Telescope Diagonals

​Telescope Diagonals

Get Your Diagonals From Us Today!

​Telescope Diagonals

​Made From Precision Annealed Pyrex, Fused Silica Or Zerodur

​Diagonal Minor Axis Up To 8"​

Diamond generated substrates. True 45 degree elliptical diagonal. 1/20th wave RMS.

​Coated with Enhanced Aluminum and overcoated with hard Silicon Dioxide with Reflectance of 95% average in the visible.

Minor Axis

Substrate

Material

​Price

​Substrate

​Material

​Price

Substrate

​Material

​Price

​1.0"

​​Pyrex

​$55.00

​Fused Silica

​$85.00

​Zerodur

​$90.00

​1.32"

​​Pyrex

​$75.00

​​Fused Silica

​$110.00

​Zerodur

​$120.00

​1.52"

​​Pyrex

​$95.00

​​Fused Silica

​$140.00

​Zerodur

​$150.00

​1.83"

​​Pyrex

​$135.00

​​Fused Silica

​$185.00

​Zerodur

​$195.00

​2.14"

​​Pyrex

​$180.00

​​Fused Silica

​$240.00

​Zerodur

​$255.00

​2.60"

​​Pyrex

​$230.00

​​Fused Silica

​$295.00

​Zerodur

​$315.00

​3.10"

​​Pyrex

​$350.00

​​Fused Silica

​$335.00

​Zerodur

​$350.00

​3.50"

​​Pyrex

​$465.00

​​Fused Silica

​$525.00

​Zerodur

​$560.00

​4.0"

​​Pyrex

​$825.00

​​Fused Silica

​$965.00

​Zerodur

​$995.00

​4.25"

​​Pyrex

​$1250.00

​​Fused Silica

​$1475.00

​Zerodur

​$1525.00

​4.50"

​​Pyrex

​$1360.00

​​Fused Silica

​$1595.00

​Zerodur

​$1675.00

​4.75"

​​Pyrex

​$1490.00

​​Fused Silica

​$1695.00

​Zerodur

​$1750.00

​5.00"

​​Pyrex

​$1625.00

​​Fused Silica

​$1775.00

​Zerodur

​$1895.00

​Custom Size

up to 8" Minor Axis

​Pyrex

​Quote

​Fused Silica

​Quote

​Zerodur

​Quote

​Delivery from stock or in the case of larger minor axis and custom we can delivery in approximately 5 weeks from blank to coated mirror.

​Information about the different materials

  • ​Pyrex
  • ​Fused Silica
  • ​Zerodur

Zerodur is a glass ceramic that Schott developed for optical, opto-electronic and precision engineering applications. Zerodur is an inorganic, non-porous material which has a crystalline phase and a glassy phase. This results in an extremely low thermal expansion which in certain temperature ranges can even be zero or slightly negative. 

Zerodur is a material of the highest homogeneity, and even in large pieces with dimensions of several meters displays thermal and mechanical characteristics with nearly unmeasureable deviations.

​Extreme low coefficient of expansion at 0.050 x 10-6/K 


​This material takes an excellent polish to extremely smooth surface roughness below 1 nm RMS

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