Materials

LAYERTEC offers a wide range of substrates for your products. To help you to decide for the right one we offer many ways of support. Here you cen see transmission curves of selected materials. Please feel free to contact us for further information.
YAG (undoped)SapphireBaF2CaF2Infrasil 1)Fused silicia (UV)BK7 2)SF10 2)
Wavelength range free of absorption400 nm - 4 μm400 nm - 4 μm400 nm - 1 0μm130 nm - 7 μm300 nm - 3 μm190 nm - 2 μm 3)400 nm - 1.8 μm400 nm - 4 μm
 
Refractive index at
200 nm1.495161.55051
300 nm1.454031.48779
500 nm1.84501.7751.4791.436481.462331.462431.54121.7432
1 μm1.81971.7561.4681.428881.450421.450511.50751.7039
3 μm1.78551.711.4611.417851.441941
5 μm1.6241.4511.39896
9 μm1.4081.32677
 
Absorbing in 3 μm regionnonononoyesyesyesyes
Absorbing in 940 nm region For higher power applications at 940 nm we recommend the fused silicia SUPRASIL 300 1) and SUPRASIL 3001 / 3002 1)
Birefringencenoyesnono4)nononono
Thermal expansion coefficient [10-6 K] 5)7519180.50.578
Resistance against temperature
gradients and thermal shock
highhighvery lowlowhighhighhighmedium
LAYERTEC standard specifications for substrates with Ø 25 mm
surface roughness (rms)0.2 nm0.5 nm1 nm0.15 nm0.15 nm0.15 nm0.5 nm0.5 nm
Flatness (plane surface) (546 nm)λ / 4λ / 4λ / 2λ / 10λ / 10λ / 10λ / 10λ / 10
Surface figure (curved) (546 nm)λ / 4λ / 2λ / 4λ / 4λ / 4λ / 4λ / 4
Surface quality (ISO 10110)5 / 1 x 0.025
L2 x 0.004
5 / 3 x 0.025
L20 x 0.0025
5 / 2 x 0.4
L20 x 0.0063
5 / 3 x 0.025
L1 x 0.0025
5 / 1 x 0.025
L1 x 0.001
5 / 1 x 0.025
L1 x 0.001
5 / 2 x 0.4
L1 x 0.001
5 / 2 x 0.4
L x 0.001
1)Registred trademark of Heraeus Quarzglas GmbH & Co. KG
2)Registred trademark of SCHOTT AG
3)Absorption band within this wavelength range, please see transmission curve
4)Measurable effects only in the VUV wavelength range
5) The values given here are rounded, because the measurements of different authors in the literature are inconsistent.
Please note that the thermal expansion coefficient of crystals depends also on the crystal orientation.
YAG undoted transmisson curve
sapphire transmisson curve
calcium fluoride transmisson curve
barium fluoride transmisson curve