• Opto Module

Plane-Concave Lens | BK7 & Fused Silica Optical Lenses

Plane-concave lenses are negative focal length optical components designed to diverge collimated light, expand laser beams, and correct spherical aberrations in optical systems.

Shape Optics Technologies manufactures high-precision plane-concave lenses using optical-grade BK7 and Fused Silica, offering excellent transmission from the UV to NIR spectrum (185–2500 nm). These lenses are produced with tight mechanical tolerances and superior surface quality, making them suitable for laser systems, imaging optics, and scientific instrumentation.

 

Key Features

  • Materials: BK7, Fused Silica

  • Wavelength Range:

    • BK7: 350–2000 nm

    • Fused Silica: 185–2500 nm

  • Dimension Tolerance: +0.0 / −0.1 mm

  • Thickness Tolerance: ±0.1 mm

  • Effective Diameter: >90%

  • Focal Length Tolerance:

    • 5% (Standard)

    • 1% (High Precision)

  • Surface Quality:

    • 40-20 (Standard)

    • 20-10 (High Precision)

  • Surface Flatness: Power λ/2, PV λ/4

  • Centration: <3 arc-min

  • Optical Coating: Custom AR or functional coatings

 

Physical Properties

Property BK7 Fused Silica
Material BK7 Fused Silica
Wavelength Range 350–2000 nm 185–2500 nm
Dimension Tolerance +0.0 / −0.1 mm +0.0 / −0.1 mm
Thickness Tolerance ±0.1 mm ±0.1 mm
Effective Diameter >90% >90%
Focal Length Tolerance 5% / 1% 5% / 1%
Surface Quality 40-20 / 20-10 40-20 / 20-10
Surface Flatness Power λ/2, PV λ/4 Power λ/2, PV λ/4
Centration <3′ <3′
Coating Customizable Customizable

 

Optical Performance

Shape Optics’ plane-concave lenses are engineered to provide:

  • High optical transmission across UV-VIS-NIR bands
  • Low wavefront distortion and minimal aberration
  • Stable beam divergence and beam expansion control
  • Compatibility with high-power and precision optical systems

Custom anti-reflection (AR) and functional coatings are available to optimize performance for specific wavelengths or laser lines.

 

Standard Specifications 

  • Materials: BK7, Fused Silica
  • Surface Quality: up to 20-10
  • Flatness: λ/4 PV
  • Centration: <3′
  • Custom sizes, focal lengths, and coatings available

 

Applications

  • Laser beam expansion and divergence control
  • Imaging and projection systems
  • Optical instrumentation and metrology
  • Scientific research and laboratory optics
  • UV, VIS, and NIR optical systems

 

Manufacturing, Processing & Handling

All plane-concave lenses undergo strict quality inspection, including surface accuracy, centration, and coating verification. Handling and installation guidelines are provided to ensure long-term optical stability and performance.