The main materials processed to adress a wide range of applications over a large spectrum (UV - VISIBLE - IR) are :
for any transmitive component finding application in the UV (down to 193 nm), Visible and IR (up to 2 microns) domains. Fused Silica has a high transmission and a low dispersion over this spectral range.
for any application in the IR domain from 2 microns up to 6 microns. Specific Si FZ (Float Zone) provides improved transmission on that range.
for any application in the IR range from 2 up to 14 microns. Germanium is of particular interest in the IR3 band (8-14 microns).