As most schoolchildren know, the stars don’t really come out in the dark. They are always in our skies, and shine just as brightly at noon as they do at midnight. Our inability to see them at noon is because they are obscured by the light of our sun. Were we somehow able to filter out those rays of sunshine, we would be able to see the stars just as plainly in the day as we do before the dawn.

Astronomers searching for “extrasolar” planets -- planets circling stars millions of miles from our sun -- face a similar challenge: The feeble rays of light reflected from those planets are all too often obscured by a halo of light that surrounds the stars that they orbit, hiding them from the view of even our most powerful telescopes.

Fortunately, an innovative, state-of-the-art optic from II-VI INFRARED is helping astronomers shed light on extrasolar planets by filtering out the halo of light from their suns. Known as an Apodized Phase Plate, or APP, the optic is one of many specialized, “non-rotationally symmetric” optics made in II-VI INFRARED’s Diamond Turning production facility in Saxonburg, Pennsylvania.

The APP, like II-VI INFRARED’s industry-leading high-power CO2 laser lenses, is made of optical-quality zinc selenide (ZnSe). Small amplitude sinusoidal ripples and additional ripples are diamond-turned into the optic, using II-VI INFRARED’s precision fast- and slow-tool servos. This creates a finished product that suppresses some of the distant starlight, increasing the chances for astronomers to see extrasolar planets that would otherwise be obscured.

Currently, APPs are being tested at the Center for Astronomical Adaptive Optics at the University of Arizona’s Steward Observatory. A PDF of their initial findings is available for download. (Click here to download the PDF.) Additional information regarding II-VI INFRARED’s non-rotationally symmetric optics is available on this Web site. For those interested in the design pattern described within the PDF, contact Johanan Codona (jcodona@as.arizona.edu).