Purification of laser gases
US5073896A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1991 |
| Grant date | Dec 17, 1991 |
| Priority date | — |
| Expiry date | Apr 18, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/225
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Purification of the gas mixture used in an excimer laser is carried out by cooling such mixture in a cryogenic trap to a temperature that is low enough that the lasting gas or gases (e.g. krypton, xenon, fluorine, hydrogen chloride) and the impurities are all substantially fully condensed. This temperature is nevertheless sufficiently high that the buffer gas (neon or helium or a mixture thereof) remains substantially all in gaseous form. The trap is then isolated from the laser vessel and the condensed gases therein are treated to remove at least the condensed impurities from the system. In a xenon chloride laser the condensed impurities can be effectively separated from the condensed laser gases by heating, i.e. differential distillation. After this has been done, the laser gases are returned to the laser vessel. In those instances in which such separation by differential distillation is not practicable, e.g. a krypton fluoride laser, some or all of the condensed lasing gas or gases is removed from the system together with the condensed impurities. Fresh charges of these lasing gases are then supplied to the laser vessel as required. The procedure is characterized by the fact tha…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.