The High Efficiency and Resolution Multi Element Spectrograph (HERMES) for the Australian Astronomical
Observatory (AAO) uses four large aperture, high angle of incidence volume phase holographic gratings (VPHG) for
high resolution ‘Galactic archaeology’ spectroscopy. The large clear aperture, the high diffraction efficiency, the line
frequency homogeneity, and mosaic alignment made manufacturing and testing challenging. We developed new
metrology systems at the AAO to verify the performance of these VPH gratings.
The measured diffraction efficiencies and line frequency of the VPH gratings received so far meet the vendor’s provided
data. The wavefront quality for the Blue VPH grating is good but the Green and Red VPH gratings need to be post
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jessica R. Zheng ; Luke Gers and Jeroen Heijmans
Metrology measurements for large-aperture VPH gratings
", Proc. SPIE 8838, Optical Manufacturing and Testing X, 88380G (September 7, 2013); doi:10.1117/12.2024493; http://dx.doi.org/10.1117/12.2024493