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Proceedings Paper

Optical measurement of materials and lens assemblies at specific or varied temperatures
Author(s): John J. Nemechek
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Paper Abstract

Optical materials and lens assemblies are specified for use at various operating temperatures. Ophthalmic lenses such as intra-ocular (IOLs), rigid gas permeable (RGP), and soft contact lenses must be verified at a single well-controlled temperature to ensure correct performance. In comparison, lens assemblies for UAVs (unmanned aerial vehicles) and other “outdoor” applications demand performance over a substantial range of temperatures. Both applications demand the ability to integrate temperature monitoring or control with optical measuring instruments. A common practice is to thermally soak the material or lens assembly and then attempt measurement before the object under evaluation returns to ambient room temperature. We are reporting on the utilization of a NIST-traceable temperature device combined with wavefront sensing technology for faster integrated measurement capability. The temperature sensor is currently capable of 0.01 and 0.1 degree C resolution and accuracy; respectively for an operating range of 0 to 100 degrees C. Efforts are underway to extend the temperature measurement range down to -30 C. The wavefront measurement device is a Shack- Hartmann sensor (SHS) operating at 5 to 15 Hz with simultaneous gauging of temperature. The SHS can be operated with a choice of wavelengths from 400 to 1,000 nm. It also supports both single and double-pass configurations. The single-pass arrangement was chosen for these experiments due to the simpler, more compact set-up. The dynamic range of the wavefront sensor is first utilized to evaluate the temperature chamber. Results are then presented for two lens assemblies intended for commercial UAVs.

Paper Details

Date Published: 12 October 2015
PDF: 5 pages
Proc. SPIE 9633, Optifab 2015, 96331S (12 October 2015); doi: 10.1117/12.2197598
Show Author Affiliations
John J. Nemechek, Metrology Concepts LLC (United States)


Published in SPIE Proceedings Vol. 9633:
Optifab 2015
Julie L. Bentley; Sebastian Stoebenau, Editor(s)

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