Solar Glass 0787

Specially designed for use in the space exploration field, SCHOTT® Solar Glass 0787 has a wide range of technical advantages. These ensure long-lasting, stable performance and a continuing dual role, both protecting and enhancing the function of spacecraft for the entire length of their mission – and beyond.

Developed to explore space – and beyond

Protection against radiation

To ensure a space system functions well throughout the duration of a mission, its technology and hardware need to be effectively protected against particle radiation and UV-B and UV-C rays. Solar Glass 0787 absorbs that harmful light and minimizes the damage it causes.

High light transmission

Across the radiation spectrum from UV-A to NIR, Solar Glass 0787 achieves an outstanding level of transmission. This enables high performance and efficiency of photovoltaic systems, which spacecraft depend upon to function at the optimum level.

Solarization stable

The harmful radiation in space means that degradation is always a threat. The special material composition of Solar Glass 0787 is designed to prevent solarization or discoloration of the glass, enabling a stable optical performance for the lifetime of the mission.

High surface quality

The stable and reliable performance of a glass depends on its geometrical properties, and SCHOTT has the expertise to deliver top quality. All thicknesses and shapes are drawn with a fire-polished surface and homogenous geometry, producing consistently great results.

Material properties


1. Optical properties 

Optical Properties Value
Refractive index* ng 1.5184
Refractive index* nF' 1.5143
Refractive index* nF 1.5138
Refractive index* ne 1.5100 
Refractive index* nd 1.5080 
Refractive index* nD 1.5080 
Refractive index* nC' 1.5059 
Refractive index* nC 1.5055 
Refractive index* n1550 nm  1.4926 
Abbe value νe 60.4 
Photoelastic constant in (nm/cm)/Mpa 32.1 

* Refractive indices: Pretreatment of samples.
Condition as supplied ["as drawn"] 


2. Thermal properties

General thermal properties Unit Value
CTE (Coefficient of thermal expansion) α  in 10-6·K-1  (20 °C; 300 °C)  8.5 
Transformation temperature Tg in °C 568


Viscosities Viscosity lg ŋ in dPas Temperature in °C
Strain point 14.5 537
Annealing point 13.0 568
Softening point 7.6 762


3. Mechanical properties

Mechanical Properties
Unit Value
Density ρ in g/cm³ 2.51
Young's modulus E in kN/mm² 70.0
Poisson's ratio µ 0.216
Torsion modulus G in kN/mm² 29
Knoop hardness HK 0.1/20 470
Vickers hardness HV 0.2/25 560


 4. Chemical properties

Hydrolytic resistance (acc. to DIN ISO 719) Value
Class HGB 1
Equivalent of alkali per gram glass grains in µg/g < 31


Acid resistance (acc. to DIN 12116) Value
Class S 24
Half surface weight loss after 6 hours in mg/dm² 31


Alkali resistance (acc. to DIN ISO 695) Value
Class A2
Surface weight loss after 3 hours in mg/dm² 142


5. Electrical properties

Dielectric constant εr (at ϑ = 25 °C) Value
at 1 MHz 7.0
at 1 GHz 6.8
at 5 GHz 6.6


Dissipation factor tan δ (at ϑ = 25 °C)
at 1 MHz 54 · 10-4
at 1 GHz 82 · 10-4
at 5 GHz 114 · 10-4


Electric volume resistivity ρD in Ω·cm direct current
3 ·1015 ( ϑ = 20 °C)


6. Transmittance values


  Spectral transmittance

Graph showing the spectral transmittance of SCHOTT® Solar Glass 0787 between 200-3,200 nm wavelength


Graph showing the spectral transmittance of SCHOTT® Solar Glass 0787 between 200-500 nm wavelength



Transmittance values

Thickness in mm Τ400* in % Τ450* in % Τ500* in % Τ600* in %
0.100 91.7  92.3  92.1 


0.125  91.6  92.0  92.1  92.3 
0.150  91.4  91.8  91.9  92.2 

* Τ(λ) – individual values in %


Edge wavelength λc (Τ = 0.46) at thickness in mm Wavelength in nm
0.100 332
0.125  334 
0.150  336 


Τ in % arithmetic mean for the given λ - range at thickness in mm 200 nm to 300 nm 600 nm to 300 nm 450 nm to 1100 nm
0.100 4.9 92.4  92.4 
0.125  3.2  92.3  92.4 
0.150  2.0  92.2  92.2 


Transmittance values after a solarization treatment**:

Τ in % arithmetic mean for the given λ - range at thickness in mm 200 nm to 300 nm 600 nm to 300 nm 450 nm to 1100 nm
0.125 1.4 92.2 92.2

** the sample is irradiated for 3 hours using a  UV - F 400 lamp. The irradiation distance is 14 cm.




SCHOTT® Solar Glass 0787 is available as:

  • Cut-to-size substrates
  • Unpolished substrates and wafers

To find out more, please see the related products on the overview page.

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