The 20RQ00UB.2 low GVD 50/50 Beamsplitter for Ultrashort Pulses is specially designed to manage the femtosecond pulse to minimize the pulse dispersion and wavefront distortion of reflected and transmitted light. The beamsplitter is for S-polarized light and is coated with UB.2 providing a 50/50 split at 45° angle of incidence from 700–950 nm. The back surface has an antireflection coating to minimize surface reflection losses and eliminate ghost images. A thin UV grade fused silica substrate, with λ/10 wavefront distortion, is used to reduce pulse dispersion from the substrate material. For the UB.4 coating group velocity dispersion is between +50 fs2 and -180fs2 over 680-1080 nm for p polarized light at 45° angle of incidence. UB.4 coated beamsplitter can be used to split the P polarized output beam in 50/50 from Spectra Physics ultrafast amplifiers and oscillators namely Solstice and Spitfire, and Mai Tai. This 50.8 mm diameter beamsplitter is designed to minimize pulse dispersion and maximize bandwidth for beam sampling and autocorrelation measurements of ultrafast laser pulses.
| Model | 20RQ00UB.2 |
|---|---|
| Shape | Round |
| Type | Beamsplitter |
| Material | UV Grade Fused Silica |
| Diameter | 2.0 in. (50.8 mm) |
| Thickness | 0.12 in. (3.0 mm) |
| Surface Quality | 40-20 scratch-dig |
| Surface Accuracy | ≤λ/10 at 632.8 nm over the clear aperture |
| Angle of Incidence | 45 ° |
| Coating (First surface) | Rs=50±5% for 700-950 nm @ 45° (BS.2) |
| Coating (Second surface) | 660-1000 nm (NC.2) Multilayer Antireflection |
| Thickness Tolerance | ±0.25 mm |
| Wavelength Range | 700 to 950 nm |
| Wedge | ≤3 arc min |
| Wavefront Distortion | ≤λ/10 at 632.8 nm over the clear aperture |
| Orientation | Beam should enter surface marked with an arrow |
| Chamfers | 0.5 mm face width |
| Chamfers Angle/Tolerance | 45° ± 15 ° |
| Clear Aperture | > central 80% of diameter |
| Cleaning | Non-abrasive method, acetone or isopropyl alcohol on lens tissue recommended see Care and Cleaning of Optics |
