what is a plano-concave lens

A plano-concave lens is a negative lens with a negative focal length, and the parallel beam will diverge after being incident on the plano-concave lens. The outgoing light cannot converge into one point, but it seems to diverge from a virtual image point located in the object space. When the absolute conjugate ratio is greater than 5:1 or less than 5:1, the plano-concave lens reduces spherical aberration and coma. , Distorted negative lens of the best shape. The concave surface of the plano-concave lens should face the object direction, but when used in a high-energy laser system, it should be placed in the opposite direction to reduce the possibility of the remaining reflected light from the surface gathering. Plano-concave lenses are spherical on one side and flat on the other. The middle is also thinner than the sides.

Features of Plano-Concave Lens:

A plano-concave lens has a concave surface and a flat surface with a negative focal length. Usually used for beam collimation, increase (decrease) the focal length, or enlarge (reduce) the image. In order to obtain a smaller spherical aberration, when the incident beam is a collimated beam, the collimated beam should be incident on the concave surface of the plano-concave lens. Plano-concave lenses with negative focal length are often used in imaging or beam collimation applications, and coated lenses are also widely used in visible light and near-infrared applications.

The conventional lens sizes are: Φ12.7mm, Φ25.4mm, Φ50.8mm, and can produce customized biconvex lenses according to customer project requirements.

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Plano-concave lens parameters:

Optional materials: K9, N-BK7, JGS series UV fused silica

Working range: 400 nm-700nm (other bands can be customized)

Design wavelength: 546.1nm (n=1.519)

Focal length tolerance: ±2%

Shape tolerance: +0.0/-0.02mm

Thickness tolerance: ±0.02mm

Curved aperture: 3

Plane flatness (aperture): 1

Surface local aperture: 0.5

Eccentricity: ≤3arcmin

Surface type: λ /4@632.8nm

Surface finish: National standard three, US military standard 60-40

Clear aperture: >90%

Safe beveling: <0.2X45°