Fused Silica
Fused Silica-UV
Most customers' needs can be met with two standard materials: FS-UV and FS-IR.
(amorphous silicon dioxide) is produced synthetically from high purity silicon by flame hydrolysis. It differs by its high UV-transmittance from natural Fused Silica, molten from crystalline quartz.
UV-FS offers:
• broad transmission range
• low thermal expansion coefficient, providing high thermal stability and resistance to thermal shocks
• thermal operating range up to 800 °C
• great hardness and resistance against scratches
• very high resistance to radiation darkening
• absence of bubbles and impurities
Even it is called UV-FS normally it is the standard substrate material for a use in UV, VIS and NIR.
There is a wide range of different substrate materials available, varying in homogeneity, grades of laser induced fluorescence and content of bubbles, inclusions and OH.
LASEROPTIK often uses SQ0, SQ1 (former Q0, Q1, Q2), Suprasil® 1+2, Corning 7980® or NIFS-U®.
In the UV-range we recommend to use optimized materials like SQ0 / SQ1 E-193 or E-248 for lowest losses. Other materials can be supplied as well.
Fused Silica-IR
IR absorption of FS is caused by OH-chemical bond content, most relevant at wavelengths near the water absorption band at 2.7 µm but also critical at 940 nm.
Reduction in OH can be assured by melting high quality quartz or special manufacturing techniques, but mostly at the sacrifice of UV transmittance.
A common material is Infrasil®. For high power applications, especially in the range of the OH-waterbands we recommend a material with lowest OH-content, like Corning 7979®, Suprasil® 300 or Suprasil® 3001 + 3002.
Overview of the Fused Silica classes used by LASEROPTIK
![Typical internal transmittance Ti [%] of the FS-LO classes, 10 mm thickness](/data/images/Diagramme/Substrate/Standard/Dia_Subs_Fused-Silica-Classes.png "Typical internal transmittance Ti [%] of the FS-LO classes, 10 mm thickness")
Typical internal transmittance Ti [%] of the FS-LO classes, 10 mm thickness
Classification of the FS types
Useable transmission ranges of the FS-LO classes
