Optical window
US6287478A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | Sep 11, 2001 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/06
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An optical dome or window formed of a composition which is transmissive to infrared frequencies in the range of from about 1 micron to about 14 microns and which is relatively opaque to substantially all frequencies above about 14 microns consisting essentially of a compound taken from the class consisting of group III-V compounds doped with an element taken from the class consisting of shallow donors and having less than about 1.times.10.sup.7 atoms/cc impurities and having less than about 1.times.10.sup.15 parts carbon. The shallow donors are Se, Te and S, preferably Se, with the Se concentration from 5.times.10.sup.15 atoms/cc to 2.times.10.sup.16 atoms/cc. The group III-V compound is preferably GaAs or GaP. The group III-V compound is fabricated by providing a graphite vessel containing a graphite cloth with the molten group III element thereover, a shallow donor and water containing boron oxide thereover, loading the group V element into the vessel in essentially stoichiometric amounts to provide the molten compound of the group III and group V elements and cooling the molten compound progressively in a vertical direction from bottom to top to form a crystal by causing growth …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.