Choosing the right Fused Silica for Optical Applications
Some may think fused silica is a simple material and there is little difference in which grade should be used, but when performance matters there are differences. We see ourselves as experts and hope to help you find the optimal solution for your product. Many factors can be considered before you choose the most suitable grade:
- Optical homogeneity
- Transmission and absorption
- Bubble or inclusion content
- Refractive index and dispersion
- Residual strain
- Fluorescence
- Resistance to light induced defects or irradiation
- Cost
Material Selection Guide
As a first guide to choosing the right fused silica grade from Heraeus, please use the following tables in the tabs. They give you advice on which material grades are suitable for which field of application and for which application wavelength. More information about the fields of application and the application wavelength can be found below.
Material Grades for Optical Applications
Material Grade | Application | Features |
HOQ® 310 | Optical elements | Basic optic grade, higher viscosity |
Infrasil® 301 / Infrasil® 302 | Near IR applications | Basic IR grade, higher viscosity, homogenized in functional direction (302) or all directions (301) |
Nerasil® | Mirror substrates, beam dump, cuvettes | Highly absorbent fused quartz |
Spectrosil 2000 | UV + VIS applications | Basic UV grade, improved UV damage resistance |
Suprasil® 1 / Suprasil® 2 ArF/KrF | Eximer grades | Best damage resistance to UV light (Excimer lasers) |
Suprasil® 1 / Suprasil® 2A | UV applications | Improved UV stability, homogenized in functional direction (2A) or all directions (1) |
Suprasil® 2B | UV + VIS applications | Basic UV grade |
Suprasil® 300 | IR applications | Extremely low OH content, basic synthetic grade for IR |
Suprasil® 3001 / Suprasil® 3002 | All IR applications, e.g. IR laser, laser material processing, low absorption IR applications | Extremely low OH content, homogenized in functional direction (3002) or all directions (3001) |
Suprasil® 311 / Suprasil® 312 | UV + VIS Applications | Basic UV grade, synthetic grade homogenized in functional direction (312) or all directions (311) |
Suprasil® 313 | Laser debris shield, fused silica optics with standard specifications | Cost efficient basic grade |
Suprasil® UVL | UV applications | Damage resistance to UV light |
Sensing / Imaging
UV
VIS
NIR
Application Wavelength
160 - 280 nm 280 - 400 nm
380 - 780 nm
780 - 3600 nm
HOQ® 310
- +
+
+
Infrasil® 301
- +
+
+
Infrasil® 302
- +
+
+
Spectrosil® 2000
+ +
+
0
Suprasil® 1
+ +
+
0
Suprasil® 2 Grade A
+ +
+
0
Suprasil® 2 Grade B
+ +
+
0
Suprasil® 1 ARF / KRF
+ +
+
0
Suprasil® 2 ARF / KRF
+ +
+
0
Suprasil® UVL
+ +
+
0
Suprasil® 300
0 +
+
+
Suprasil® 3002
0 +
+
+
Suprasil® 3001
0 +
+
+
Suprasil® 311
+ +
+
0
Suprasil® 312
+ +
+
0
Suprasil® 313
+ +
+
0
Power Transmission
UV
VIS
NIR
Application Wavelength
160 - 280 nm 280 - 400 nm
380 - 780 nm
780 - 3600 nm
HOQ® 310
- 0
+
+
Infrasil® 301
- 0
+
+
Infrasil® 302
- 0
+
+
Spectrosil® 2000
0 0
+
0
Suprasil® 1
0 0
+
0
Suprasil® 2 Grade A
0 0
+
0
Suprasil® 2 Grade B
0 0
+
0
Suprasil® 1 ARF / KRF
+ +
+
0
Suprasil® 2 ARF / KRF
+ +
+
0
Suprasil® UVL
+ +
+
0
Suprasil® 300
- -
+
+
Suprasil® 3002
- -
+
+
Suprasil® 3001
- -
+
+
Suprasil® 311
0 0
+
0
Suprasil® 312
0 0
+
0
Suprasil® 313
0 0
+
0
Radiation Environment
UV
VIS
NIR
Application Wavelength
160 - 280 nm 280 - 400 nm
380 - 780 nm
780 - 3600 nm
HOQ® 310
- -
-
-
Infrasil® 301
- -
-
-
Infrasil® 302
- -
-
-
Spectrosil® 2000
0 0
+
0
Suprasil® 1
0 0
+
0
Suprasil® 2 Grade A
0 0
+
0
Suprasil® 2 Grade B
0 0
+
0
Suprasil® 1 ARF / KRF
+ +
+
0
Suprasil® 2 ARF / KRF
+ +
+
0
Suprasil® UVL
+ +
+
0
Suprasil® 300
- -
+
+
Suprasil® 3002
- -
+
+
Suprasil® 3001
- -
+
+
Suprasil® 311
0 0
+
0
Suprasil® 312
0 0
+
0
Suprasil® 313
0 0
+
0
Fields of Applications
Because optical applications are very diverse, we have clustered the applications into three rather broad fields in order to allow an easier selection.
Application Wavelength
To choose the right material grade for your application, it is important to know in which wavelength region your application operates.
Ultraviolet Spectrum
The focus of your application is on the wavelength from
180 – 400 nm:
- VUV: < 190 nm
- DUV: 190 – 280 nm
- UV: 280 – 400 nm
The most important optical properties for this wavelength region are high transmission and excellent purity, no fluorescence, outstanding damage resistance against UV or other high-energy radiation. Typical applications in the UV wavelength region include: Microlithography, Spectroscopy, Laser Fusion projects, or other applications irradiated by Excimer laser or UV lamps.
- Prisms, Lenses and Beamsplitters
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 materialsRecommended Materials:
We recommend the following materials for their 3D homogeneity (indicated by +, ++, +++). To help with the selection, we indicate additional information. Nevertheless, feel free to contact our experts.- Suprasil 311 (3D:+++)
- Suprasil 3301 (highest VUV transmission, 3D:+++)
- Suprasil 1 (good radiation hardness, low fluorescence, 3D:++)
- Suprasil 1 ArF/KrF (highest radiation hardness, lowest fluorescence, 3D:++)
- Windows, Filters, Polarizers and Lightpipes
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® 2 ArF/KrF (highest radiation hardness and lowest fluorescence, homogeneity: ++)
- Suprasil® 2B (good radiation hardness and low fluorescence, homogeneity: +)
- Spectrosil 2000 (low fluorescence, homogeneity:+)
- Suprasil® UVL (highest radiation hardness and lowest fluorescence, homogeneity:+)
- Wafer, Substrates, Debris Shields and Mirrors
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, low OH content)
- Unusual and special optics
Optical components become increasingly more complex and evolve from the standard optical components some decades 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.
Visible Spectrum
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.
- Prisms, Lenses and Beamsplitters
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 materialsRecommended Materials:
We recommend the following materials for their 3D homogeneity (indicated by +, ++, +++). To help with the selection, we indicate additional information. Nevertheless, 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:++)
- Windows, Filters, Polarizers and Lightpipes
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:+)
- Wafer, Substrates, Debris Shields and Mirrors
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)
- Suprasil® 300 (OH < 1ppm, subject to export controll)
- HOQ® 310 (natural quartz glass)
- Unusual and special optics
Optical components become increasingly more complex and evolve from the standard optical components some decades 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.
- Non Transmissive Optics
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.
Near Infrared Spectrum
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 below.
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.
- Prisms, Lenses and Beamsplitters
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 materialsRecommended Materials:
We recommend the following materials for their 3D homogeneity (indicated by +, ++, +++). To help with the selection, we indicate additional information. Nevertheless, 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:++)
- Windows, Filters, Polarizers and Lightpipes
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:++)
- Wafer, Substrates, Debris Shields and Mirrors
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)
- HOQ® 310 (natural fused quartz, OH < 30ppm)
- Unusual and special optics
Optical components become increasingly more complex and evolve from the standard optical components some decades 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.
Near Infrared Spectrum - Video
Tools and Services
In the selection process for the most suitable fused silica grade the transmission performance is among the first criteria. Please check our transmission calculator. As an additional service, we offer the possibility to search our portfolio for existing part numbers.
