and multi-element lenses using optical coherence tomography
Author Affiliations +
Abstract
Design of optical imaging systems requires careful balancing of lens aberrations to optimize the point-spread function (PSF) and minimize field distortions. Aberrations and distortions are a result of both lens geometry and glass material. While most lens manufacturers provide optical models to facilitate system-level simulation, these models are often not reflective of true system performance because of manufacturing tolerances. Optical design can be further confounded when achromatic or proprietary lenses are employed. Achromats are ubiquitous in systems that utilize broadband sources due to their superior performance in balancing chromatic aberrations. Similarly, proprietary lenses may be custom-designed for optimal performance, but lens models are generally not available. Optical coherence tomography (OCT) provides non-contact, depth-resolved imaging with high axial resolution and sensitivity. OCT has been previously used to measure the refractive index of unknown materials. In a homogenous sample, the group refractive index is obtained as the ratio between the measured optical and geometric thicknesses of the sample. In heterogenous samples, a method called focus-tracking (FT) quantifies the effect of focal shift introduced by the sample. This enables simultaneous measurement of the thickness and refractive index of intermediate sample layers. Here, we extend the mathematical framework of FT to spherical surfaces, and describe a method based on OCT and FT for full characterization of lens geometry and refractive index. Finally, we validate our characterization method on commercially available singlet and doublet lenses.
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mohamed T. El-Haddad and Yuankai K. Tao "Non-destructive geometric and refractive index characterization of single and multi-element lenses using optical coherence tomography", Proc. SPIE 10483, Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXII, 104832O (14 February 2018); https://doi.org/10.1117/12.2292133
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Refractive index

Optical coherence tomography

Fourier transforms

Optics manufacturing

Optical design

Systems modeling

Glasses

RELATED CONTENT

Specifying Optical Materials
Proceedings of SPIE (January 16 1989)
Invited paper Status and future of polymeric materials in...
Proceedings of SPIE (January 01 1991)
Dispersion of GRADIUM glasses from 350 to 2500 nm
Proceedings of SPIE (September 25 1997)

Back to Top