What are CGH ghosts and what can be done to minimize them?

CGH ghosts arise from light in diffraction orders that are different from the design diffraction order which make their way back into the interferometer.

Ghosts can show up as hotspots in data and typically look like dense bullseye-shaped fringes.

All efforts are made to eliminate or minimize the impact of ghosts during the CGH design phase.  This is done by adding tilt and spacing adjustments to the test geometry.

Learn more about AOM Metrology CGHs.