Optical Fabrication and Testing
Apodized Apertures and Graded-Reflectivity Mirrors for High-Power Lasers
Several types of apodized (soft) apertures based on color centers in rare-earth-doped fluorite crystals with super-Gaussian transmission profiles and high laser damage thresholds were developed and tested in both high-power laser systems to suppress Fresnel diffraction ripples and in laser resonator for brightness enhancement. Developed multilayer graded reflectivity mirrors with spatially profiled dielectric layers increased brightness of a high-power industrial solid-state laser. Spatially profiled dielectric layers were also used in the frustrated total internal reflection apodizers.
Gradient Index Materials
Gradient-index (GRIN) materials have an index of refraction that varies as a function of position. Research in our group focuses on glass and plastic GRIN lenses to be used in optical systems. These elements are useful to a lens designer since they provide additional degrees of freedom, and thus can improve system performance. Research topics currently pursued range from the beginning of the process (fabricating the GRIN materials) to end applications (designing and tolerancing the optical systems).
Optical Metrology and System Alignment by Phase Retrieval
The Phase Retrieval and Imaging Science Group conducts research into obtaining improved performance in imaging systems and measuring wavefronts by computational means. Current projects include phase retrieval as means for precision optical metrology for aspheric surfaces and for alignment of optical systems.