Halftoning for High-contrast Imaging: Developments for the SPHERE and EPICS Instruments
Résumé
Controlling the amplitude of light is crucial for many scientific applications, such as in imaging systems, astronomical instruments or laser physics. We provide a brief overview of recent R&D activities at ESO using halftoning, the process of presenting a continuous image through use of dots. Customised filters with spatially varying transmission are produced using a binary array of metal pixels that offers excellent control of the local transmission. Applications to the production of an apodiser for the VLT SPHERE instrument and a mask for E-ELT EPICS are presented.