Products

Silicon (Si) Lenses
Low density and lightweight
  • Maximum diameter 300mm
  • Czochralski Si for MWIR, Float Zone Si for LWIR
  • Coating options: DLC coating, AR coating
  • Low cost, mechanical ruggedness, chemical resistance Inquire Us  
  • Specifications:

    Materials Silicon crystals Diameter Range ~300mm
    Diameter Tolerance -0.01/-0.03mm Thickness Tolerance +/-0.03mm
    Surface Quality 60/40 S/D Frings (N) 3
    Irregularity (delta N) 1 Centration 3'
    Chamfer 0.1-0.3mmx45 degree Coatings AR/AR@3-5micro DLC/AR@3-5micro

     

    Physical and Optical Properties:

    Transmission Range 0.12μm to 15 μm and and 30μm to >100 μm (1) Refractive Index 3.4223 @ 5 μm (1) (2)
    Reflection Loss 46.2% at 5 μm (2 surfaces) Absorption Coefficient 0.01 cm-1 at 3 μm
    Reststrahlen Peak n/a dn/dT 160 x 10-6 /°C (3)
    dn/dμ = 0 10.4 μm Density 2.33 g/cc
    Melting Point 1420 °C Thermal Conductivity 163.3 W m-1 K-1 at 273 K
    Thermal Expansion 2.6 x 10-6 / at 20°C Hardness Knoop 1150
    Specific Heat Capacity 703 J Kg-1 K-1 Dielectric Constant 13 at 10 GHz
    Youngs Modulus (E) 131 GPa (4) Shear Modulus (G) 79.9 GPa (4)
    Bulk Modulus (K) 102 GPa Elastic Coefficients C11=167; C12=65; C44=80 (4)
    Apparent Elastic Limit 124.1MPa (18000 psi) Poisson Ratio 0.266 (4)
    Solubility Insoluble in Water Molecular Weight 28.09
    Class/Structure Cubic diamond, Fd3m

    Silicon (Si) lenses manufactured using optical grade silicon are competent for light collimation, direction, and manipulation in the IR spectrum. There are two kinds of silicon, Czochralski Si, used for the 3-5μm MWIR range, and Float Zone Si, used for the 8-12μm LWIR range. It has a low density of half the magnitude of Ge or ZnSe, thus Si lens is ideal for weight-sensitive applications. Silicon is also harder and less brittle than germanium, with the additional virtue of chemical resistance and low cost.

    Curves:

    1. Transmission Curve of Silicon with No Coating

     

    2. Transmission Curve of Silicon Lens with AR/AR Coating at 3-5μm