Thin Ultrafast Lenses (Plano Concave) for Femtosecond Lasers

Femtoline plano concave lenses are lenses with negative focal lengths and very thin thickness, used to diverge or compensate for focusing optics in femtosecond pulsed laser beams. Unlike biconcave lenses, PCV lenses consist of a plano surface and an inwardly curved spherical surface; the two dissimilar surface profiles help to reduce spherical aberration when the absolute conjugate ratio is greater than 5:1. We recommend you to orient the concave side of the PCV lens towards the incoming light to reduce spherical aberration.

Other important specs for ultrafast lenses are their group delay dispersion (GDD) requirement and optical aberrations. To achieve these, ultrafast lenses are always coated with low GDD Ant-reflection coating and processed into thinner thickness, as this makes the dispersion path shorter.

Shalom EO offers off-the-shelf and custom plano concave thin lenses designed for femtosecond ultrashort pulsed lasers. For standard femtoline PCV lenses,  the specifications are ±10fs2 GDD, -1000mm to -30mm focal lengths, 3mm to 6mm edge thickness at 12.7mm or 25.4mm diameters. The lenses are AR-coated to provide high transmission at the wavelengths of interests. In addition, we can also provide plano convex ultrafast thin lenses.

Plano-concave femtoline lenses can be used for the following applications:

• Nonlinear optics
• Pump-probe setups
• Ultrafast spectroscopes

Specifications: