Gas replenishment method and apparatus for excimer lasers
US5440578A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1993 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Jul 16, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/225
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An excimer gas laser using a fluorine/krypton/neon gas mixture is provided with separate fluorine/krypton/neon and krypton/neon gas sources for use in replenishing the gas mixture. A bleed-down mechanism is also provided for draining a portion of the gas mixture from the excimer laser. A control mechanism controls operation of the separate fluorine/krypton/neon and krypton/neon sources and the bleed-down mechanism to selectively vary the gas mixture within the excimer laser to maintain an overall optimal laser efficiency. Preferably, the control system monitors operational parameters of the excimer laser including gain, wavelength, bandwidth and pulse rate, to determine whether the gas mixture within the excimer laser may have changed from an optimal mixture. The control system controls operation of the separate fluorine/krypton/neon and krypton/neon sources to compensate for changes in the operation parameters of the laser to thereby maintain high overall laser efficiency. Alternatively, gas replenishment is controlled subject to pre-determined empirically-based gas replenishment strategies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.