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Materion to Provide Coatings for World’s Largest Astronomical Filters

Filters to Enable Images for LSST Digital Camera 

LSST Facility-Photo Mason Productions/LSST CorpMaterion Precision Optics is set to begin the first phase of manufacturing the coatings for six of the world’s largest precision astronomical filters to date for the new Large Synoptic Survey Telescope (LSST).   The curved filters, 80 cm in diameter and weighing between 15-30 kilograms, will be installed in the telescope’s (3.2 gigapixel) digital camera for a 10-year period to survey and map tens of billions of stars and galaxies.

(A simulated night sky provides a background for the LSST facilities building on Cerro Pachón. The LSST will carry out a ten-year imaging survey in six broad optical bands over the main survey area. Credit: Todd Mason, Mason Productions Inc./LSST Corp.)

“Only a few years ago, a large filter would have been around 10 cm in diameter. We have repeatedly scaled up to meet the astronomy community's increasing requirement for larger filters,” said Tom Mooney, large optics product manager at Materion.  “The LSST filters will be the largest we have built and our large optics facility in Westford, MA is suited for the task since it was designed with such filters in mind."

The coating design and process development phase of the large astronomical filters  will be conducted in Materion’s Large Optics Facility Class 1000 clean-room, which is capable of coating optics up to 1.4 meters in diameter.  The filters will contain a surface coating uniformity of well under one percent and cover spectral wavelengths from ultraviolet to near infrared.  The facility will also allow for spectral performance testing of the filters using Materion’s newly developed metrology instrument. 

LSST Telescope_Photo Mason Productions/LSST CorpMaterion’s astronomical filters for the Lawrence Livermore National Laboratory will make it possible for the LSST to document a section of the sky every 34 seconds, amounting to more than 2,000 panoramic images each night off the El Peñón mountain peaks in northern Chile.  In total, the telescope is expected to produce 5 million images yielding 0.5 exabytes of raw data, capturing sharp images of objects 2.5 billion times fainter than visible to the human eye. 

With over 45 years of experience since its start as Barr Associates Inc., Materion Precision Optics has been at the forefront of producing large astronomical filters for the space and astronomy industry.  Recent work in the Large Optics Facility has included the production of large filters for Subaru Hyper-Suprime Cam (HSC), 60 cm diameter; DECam, 62 cm diameter; Zwicky Transient Facility (ZTF), 49 x 45 cm; Canada France Hawaii Telescope (CFHT) MegaCam upgrade, 30 cm x 35 cm; and many others.

For more information about Materion’s astronomical filters and related capabilities, contact Dave Harrison, Business Development Manager of Precision Coatings.