Versatile tool for accurate efficiency analysis of holographic materials and optical elements

Over the past 15 years, advancements in manufacturing technologies for holographic optical components such as filters and diffraction gratings have promoted significant improvement in optical instrumentation, particularly in throughput and wavelength selectivity. This implies the critical need for reliable and precise instruments for characterizing their optical properties. At INAF, we have facilities for the production of Volume Phase Holographic Gratings and in parallel, we’ve developed a versatile setup for the measurement of the diffraction efficiency as function of the incidence angle in the UV-SWIR band building a spatial map. The same setup can measure the transmittance and reflectance of mirrors, filters and glass windows of any material. The instrument can host samples up to 250 mm in diameter. A custom-made LabView software control all the parameters allowing for fully automatic measurements. Future plans entail expanding the capacity to accommodate 450 mm self-produced VPHGs in the new, cutting-edge laboratory under construction at INAF.