Introduction:Silicon is commonly used as substrate material for infrared reflectors and windows in the 1.5 - 8 micron region. The strong absorption band at 9 microns makes it unsuitable for CO2laser transmission applications, but it is frequently used for laser mirrors because of its high thermal conductivity and low density. Silicon is also useful as a transmitter in the 20 micron range.
CASTECH supply Silicon Lens, Mirrors and Windows with：
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Diameter
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+0/-0.10mm
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Length
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+/-0.2mm
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Chamfer
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0.20+/-0.10mm @ 45°
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Surface Figure (power/irregularity) at 0.63µm
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1.0 fringe/0.5 fringe
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Parallelism
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< 40 arc Seconds
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Perpendicularity
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< 5 arc min
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Surface Quality
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40/20Scratch/Dig
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Tighter Specifications are also available upon customer's requirements.
Main Properties of Si Materials：
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Crystal Class
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Cubic
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Lattice Parameter
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a=5.43Å
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Melting Point
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1417℃
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Mohs Hardness
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7
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Transmission Band
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1.5-8um
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Density
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2.329g/cm3
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Young’s Modulus
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130.91 GPa @40℃
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Thermal Conductivity
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1.63W/cm/K
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Specific Heat
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0.18cal/g/K @25℃
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Thermal Expansion
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2.6x10-6/℃ @20℃
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Refractive Index
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Wavelength, µm
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1.40
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1.50
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1.66
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1.82
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2.05
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2.50
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3.50-5.00
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6.00-25.00
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Refractive Index
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3.49
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3.48
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3.47
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3.46
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3.45
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3.44
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3.43
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3.42
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