Thermal Expansion and Temperature Dependence of the Refractive Index in Gradient Refractive Index Glasses.
The thermal expansion and temperature dependence of the refractive index in gradient index glass have been investigated. These two thermal properties have been modeled as functions of local glass composition within the gradient index region. Additive relationships have been developed for gradient index glass from previous work done on homogeneous glass modeling. Computer programs have been written to calculate the expansion and change in refractive index due to thermal changes in the gradient index glass environment. A modified multiple Fabry-Perot interferometer was designed and built into an environmental temperature chamber to measure these thermal properties in gradient index glass in the range from 0-100 degrees Celcius. The interferometer operated under computer control to optically measure the differential expansion and change in refractive index profile in several samples of gradient index glass. The observed changes in thermal expansion and gradient index profile were also evaluated in terms of their effect on the imaging performance of a gradient index lens.
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- Physics: Optics