General Comments on Manufacturing 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 Spherical Surfaces
|wdt_ID||Attribute||Sphere Tolerancing Limit|
|1||Glass Quality (nd, vd)||Melt Rebalanced and Controlled|
|2||Diameter (mm)||+0, -0.010|
|3||Center Thickness (mm)⁴||± 0.020|
|4||Sag – Concave (mm)||± 0.010|
|6||Radius (mm)⁶||± 0.0025 or 1 HeNe fringe⁷|
|7||Irregularity (HeNe fringes)⁸||0.05⁹|
|8||Wedge Lens – ETD (mm)||0.002¹⁰|
|9||Bevels – Face Width @ 45° (mm)||± 0.05¹¹|
|10||Scratch – Dig (MIL-PRF-13830B)¹²||<10 – 5|
|11||Surface Roughness (Å RMS)||3¹³˒¹⁴|
- This is for the most well-behaved materials. More difficult materials (CaF2, Ohara S-FPL, etc.) will need larger tolerances ranges.
- Of full aperture (FA)
- In addition to irregularity
- Whichever is correspondingly larger over the clear aperture
- Coverage dependent, stitched or otherwise, and also subject to system error
- 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.
- With scan length and filter appropriate for the selected spatial period.