Article Index

  • Sensitivity to tolerances is a well-known problem in optical design.
  • CAXCAD allow user to reduce general tolerance sensitivity to improve the manufacturability of the optimized lens
  • The SSN2 is as the  “sensitivity” parameter to the merit function.

The Lens Layout 


This is a singlet with conic and even asphere and spot size has been optimized


 Open the High Yield SSN2 sample file 

We use 10 rays to control the spot size

We can find the High Yield item with SSN2 in the Merit Function.

The SSN2 for surface 2 shows that 0.1499 value and it is biggest one, the zero value from SSN2 is our High Yield tagret.

NOTE: The range of SSN2 values is from 0 to 1, with smaller numbers representing less sensitive surfaces.

DLS Optimization with SSN2 

The shapes of lens show that both of the surfaces get the nearly power. 

The SSN2 for surface 2 and surface 3 are both good.

 We can also decrease the weight to get better performance.

The SSN2 can also work with global optimization.

The Merit Function with new SSN2 weight 

We got the same Sensitivity to tolerances, but better spot size performance