Optimum Transmission Range:

Ideal Applications:

400 - 2.300 nm

 High accuracy interferometer mirror substrates

 Large astronomical telescope mirrors

 Ring-laser gyroscope elements

 Laser resonator distance gauges

Zerodur® is a highly homogeneous, glass ceramic whose thermal and mechanical properties are extremely stable over a wide temperature range. This porous-free material is a carefully chosen, temperature treated combination of a glass with a positive expansion coefficient and a quartz structure crystalline phase with a negative expansion coefficient. The resultant mixture provides a material with a near zero coefficient of thermal expansion. Zerodur® provides outstanding homogeneity, but due to absorption near the blue end of the visible spectrum, is rarely used in refractive applications.


  • Refractive index nd = 1,5424 (587,6 nm)
  • Abbe number: vd = 56,1
  • Stress optical coefficient K: 3,0 x 10-6 MPa-1
    (at 589,3 nm)


  • Density: 2,53 g/cm3
  • Young's Modulus: 90,3 GPa (mean value)
  • Poisson's ratio: 0,24
  • Knoop hardness : 620 ((HK 0,1/20 ; ISO 9385)


  • Coefficient of thermal expansion (CTE):
    • Class 0 materials: 0 ± 0,02 x 10-6/K
    • Class 1 materials: 0 ± 0,05 x 10-6/K
    • Class 2 materials: 0 ± 0,10 x 10-6/K

Quality Optics from a Trusted Supplier

American Owned & Operated

Esco Optics is a leading manufacturer of custom and catalog optics, precision optical components, and ITAR optics in the United States.

Military & Defense Supplier

As the leader for military and defense optics in the United States, Esco Optics adheres to the International Traffic in Arms Regulations.

ITAR Registered & Compliant

ITAR registered and compliant, Esco manufactures ITAR optics for all of its customers with the strictest confidentiality.