Astronomical mirrors and
Large-size optics manufacturing

see also:     < International Projects completed by Lytkarino Optical Glass Factory, JSC for finished optical mirrors >
see also:     < International Projects completed by Lytkarino Optical Glass Factory, JSC for substrate blanks fabrication >

0.015

(=0.6328m)

Among performed components there are light-weighted some (weight reduction up to 80%) and thin optical parts as well axis and off-axis having random shape of external perimeter.

 

The most significant recently fulfilled project is the contract for supply of 98 hexagonal blanks made of Astrositall® with dimensions 1019õ55mm intended for segmented Primary mirror of Telescope SALT (www.salt.ac.za). For successful and accurate fulfillment of this project the new generation interference dilatometers were designed and performed. They are ensuring CTE measurement of tolerances in range not more than 5õ10-9degrees C-1. And CTE homogeneity measured in 18 samples taken from different places of a blank did not extend a deviation value 15õ10-9degrees Ñ-1. photos ...

 

In 2001 the contract for manufacturing of the unique set of optics intended for VLT Telescope (VLT Survey Telescope, Osservatorio Astronomico di Capodimonte Napoli, http://oacosf.na.astro.it/vst/). The Primary mirror has diameter 2650mm and the Secondary one - 938mm having a-sphericity aprox. 100 microns at each the mirrors. The primary mirror VST is an adaptive one and manufactured in shape of meniscus with thickness 140mm, and having thickness to diameter ratio as 1:19. Nowadays LZOS company is producing the second similar mirror. more details ...

 

primary mirror figuring

1.2m optical system for Telescope STELLA, Astronomical institute of Potsdam (www.aip.de/stella/) is manufactured under the contract with Carl Zeiss for firm Halfmann (www.halfmann-teleskoptechnik.com/htm/telescopes.htm). The mirrors are made of ZERODUR® Schott company. The primaru mirror 1220mm, the Secondary mirror 455mm, the tertiary mirror 350x250mm. Wave-front RMS after subtraction of constant ratios, disfocusing tilts and de-centering coma is about 0.03 (=632.8nm).

 

Within period 1997-2001 years under Carl Zeiss contract our company manufactured 4 Primary mirrors with hyperbolic surfaces having 2050mm and 2 Secondary mirrors having diameters 645mm of Astrositall® material intended for TTL Project (Telescope Technologies Limited, Great Britain) (www.ngat.com/fulman1.htm). Asphericity of the nearest sphere on the Primary mirror is about 20 microns; on the second one is about 12 microns. RMS Wave-front of the Primary mirrors is aprox. 0.03 (=0.6328 microns). The similar quality was obtained on the secondary mirrors. Completely computer-controlled telescopes are built in Canaries islands (Liverpool Telescope, telescope.livjm.ac.uk), in India (iucaa.ernet.in), Hawaiian Islands and Australia (Faulkes Telescopes www.faulkes-telescope.com).

 

LZOS Company as a sub-contractor of Carl Zeiss, Jena (www.zeiss.de) manufactured the set of optics ARISTARCHOS of NOA Telescope (Astronomical Institute - National Observatory of Athens, Greece www.noa.gr, www.astro.noa.gr/ASC_2.3m/ngt_main.htm) that is composed of The Primary mirror diameter 2280mm, the Secondary mirror diameter 753mm and tree-lenses field corrector. A-sphericity of the Primary mirror is aprox. 40 microns, the Secondary one - 26 microns. The mirrors system: Primary and Secondary has EE 80% in the spot less than 0.3".

 

In 2003 year our company completed fabrication of optics for two Schmidt systems with spherical mirror diameter aprox. 600mm (radius of curvature is 1294mm) and Schmidt plate with diameter 424mm. Schmidt plate has a-sphericity value about 84 microns of the nearest sphere with 19800mm. The spherical mirror and compensating elements are produced separately and final testing, Schmidt plate fabrication was carried out in optical lay-out with a large-size objective. RMS (WFE) at wavelength =633nm is less than 0.05.

 

The contract with Carl Zeiss (Germany) and AMOS (Belgium) for figuring and testing of the Tertiary flat mirror having elliptical shape and made ZERODUR® substrate for the Project GRANTECAN, Spain (www.gtc.iac.es/home.html). The Mirror dimensions 1520x1073mm. With purpose to test the flat surface of this mirror the special vertical test-bench is designed and mounted that allows to conduct measurement under the mirror in Ritchey-Common lay-out at two angles of main beam incidence. The angular position of the interferometer optical axis to horizontal plane equals to 60o.

In 2003 year the optical collimator with 30m focal length was produced with following parameters: flat 1250mm, parabola 1100mm, hyperbola 188mm, flat 135mm.

 

convex hyperbolic mirrors testing measurements in two Hindle spheres

Within 1999-2002 years period LZOS Company as a sub-contractor of Carl Zeiss (Germany) manufactured two Secondary mirrors with diameters 645 mm (F/2.5) for TTL Project (Telescope Technologies Limited, Great Britain). Asphericity is about 12 microns of the nearest matching sphere. RMS of Surface is about 9nm. The mirrors system: The Primary and The Secondary have EE 80% in spot less than 0.2". The secondary mirror is manufactured and figured with diameter 753mm (F/2) for NOA (Astronomical Institute - National Observatory of Athens, Greece). Asphericity is about 26 microns. RMS of surface is aprox. 12nm. The telescope viewing field is about 1.04o. The mirrors system: Primary and Secondary has EE 80% in spot less than 0.3". more details ...

see also:     < major current projects >