Abstract

We discuss the technology requirements for the POINTS optical interferometric instrument. Angular resolution of 5 × 10⁻⁶ arcsec (25 prad) by using an interferometer with a 2-m baseline requires internal distance metrology at the few picometer level and precise starlight fringe splitting. We have shown long term stability of two picometers in measurements on a Michelson-type distance gauge; we will soon test a design for point- to-point distance measurements. Full-aperture metrology of the starlight path has shown promising results with the first prototype zone-plate mirror, which diffracts part of the incident light to an auxiliary focus. Other applicable technological areas include broadband mirrors and beam splitters with stable phase shift and polarization properties, high-efficiency broadband detector arrays, thermally stable glasses and structural materials, integrated optics, a stable and robust laser source in the near infrared, supersmooth surfaces, and precision glass assemblies.

© 1992 Optical Society of America