Ion-plasma etched nano-structured surfaces for high performance transmissive and diffractive elements in imaging/spectroscopic instruments for astronomy

Astronomy relies on detecting light from faint and distant objects in the Universe. To do this all light gathered by a telescope needs to be measured with highly efficient instruments that minimize losses of the light collected by the primary mirror. The investigators will build a new kind of diffraction grating and reflection-suppressing (anti-glare) optical lenses.

The team will etch nanometer-scale structures by bombarding the glass surfaces with charged ions in a controlled way. This method has been shown to greatly improve the light-transmission efficiency of these optical devices. In combination, gratings and anti-glare lenses will increase the efficiency of current and future observing instruments.

This program integrates and provides training opportunities for students in astronomy, instrument science, optical physics, and material engineering topics. There are potential applications of such devices in a broad range of electro-optical components and systems in other disciplines.

This research project aims to advance a range of photonic and instrumentation tools that are crucial for astronomical spectroscopic research. This includes the introduction of highly deterministic reactive ion etching fabrication technologies for high aspect ratio, compact line-density, high-dispersion astronomical surface relief gratings, as well as, randomly textured nanoscale anti-reflective surface structures, and their combined use to push diffraction and transmission efficiency to theoretical limits.

These gains will not only significantly enhance the capabilities of existing telescope and facilities, but also demonstrate the fabrication technology for diffraction gratings and transmissive optical elements needed in the next generation of astronomical instruments. When combined with Extremely Large Telescopes and their Adaptive Optics systems, these advances will make a significant improvement in total delivered throughput for a broad range of astronomical low/medium/high resolution spectroscopic instruments.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.