Spherical Optics

Curved surfaces can come in various shapes: spherical, aspherical and cylindrical.

The simplest shape is the spherical one which has a round cross section and is essentially a part of a ball. The location where the ball is truncated determines the so-called surface sag. 
Spherical surfaces are characterized by their origin ball radius. This radius is known as the radius of curvature. The sag of the surface can be calculated using the element outer diameter and its radius of curvature.

Spherical optics can be a substrate with a single polished surface like in the case of spherical mirrors, or with two polished surfaces like in lenses.


Pro-Log Optics works to provide you the exact optics needed for your application. In our portfolio you can find among others:

  • Low cost lenses from Chinese materials.
  • High volume, low cost Polymer lenses.
  • Micro lenses down to 0.2 mm diameter.
  • High quality lenses with high LDT values for laser applications.

We welcome you to work closely with our engineers on your optical need. 
We bring long experience and extensive know-how in the field. We will help you in finding the most cost-effective solution to your optical demand.

Our general specification for spherical optics is as written in the table below. Tighter demands can be considered as well.

Commercial Precision Laser Limit
Diameter Accuracy (mm) +0/-0.1 +0/-0.025 +0/-0.01 +0/-0.005
Center Thickness (mm) ±0.150 ± 0.050 ± 0.010 ± 0.005
Centration (ETV, mm) 0.05 0.015 0.007 0.003
Cosmetic Quality (S/D) 60-40 40-20 10-5 5-2
Surface Figure (PTV, 633nm) λ/2 λ/5 λ/10 λ/100
Surface Roughness (rms, Å) 50 20 5 0.4
Radius accuracy (fringes, 633 nm) 10 5 3 0.5