Optical system spectral transmission measurements in the visible and infrared

A commercial system designed for measuring detector spectral response was modified for automated testing of optical systems and subassemblies. The modified system provides test capability for large and complicated optics that are not supported by commercially available transmission test systems that test only witness samples or small optical assemblies. The modifications to the commercial hardware and software are described. Illustrations are given for single- and double-pass measurements of various optical systems. The performance capabilities of the new system are described along with methods used to validate the results. The usefulness of the new system is demonstrated by showing how systematic measurements on a complicated infrared imaging lens system were used to identify specific corrective actions. Measurements at the system and subsystem levels provide three unique optical system diagnostic capabilities: measurement of degradation due to time and environmental effects; system-, subsystem-, and component-level troubleshooting; and improved measurement accuracy by preventing error accumulation for multiple-element optical assemblies