For applications in the visible wavelength range from 380 - 780 nm fused silica is used due to its higher absolute transmission compared to other optical materials and it's extreme radiation hardness compared to standard optical glasses. In extreme environments like high temperature, chemical contact and high mechanical stress fused silica shows its excellent properties.
Optical Materials for VIS Applications


Prisms, lenses and beam splitters are typically the most critical optical elements. The quality of these components contributes significantly to the performance of the entire optical system.. In such optical elements the light path of different rays can be of different length in the material. Especially for the larger optical components, these rays may see locally varying refractive indexes. Therefore, for superior optical performance it is important that there is no optical distortion in any propagation direction. An isotropic optical material with a homogenous refractive index distribution is necessary. Heraeus Conamic has a unique process to provide true 3D materials with outstanding optical properties.
More information on 3D materials
Recommended Materials:
We recommend the following materials for their 3D homogeneity (indicated by +, ++, +++). To help with the selection, we indicate additional information. Never the less, feel free to contact our experts.
- Suprasil® 311 (3D:+++)
- Suprasil® 3301 (highest VUV transmission, 3D:+++)
- Suprasil® 1 (good radiation hardness, low fluorescence, 3D:++)
- Infrasil® 301 (natural quartz glass, 3D:++)

Optical components like windows, filters, polarizers or light guides require the light to pass through the functional direction with minimized distortions. Fused silica optics (mostly plano-plano) have an excellent homogeneity and can be used for a wide range of applications - not just as a transmissive window in harsh environments, also as base material for optical filters and polarizers.
Recommended Materials:
We recommend the following materials for their homogeneity in functional direction (indicated by +, ++, +++). To help with the selection, we indicate additional information. Never the less, feel free to contact our experts.
- Suprasil® 312 (basic material, homogeneity: +++)
- Suprasil® 3302 (improved VUV transmission, homogeneity: +++)
- Suprasil® 2A (good radiation hardness and low fluorescence, homogeneity: ++)
- Suprasil® 2B (good radiation hardness and low fluorescence, homogeneity: +)
- Spectrosil 2000 (low fluorescence, homogeneity:+)
- Infrasil® 302 (natural quartz glass, homogeneity:++) Data Sheet
- HOQ® 310 (natural quartz glass, homogeneity:+)
Mirrors, Wafers, Debris Shields and Substrates all rely on either the surface, or a very thin layer of material. Optical homogeneity is not the prime focus for these applications. Optical parameters like excellent transmission, very good coefficient of thermal expansion and other mechanical, thermal and chemical properties might be more important.
Recommended Materials:
- Spectrosil 2000 (good radiation hardness)
- Suprasil® 313 (good homogeneity, medium OH content) Data Sheet
- Suprasil® 300 (OH < 1ppm, subject to export controll)
- HOQ® 310 (natural quartz glass)

Increasingly optical components become more complex and evolve from the standard optical components some decade ago. Driven by the complexity of the applications in industry and science, specifications are much tighter, dimensions can be very unusual and sizes can go up to 1,5m. Heraeus Conamic was involved in a lot of projects, where a customer tailored optical component was required. Our long-term R&D expertise enables us to support you in every unusual, special optics request.
Please contact us directly to discuss your problem and find a solution.

For some optical components non-transparent fused silica can be used.
A typical non-transparent optical component is an absorber. Heraeus has developed a special fused silica - Nerasil® -, that is intentionally doped to absorb over a broad wavelength region. It appears black and is used in spectroscopy applications or as mirror substrates. If cut very thin, it can be used as a strong attenuator for high intensity radiation.
Please feel free to contact our experts for additional information!