Excimer laser with greater spectral bandwidth and beam stability
US5898725A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1997 |
| Grant date | Apr 27, 1999 |
| Priority date | — |
| Expiry date | Jan 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/08009
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An excimer laser having reduced spectral bandwidth variation is provided. The laser has an assembly of components comprising a beam expander having at least two prisms that reduces the spectral bandwidth of the laser beam that is passed through the assembly. At least one of the prisms of the beam expander is made of a thermally stable material, wherein the material has an coefficient of absorption of no more than about 0.1 percent/cm for light having the desired wavelength, a rate of change of refractive index with temperature of no more than about 2.3.times.10.sup.-6 .degree.C..sup.-1, a thermal conductivity of at least about 9.71 W/m-.degree.C. at 20 deg C., and/or a coefficient of thermal expansion of at least about 9.times.10.sup.-6 (deg C.).sup.-1. In a preferred embodiment, the stability of beam profile is improved, the variation in spectral bandwidth of the beam from the laser is reduced, the spectral bandwidth itself is also reduced, and the laser exhibits greater voltage stability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.