A new way of fabricating high-efficiency diffraction gratings for astronomical spectroscopy

Today, astronomers seek to observe the faintest and most distant objects possible. Extremely Large Telescopes (ELTs), with apertures in the order of several dozen meters, are the next generation facilities to do so. However, building larger telescopes is only one part of the equation. The other part is the capability of detecting the gathered photons in the most efficient way possible.