Hubble Optics Lightweight Sandwich Mirror

We have developed a revolutionary lightweight sandwich mirror, that is a
cost effective and superior alternative to other lightweight and solid
mirrors available on the market.

Our sandwich mirrors have been used by NASA, US army, Princeton
University, California State Polytechnic University, and numerous other
organizations and individuals around the world.  The Hubble sandwich
mirrors are designed and built in a similar style to the Hubble Space
Telescope, the most advanced telescope ever built.

Currently, our lightweight sandwich mirrors are available from 8” to 24" in
diameter. Please contact us for larger mirrors.
After years of research, ASTS concluded that "thinner substrates
dramatically reduce the thermal time lag", Technical Note #0028 by Nathan
Dalrymple.  For any mirror, cross sectional thickness of the glass is the
primary factor in determining the thermal time temperatures during
observing or imaging, your full thickness mirror may never reach equilibrium,
and never reach its full optical potential.  This is one of the major reasons
why our lightweight-sandwich mirror has superior optical performance in real
world situations, even without an active cooling system. (Active cooling
systems, such as fans, introduce their own serious problems, such as micro
vibration, which can seriously degrade the image quality if not done
correctly.)  Our mirrors reach equilibrium extremely fast, and without aid.

So, with our lightweight-sandwich mirror, what is measured in the laboratory is observed
in the field.

Hubble Optics Lightweight Sandwich Key Features:
  • Thermal and Structural optimized open core, and dynamically stable
    closed back  design
  • Rapid Thermal Response: cools down about 10  times faster for
    mirrors up to 24", and about 20 times faster for mirrors between 25"
    -36",f than a solid mirror of equal thickness.
  • Outperforms both conventional solid and closed cell lightweight
    mirrors in term of image quality in the real world observation
  • Simple Flotation Mounting
  • Lighter than the solid mirrors (with weight saving about 20% for
    mirrors up to 20", and  about 40% for mirror larger than 20"
    comparing with the solid mirrors of equal thickness)
  • Cost competitive and unprecedented price/performance ratio

The Hubble Optics Lightweight Sandwich Mirror Price:

OD                     Thickness (mm)         Price (Plate glass)      Price( Pyrex )
12.0" (F/5)        ~49                                   $850                                 $1,300
14.0" (F/5)        ~49                                 $1,200                                $1,850
16.0" (F/5)        ~53                                 $1,650                                $2,550
18.0" (F/4.5)     ~53                                 $2,100                                $3,200
20.0" (F/4.2)     ~53                                 $3,050                                $4,400
24.0" (F/4.2)     ~65                                 $5,950                                $8,950
25.0"-40"                                            Contact us

Strehl Ratio >= 0.975

For faster mirrors, there is 15% surcharge for each 1/2 stop of the speed.

The above prices include the standard Al + SiO/SiO2 overcoating.

The 92% Semi-enhacned, 96% Enhanced Aluminum and 97% Protected
Silver  coatings are available with additional charges:

               Semi-Enhanced     Enhanced Aluminum     Protected Silver
8"                                 $90                            $290                             $365
10"                             $100                            $290                             $365
12.0"                          $110                            $295                             $385
12.5"                          $115                            $315                             $410
14.0"                          $125                            $340                             $435
16.0"                          $180                            $360                             $455
18.0"                          $220                            $380                             $515
20.0"                          $230                            $400                             $575

We do NOT recommend the Enhanced Aluminium and Protected Silver
coating for the primary mirrors.
The main problem is not the aberrations due to deformation, but the
layer of warm air in front of the primary mirror. This layer of warm air is
the main cause of the image distortion called "mirror seeing", which is
caused by the non-uniform index of diffraction in the cooler air over the
warm mirror surface. No mirror, regardless of the type of glass used,
will perform adequately until the mirror is close to the temperature of
the ambient air.  This occurs when the temperature difference between
glass and air is less than one degree centigrade (°C), and best
performance is achieved when this difference is less than 0.2 °C.
Therefore, the goal is to bring the temperature of the mirror to within 0.2 °C
of the ambient air temperature as quickly as possible.  This will greatly
reduce image distortion due to mirror seeing.  This is why all large
professional mirrors, regardless of the type of glass used, employ
complicated cooling systems to cool the primary mirror.  For example, the
Advanced Technology Solar Telescope (ATST) 4.24-meter primary mirror
uses a jet cooling system.
You are welcome to visit our eBay store for some of our stocked mirrors:
Why Lightweight Sandwich Mirrors?
Telescope mirrors are manufactured in a strictly controlled temperature
and humidity environment.  Each mirror is carefully measured after it
has reached equilibrium in our laboratory.  While cooling, gradients in
the mirror will cause deformation of the surface, and the aberrations
induced by these gradients will be proportional to the CTE of the
substrate.  These gradient-induced aberrations die out as the mirror
cools and equilibrates.
Jupiter Images by Emanuele De Giorgio with a Hubble 16" F/5 Sandwich Mirror
Mars Images by Emanuele De Giorgio with a Hubble 16" F/5 Sandwich Mirror