General Comments on Manufacturing Limits

This represents a general list of soft limits and is intended for reference only.

As requirements move closer to a min or max is shown the more challenging the part will be.

Certain combinations may not be possible – Choosing Max Sag and Min Diameter on concave surfaces for example.

Interferometric testing of aspheres is extremely case-specific. The slower the onset of departure, the more likely interferometric testing is possible.

During manufacturing, the lens is oversized in diameter. Be aware, forms well behaved within clear aperture may turn exotic or undefined just beyond the final diameter.

Asphere Manufacturing Limits

General Comments on Manufacturing Limits
Based on Form Error Tolerance

Form Error > 2μm Lower Resolution Profilometry (2-D)¹

wdt_IDAttributeMinimumMaximum
1Diameter (mm)³3250
2Local Radius (mm)-13 (Concave)
3Sag (mm)025²,⁴
4Departure (mm)0.0021
5Included Angle (°)0120+⁵

Form Error 0.5 – 2μm Higher Resolution Profilometry (2-D)¹

wdt_IDAttributeMinimumMaximum
1Diameter (mm)33250
2Local Radius (mm)-12 (Concave)
3Sag (mm)025²
4Departure (mm)0.0120
5Included Angle (°)0150

Form Error < 0.5μm Interferometry with Stitching (3-D)

wdt_IDAttributeMinimumMaximum
1Diameter (mm)3250
2Local Radius (mm)-8 (Concave)
3Sag (mm)050²
4Departure (mm)0.0120
5Included Angle (°)0120
  1. Typical metrology is Zygo MetroPro plots for interferometry
  2. For concave surfaces the maximum may be smaller, limited by tool clearance first. Short radii have lower maximums
  3. Larger diameters can be accommodated using multiscan fusion
  4. Total sag allowed is a function of diameter, determined by fringe resolution of the interferometer
  5. Very basic forms (paraboloid, ellipsoid) can have higher included angles

For more detailed information on any attribute, please contact sales@optimaxsi.com.