Characterizing and reporting effects of refractive index homogeneity structure to lens assembly performance

Historically, refractive index homogeneity has been specified by a normalized Peak-to-Valley. PV specifications carry risk for both manufacturer and customer as material with acceptable optical performance can fail, and material that is accepted is not well characterized for precision optics. Building on alternatives to PV proposed in the past, suggestions are given to specify refractive index homogeneity that are both practical and instrument agnostic. In this paper, we analyze a large sample of Corning Optical-Grade Calcium Fluoride to determine which refractive index homogeneity features could affect optical performance in a precision lens assembly. We suggest a new reporting method for refractive index homogeneity that more accurately characterizes the materials optical performance.