|Diameter Tolerance||+0.0/-0.2 mm|
|Thickness||3 mm||5 mm||8 mm|
|Center Thickness Tolerance||±0.4 mm|
|Material||UV Fused Silica|
|Surface Flatness||λ/8 @ 633 nm Over the Clear Aperture|
|Wedge||30 ± 10 arcmin|
|Surface Quality||20-10 (Scratch-Dig)|
|Front Surface Coating||None|
|Back Surface Coating||Broadband AR Coating|
R<1.0% Average within Wavelength Range
|Clear Aperture||90% of the Diameter|
- UV Fused Silica Substrate
- Ø1/2", Ø1", and Ø2" Sizes
- Back Surface AR Coated to Minimize Ghosting
- 0.5° Wedged to Eliminate Interference Fringes
These beam samplers utilize the Fresnel reflection from an uncoated optical surface (indicated on the edge of the optic as shown on the Drawing tab) to pick off 1-10% of an incident beam, depending on the incident light's polarization. With a 45° angle of incidence and a P-Polarized light field, the beamsplitter will provide approximately 1% reflection, while an S-Polarized light field will provide approximately 10% reflection. See the Graphs tab for detailed plots of the reflectivity as a function of polarization and angle of incidence.
These laser-quality beamsplitters are typically used for monitoring applications where optical losses and wavefront distortions of the transmitted beam need to be kept to a minimum. The back surface is wedged to eliminate internal fringes and AR coated to minimize ghosting.
These beam samplers are fabricated from UV fused silica. They are recommended for applications that require minimal wavefront distortion over a larger operating temperature range. In addition, UV fused silica exhibits virtually no laser-induced fluorescence (as measured at 193 nm), making it an ideal choice for applications from the UV to the near IR.
Each UV Fused Silica Beam Sampler is available with one of the following broadband AR coatings: 250-420 nm (Designated with -UV), 350-700 nm (Designated with -A), 650-1050 nm (Designated as -B), or 1050-1620 nm (Designated as -C). These high-performance multilayer AR coatings are designed for angles of incidence between 0 and 30 degrees (0.5 NA). The plot shown below indicates the performance of the standard coatings in this family as a function of wavelength. Broadband coatings have a typical absorption of 0.25%, which is not shown in the reflectivity plots.