General Comments on Tolerancing Limits
This represents a general list of soft limits and is intended for reference only.
Reducing tolerance range increases costs.
Optimax advises a close consideration of budget (tolerance, delivery, or dollar) versus need to be made prior to choosing any value below.
Robust sensitivity analyses will help yield the most cost-effective tolerancing.
Tolerancing Limits for Aspheric Surfaces
|wdt_ID||Attribute||Asphere Tolerancing Limit|
|1||Glass Quality (nd, vd)||Melt Rebalanced and Controlled|
|2||Diameter (mm)||+0, -0.010|
|3||Center Thickness (mm)⁶||± 0.010|
|4||Sag – Concave (mm)||± 0.010|
|6||Vertex Radius⁸||± 0.1% or 3 HeNe fringes⁹|
|7||Irregularity – Interferometry (HeNe fringes)¹⁰||0.11¹¹|
|8||Irregularity – Profilometry (μm)¹⁰||± 0.5|
|9||Wedge Lens – ETD (mm)||0.002¹²|
|10||Bevels – Face Width @ 45° (mm)¹³||± 0.05|
|11||Scratch – Dig (MIL-PRF-13830B)¹⁴||10 – 5|
|12||Surface Roughness (Å RMS)¹⁵||10|
- This is for the most well-behaved materials. More difficult materials (CaF2, Ohara S-FPL, etc) will need larger tolerance ranges
- Of full aperture (FA)
- In addition to irregularity
- Whichever is correspondingly larger over the clear aperture
- A vertex radius tolerance is required in addition to irregularity
- As geometry requirements move closer to a min or max shown the less likely this is possible
- This specification is extremely tight and expensive. For a more economical limit, please consider using 0.005mm.
- Subject to measurement uncertainty
- Crystals and reflective materials will receive 40W inspection
- This represents lowest values obtained. Actual values for crystalline, especially polycrystalline materials, will be higher.