Claims
- 1. A fused silica glass member resistant to optical damage in ultraviolet radiation in the wavelength range between 190 and 300 nm having an internal transmission greater than or equal to 99.65%/cm at a wavelength of 193 nm and an absolute maximum birefringence along the use axis of less than or equal to 0.75 nm/cm.
- 2. The fused silica glass member of claim 1, wherein the fused silica member has a refractive index homogeneity along the use axis less than or equal to 1 ppm.
- 3. The fused silica member of claim 2, wherein the fused silica member exhibits a change in transmittance of less than 0.005/cm after the member has been irradiated with 1×1010 shots of 193 nm laser at 1.0 mJ/cm2/pulse.
- 4. The fused silica glass member of claim 1, wherein the fused silica member has a hydrogen molecule content less than or equal to 3×1017 molecules/cm3.
- 5. The fused silica member of claim 1, wherein the member is used as a lens in a photolithographic system.
- 6. A fused silica glass member resistant to optical damage in ultraviolet radiation in the wavelength range between 190 and 300 nm having an internal transmission greater than or equal to 99.75%/cm at a wavelength of 193 μm and an absolute maximum birefringence along the use axis of less than or equal to 0.5 nm/cm.
- 7. The fused silica glass member of claim 6, wherein the fused silica member has a refractive index homogeneity along the use axis less than or equal to 1 ppm.
- 8. The fused silica member of claim 7, wherein the fused silica member exhibits a change in transmittance of less than 0.005/cm after the member has been irradiated with 1×1010 shots of 193 nm laser at 1.0 mJ/cm2/pulse.
- 9. The fused silica glass member of claim 6, wherein the fused silica member has a hydrogen molecule content less than or equal to 2×1017 molecules/cm3.
- 10. The fused silica member of claim 6, wherein the member is used as a lens in a photolithographic system.
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application, U.S. Serial No. 60/325,950, filed Sep. 27, 2001 entitled Fused Silica Having High Internal Transmission and Low Birefringence.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60325950 |
Sep 2001 |
US |