UV Fused Silica Plano-Concave Lenses, Uncoated

Common Specifications
Lens Shape	Plano/Concave
Substrate Material	UV Grade Fused Silica
Wavelength Range	185 nm - 2.1 μm
Diameters Available	6 mm, 8 mm, 1/2", or 1"
Diameter Tolerance	+0.00 mm / -0.10 mm
Thickness Tolerance	±0.1 mm
Focal Length Tolerance	±1%
Design Wavelength	588 nm
Index of Refraction (@ Design λ)	1.460
Surface Quality	40-20 Scratch-Dig
Surface Flatness (Plano Side)	λ/2
Spherical Surface Power (Concave Side)a	3λ/2
Surface Irregularity (Peak to Valley)	λ/4
Clear Aperture	>90% of Diameter
Centration	≤3 arcmin

• Much like surface flatness for flat optics, spherical surface power is a measure of the deviation between the surface of the curved optic and a calibrated reference gauge, typically for a 633 nm source, unless otherwise stated. This specification is also commonly referred to as surface fit.

Zemax Files
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Features

• 4 Different Diameters Available: 6 mm, 8 mm, 1/2", or 1"
• Wavelength Range: 185 nm - 2.1 μm (Uncoated)
• Focal Lengths Available from -10.0 to -200.0 mm
• Fabricated from UV Grade Fused Silica
• Form Virtual Images

Thorlabs' UV Grade Fused Silica Plano-Concave lenses are uncoated UV-grade fused silica offers high transmission in the deep UV and 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. In addition, UV fused silica has better homogeneity and a lower coefficient of thermal expansion than N-BK7.

Plano-concave lenses have negative focal lengths, making them useful for a wide range of applications. They are commonly used to diverge a collimated incident beam; in such cases the collimated light source should be incident on the curved surface to minimize spherical aberrations. Plano-concave lenses, which produce virtual images, are used as the entrance optic in Galilean-type beam expanders; this lens provides the desired divergence and then a doublet is used to recollimate the beam. In optical systems, it is common for researchers to choose their optics carefully so that the aberrations introduced by the positive- and negative-focal-length lenses approximately cancel. Still others use these lenses in pairs to increase the effective focal length of a converging lens.

When deciding between a plano-concave lens and a bi-concave lens, both of which cause collimated incident light to diverge, it is usually preferable to choose a plano-concave lens if the desired absolute magnification is either less than 0.2 or greater than 5. Between these two values, bi-concave lenses are generally preferred.

Thorlabs offers these plano-concave lenses in sizes ranging from Ø6 mm to Ø1". Each size is compatible with a multitude of Thorlabs' lens mounts. Please see the Mounting Options tab for details.