Data needs for the newer optical materials

Despite all the research that has been conducted on the newer optical materials and the many engineering measurements that have been made on them, there still exist serious gaps in the data available. These are especially apparent at temperatures higher than ordinary ambient; at the lower temperatures, down almost to absolute zero, that are encountered by space instrumentation; and in the far-infrared region. Furthermore, there is no single source for all the data on all the available optical materials. The present paper describes this situation, largely as an incentive for physicists and engineers to make additional, badly needed measurements.