Where have our VPHGs gone?

摘要

The new possibilities offered since few years by the use of Volume Phase Holographic Gratings (VPHG) in astronomy have not yet yielded a new generation of instrumentation. New larger telescopes await their light analyzing devices and the higher throughput, higher versatility and lower cost of VPHG still do not award their position. We seems to have reached a stability in gratings manufacturing but their use resides mainly in R&D sector. Our group in Italy does not walk too far off this road and proposes a series of non-conventional uses of VPHG aside of refurbishing of classical, existing instrumentation.