Z-Cut Cultured Crystal Quartz Windows
BPO supplies optical quality cultured quartz windows and blanks. Z-oriented components are available up to 4.000" in diameter. Very few materials match the useful transmission range and physical properties of optical quality cultured quartz. This material is reproducible, available and affordable.
For over 20 years, BPO specialists have been selecting appropriate quality and cuts of crystal quartz for optical and electronic applications. Critical visual inspection, x-ray diffraction orientation of one or more planes and acid-etch topographical evaluation ensure the most appropriate material to fill your specific needs.
Our windows are chemically polished. The process used to remove the last few microns of material from each surface is basically a mild etch and produces a true single-crystal surface. The polished windows meet or exceed most standard commercial quality requirements. While flatness and parallelism vary with diameter and thickness, wedge is usually less than 0.0005".
For more stringent processing requirements, we can supply inspected, oriented blanks for final finishing at an optical facility of your choice.
A representative inventory of finished windows is maintained. Diameters from 0.500" to 3.000", and thicknesses from 0.020" to 1.000" are available. UV grade windows and blanks are available for more demanding optical and electronic applications. We regularly supply crystal quartz substrates as thin as 0.001", and radiation absorption plates to 2.000" in thickness.
Standard Tolerances
| Diameter | +/- 0.002" |
| Thickness | +/- 0.002" |
| Surface Finish |
Chemical polish: meets or exceeds 40-20 with respect to processing induced artifacts |
| Flatness | Within 5 waves at 6:1 ratio |
| Parallelism | Within 0.0005" |
| Orientation | +/- 30 minutes |
| Minimum edge chamfers |
Other orientational and dimensional tolerances available
Material Characteristics
| Useful transmission range | 0.15 to 3.5 microns |
| Far IR | -50 to 200+ microns |
| Inclusions | 3 per cc (greater than 25 microns) |
| Optical homogeneity | 1/10th fringe per inch (UV grade) |
| Optical activity parallel to Z axis | 21° 43'/mm (sodium light) |
| Index of refraction | 1.55 (visible light) |
| Physical / Electronic Properties | |
| Chemical formula | SiO2 |
| Crystal class | Trigonal |
| Density | 2.66 x 103 kg/m3 @ 25°C |
| Melting point | 1750°C |
| Curie point | 573°C |
| Moh's hardness | 7 |
| Specific gravity | 2.649 @ 20°C |
| Dielectric constant | e11 = 4.58 e33 = 4.70 |
| Molecular weight | 60.1 |
| Solubility | Non-hydroscopic in most atmospheric liquids |
| Expansion coefficients | At 0°C (10-6): parallel to Z -7.0 perpendicular to Z -12.9 |
