Silicon is used as an optical window primarily in the 3 to 5 micron band and as a substrate for production of optical filters. 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. Large blocks with polished faces are also employed as targets in neutron physics experiments.Silicon is grown by Czochralski pulling techniques (CZ) and contains some oxygen which causes an absorption band at 9 microns. To avoid this, material can be prepared by a Float-Zone (FZ) process. Optical silicon is generally lightly doped ( 5 to 40 ohm cm) for best transmission above 10 microns. Silicon has a further pass band 30 to 100 microns which is effective only in very high resistivity uncompensated material.

The following products from Si are available:

  WINDOWS

  BLANKS

  LENSES (spherical pl-cvx, spherical bi-cvx)