Correction of atmospheric distortion with an image-sharpening telescope*

Abstract

We have built and tested a 30 × 5 cm aperture telescope which used six movable mirrors to compensate for atmospherically induced phase distortion. A feedback system adjusts the mirrors in real time to maximize the intensity of light passing through a narrow slit in the image plane. We have achieved essentially diffraction-limited performance when imaging both laser and white-light objects through 250 m of turbulent atmosphere. The behavior of our telescope was accurately predicted by computer simulations. The system has yet to achieve its full potential, but has already operated successfully for objects as dim as 5th magnitude.