M2 secondary mirror manufacturing for VISTA project

This paper discusses the technology involved in automatically shaping the surfaces of primary telescope mirrors up to 4 m in diameter and with asphericity up to 1000 μm. It describes methods for monitoring the automatic grinding of surfaces by IR interferometry, automatic polishing and finishing of surfaces with wave-front correctors, and a method of simultaneously monitoring various designs of correctors to achieve and confirm the required parameters of an aspheric with the same surface. A description is given of the features of the fabricated auxiliary equipment (membranepneumatic actuator for unloading the mirror, load-bearing equipment, containers, and devices for cementing interface elements).• Energy concentration 80% on the axis of the system of two mirrors in a circle of confusion with diameter 0.15 00 after 207

Section: Shaping and Finishing The Surfaces Of Optical Itemsmentioning

confidence: 99%

Section: Shaping and Finishing The Surfaces Of Optical Itemsmentioning

confidence: 99%

Technological features of the fabrication of the primary mirrors of telescopes

Semenov¹,

Abdulkadyrov²,

Belousov³

et al. 2013

“…The most significant projects in the production of mirror blanks are the SALT (Southern African Large Telescope) project, 1,2 the LAMOST (Large Sky Area Multi-Object Spectroscopic Telescope) project, 1,2 the VST (VLT Survey Telescope) mirror, 3,4 the VISTA (Visible and Infrared Survey Telescope for Astronomy) secondary mirror, 5 the hexahedra for mirror prototypes for superlarge telescopes E-ELT (European Extremely Large Telescope), TMT (Thirty-Meter Telescope), etc.…”

Section: Introductionmentioning

confidence: 99%

Technology for fabricating large, high-accuracy, lightened aspheric mirrors with high stability of the surface shape

Abdulkadyrov¹,

Dobrikov²,

Patrikeev³

et al. 2014

“…When astronomical optical items are being shaped, 1,2 lens-type and mirror-lens-type wave-front (WF) correctors 2,3 are used at the Lytkarino Optical Glass Factory (OAO LZOS) to test the aspheric surfaces. As an alternative test method, a diffraction optical element (DOE) 4 -a DOE corrector or computer-generated hologram (CGH)-is used as a holographic corrector.…”

Section: Introductionmentioning

confidence: 99%

Interference methods of testing the surface figure of large aspheric items, based on lens-type and holographic wave-front correctors

Semenov¹,

Abdulkadyrov²,

Patrikeev³

et al. 2013

This paper discusses the features of methods of testing aspheric primary mirrors of telescopes with lens-based, mirror-lens-based, and holographic correctors. Methods are described for simultaneously testing the same surface of an optical item with different correctors to achieve and confirm the required parameters of the aspheric (vertex radius and conic constant). Results are given for testing the correctors with a holographic mirror simulator to verify the fabrication accuracy of the correctors themselves and, if necessary, of the wave-front correction of the lens correctors.