Specifications:
| Type | Plano-concave Lens (Circular) | Substrate Material | Fused Silica |
| Diameter | 25.4(+0.0/-0.1)mm | Edge Thickness | 4.0(±0.2)mm |
| Clear Aperture | >90% | Effective Focal Length (EFL) | -250.0mm |
| Flatness | <λ/10 | Surface Quality | 20/10 S/D |
| Chamfer | <0.3mmx45° | Coating | 700-900nm AR Coating |
| GDD | ±10fs^2 | Centering | <3 arcmin |
| Laser Induced Damage Threshold | >2J/cm2@800nm, 100ps, 100Hz |
This is Shalom EO's 2128-027 ultrafast femtosecond plano-concave thin lens, with 700-900nm AR Coating and a -250 mm negative focal length, designed for beam expansion of 700–900 nm wavelength Ti:Sapphire femtosecond ultrashort pulsed lasers. The 2128-027 lens module is a thin defocusing PCV lens made of a fused silica substrate, with a diameter of 25.4 mm and a small edge thickness of 4 mm, contributing to a low group delay dispersion (GDD) of ±10 fs2.