BiConvex Lenses, φ20 mm, Focal Distance: 20 mm, Back Focus : 17 mm

[Features]
- This optical lens having positive focal length is mainly used for magnification of image, light condensing, and relay optical system.
- Made of quart, this product offers high transmittance in all regions from ultraviolet region to infra red ray wavelength region（approx. 900nm).
- Its low thermal expansion coefficient ensures excellent heat resistance.
[Specifications]
- Outer diameter (φmm): 20
- Focus distance (mm): 20
- Bag focus (mm): 17
- Medium thickness (mm): 8.2
- Material: Synthetic quartz
- Design wavelength: 587.6nm
- Refractive index: 1.45850/nd
- Chamfer (45°): 0.2 - 0.5mm
- Tolerance range Outer diameter: φ+0/-0.1mm
- Tolerance range Center thickness: ±0.2mm
- Tolerance range Focal length: ±2％
- Tolerance range Surface quality: MIL60-40
- Tolerance range Eccentricity: within 3 minutes (3')