Damage resistant up to 10 J/cm2
UV fused silica for excellent thermal stability
Low wavefront distortion
Hard refractory coatings
25.4 and 50.8 mm diameters
Our high-energy laser windows are specially designed to eliminate losses in vacuum cell applications and can be used as vacuum windows, convection barriers, or interferometer compensator plates.
UV Grade Fused Silica is synthetic amorphous silicon dioxide of extremely high purity providing maximum transmission from 195 to 2100 nm. This non-crystalline, colorless silica glass combines a very low thermal expansion coefficient with good optical qualities, and excellent transmittance in the ultraviolet region. Transmission and homogeneity exceed those of crystalline quartz without the problems of orientation and temperature instability inherent in the crystalline form. It will not fluoresce under UV light and is resistant to radiation. For high-energy applications, the extreme purity of fused silica eliminates microscopic defect sites that could lead to laser damage.
A 30 arc-min wedge between the polished faces eliminates fringe patterns and cavity feedback. Highly parallel flats are unsuited for use as reference elements in interferometers as reflections from both surfaces follow the same optical path toward the viewer or imaging system, resullting in undesired large period ghost fringes.
These optics are precision polished, select grade fused silica coated with hard refractory multilayers for very high damage threshold.
| Material | UV grade fused silica |
| Surface Flatness | ≤λ/10 at 632.8 nm over the clear aperture |
| Clear Aperture | >central 80% of diameter |
| Surface Quality | 15-5 scratch-dig |
| Diameter Tolerance | +0/-0.13 mm |
| Thickness Tolerance | ±0.38 mm |
| Wedge | 30 ±15 arc min |
| Chamfers |
25.4 mm: 0.25–0.76 mm face width x 45° ±15° 50.8 mm: 0.38–1.14 mm face width x 45° ±15° |
| Antireflection Coating |
broadband, multilayer coating, Ravg <0.5% per surface at 0° over the specified wavelength range |
| Durability | MIL-M-13508, MIL-C-675, MIL-C-14806 |
| Cleaning |
Non-abrasive method, acetone or isopropyl alcohol on lens tissue recommended (see How to Clean Optics) |
| Damage Threshold | 10 J/cm2 @ 20 nsec pulses, 20 Hz, at 1064 nm, typical |
| Dimension (mm) | |||
|---|---|---|---|
| Model | ø A | ø B | C |
| 10Q20 | 25.4 | 20.3 | 6.10 |
| 20Q20 | 50.8 | 40.6 | 9.40 |