Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Exposure Study on the Aging of PTFE and Ceramic Diffusers



Benjamin K. Tsai, Catherine C. Cooksey, David W. Allen, Christopher C. White, Walter E. Byrd, Deborah S. Jacobs


This paper describes efforts to quantify the effects of aging in the ultraviolet (UV) on polytetrafluoroethylene (PTFE) and ceramic samples. Long term UV aging may significantly alter the reflectance factor and cause an error in the calibration of reflectance standards. A large integrating sphere was used to irradiate the samples for an extended period of time equivalent to about 4.3 solar units. Samples were qualified and measured for reflectance, bidirectional reflectance distribution function (BRDF), and fluorescence data, before and after the year-long measurements, as well as in between the 3-month aging periods. This study revealed significant differences between the aging behavior of ceramic and PTFE samples.
Applied Optics


Aging, BRDF, Ceramics, Fluorescence, Humidity, PTFE, Reflectance, UV


Tsai, B. , Cooksey, C. , Allen, D. , White, C. , Byrd, W. and Jacobs, D. (2019), Exposure Study on the Aging of PTFE and Ceramic Diffusers, Applied Optics, [online], (Accessed July 22, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created February 6, 2019, Updated June 17, 2019