Fused Silica (IR Grade) (SiO2)

Fused silica is often used in near infrared systems performing in the 0.8-2.5μm spectral region. It is also frequently used at the popular 1.064μm Nd:YAG laser wavelength. The material has high homogeneity and good transmission in the visible and near infrared spectral regions. Cost of the material ranges widely by type and purity. However the most common Fused Silica for infrared use is quite a bit more expensive than Silicon and slightly less expensive than Calcium Fluoride or ZnS Multispectral grade. Due to the materials inherently hard SiO2 amorphous structure, the material is not diamond turnable. Typical specifications for surface quality in the near infrared regions are a 40-20 scratch dig.
 
Refractive Index and Optical Transmittance curve----
Refractive Index(No=Ordinary Ray):
µm    No µm    No µm    No
2.0    1.438        
       
Optical Transmittance Curve of IR grade fused Silica:
fused-silica-sio2-ir Transmittance
 
Special properties of IR grade Fused Silica-------------

Transmission range: 0.25um to 3.5um

Density: 2.202g/cm3.

Thermal Expension: 5.5x10-7 / °C@20 to 320°C.

Typeical application:Thermal imaging, Astronomical, Microlithography, Excimer laser applications, Nd:YAG laser applications.

Products manufactured:Lenses, Windows, Wedges, Optical Beamsplitters, Optical Filters, Prism.

Surface finish:Fused Silica polishes extremely well and polishes of 10-5, or 20-10 scratch-dig are achieved at extra costs respectively, mainly for UV and visible applications.

Surface figure:In the infrared, typical surface figure ranges from 1/4 wave to 2 waves @0.6328μm and are specified depending on the system performance requirements.

AR coating options:Typical available infrared coatings are a BBAR from 0.8- 2.5μm and an AR coating for 1.064μm wavelength.
Product Notes:------------ --------------------------------------

Fused Silica is the glassy form of Quartz and is thus isotropic. Fused Silica is tough and hard and has a very low expansion. Normal varieties of Fused Silica contain water which gives strong absortion in the IR.

REFERENCES: (1) Handbook Optical Constants, ed Palik, V1, ISBN 0-12-544420-6

Data provided is extracted from our technical handbook of materials. While every attempt has been made to verify the source of the information, ultiQuest Technology accept no responsibility for accuracy of data

 Contact
If you have any questions or comments, please contact us by filling-in the mail form.

 
Copyright 1999-2011 Ultiquest Technology Ltd. | Privacy Policy | Terms of Use | Web Mail Site Credits