Optical Materials for NIR Applications

Video: Absorption in Laser Material processing

For IR applications in the wavelength range from 780 - 3600 absorption can play a major role.

Absorption is the root cause of thermal lensing. The optimal performance depends on the absorption value of the specific fused silica grade. Metallic impurities and OH molecules are sources of absorption. A short video explaining the context can be found on the left side.

As the price of fused silica typically scales with increasing purity, it is economically important to make the right choice and not overspec. However, if the highest quality is needed, we can deliver it in large sizes too.

For details about our NIR fused silica grades, please check the following brochure: Fused Silica for Applications in the Near Infrared .

Beam path in a retro reflector / Challenges: Backreflection in the same direction.
Beam path in a retro reflector / Challenges: Backreflection in the same direction.

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® 3001 (OH < 1ppm, lowest absorption, 3D:++)
  • Suprasil® 311 (OH < 250ppm, 3D:+++)
  • Infrasil® 301 (natural fused quartz, OH < 8ppm, 3D:++)

Fused silica ingot
Typical window out of fused silica

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® 3002 (OH < 1ppm, lowest absorption, homogeneity:++)
  • Suprasil® 312 (OH < 250ppm, homogeneity:+++)
  • Infrasil® 302 (natural fused quartz, OH < 8ppm, 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:

  • Suprasil® 300 (OH < 1ppm, lowest absorption)
  • Suprasil® 313 (OH < 250ppm, good homogeneity) Data Sheet
  • HOQ® 310 (natural fused quartz, OH < 30ppm)

Fused silica lens and blank
Customer tailored optical components

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.