Fused quartz is produced by fusion at very high temperatures of naturally occurring high purity quartz rock crystal. Flame fused quartz has very good transmission at near ultraviolet and visible wavelengths with useful transmission range form 260nm to above 200nm. Fused quartz polished windows are made from a range of quartz grades available which are dependent upon visual quality required and transmission.

Fused quartz polished windows are manufactured from a range of grades of materials from major quartz processors from around the world. Types include: Vitrosil 055 – O66, Heraeus: Herasil, G E Quartz: 214, 124.

Fused quartz plano polished windows are fabricated from a quartz ingot by core drilling or sawing a section from the ingot then slicing over thickness. The surfaces are then lapped and mechanically optically polished using various polishing techniques. More information can be seen in optical window custom processing page for a selection of quality polished fusedquartz windows see stock quartz windows. Other grades of fused quartz include commercial and industrial grades used for their thermal and mechanical properties not for their optical qualities. These are from drawn materials and rolled plate form which can be cut into diameters and discs.

Fused quartz optical windows are used in a wide range of applications and products, typical examples include: substrates, optical flats, discs, spectrophotometer cells, flame detection systems, coating pieces and instrument windows.