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Dream specializes in the design, engineering and in-house production of bubble-free lightweight mirrors. All mirrors are cast in-house in one of Dream's furnaces. The CTE of Dream's lightweight mirrors is 3x10-6/°K and is cast from Schott's Borofloat, a borosilicate glass.


Dream does not fuse, frit bond or use other such processes where individual glass components are cut and then assembled. These methods often make it extremely difficult, if not impossible, to vary specific rib thicknesses, create sub ribs, tapered ribs, etc. In short our cast method gives us far more design freedom and therefore far greater optimization than other methods.

All of Dream's mirrors are cast (melted) to produce a single, continuous mirror that does not suffer from potential bonding issues the other processes can and historically do experience. Dream mirrors don't have to "act" like one piece of glass because they ARE one piece of glass. They won't come apart today, tomorrow or 50 years from now.

They are not pocket-milled from a solid mirror blank either. Pocket-milling is limited in its design freedoms on rib types, depths, shapes, radii in corners, etc. Pocket-milling is typically 6-10x more expensive than Dream's technology.

Dream can create designs that are far more optimized than other processes allow. Dream started optimizing lightweight mirrors back in 2003. No other company in the world has our accumulated experience; design & engineering, casting & annealing, as well as using & testing them firsthand in Dream's finished telescopes. We bring an extensive knowledge base due to nearly 15 years of engineering & experience working with lightweight mirrors, as well as dedicated carbon fiber mirror mounts and full carbon fiber instruments. In this way we have closed the design and engineering loop because we do not simply produce lightweight mirror blanks, we process them (generation, grinding and polishing) and use them in full instruments.

This broader-based, real-world (empirical) knowledge, coupled with vertical integration of all tasks related to processing of the mirrors, allows Dream to maximize the mirror's design & features in every way. We feed what we learn back into the designs and have been since 2003. Dream is creating mirrors that are not just light, stiff and with a much shorter thermal time constant but functional and optimized to a degree never seen before. Ever.


"We shall look back and see how inefficient, how primitive it was to work with thick, solid mirrors, obsolete mirror-curves, ..."
- George Willis Ritchey 1928
From the book "Mirror Mirror" by Mark Pendergrast

 

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