Customers trust Optimax to create high-quality optics and deliver them fast, and our custom aspheres are no exception. Designing with aspheres reduces the size and weight of your system. Optimax produces aspheres from glass, fused silica, crystals and ceramics for UV, Visible and IR applications using proprietary “grind and shine” techniques for low scatter surfaces.
We’ll walk you through the process, and invite you to visit the Resource Library for technical resources at every step.
Aspheres have one or more optical surfaces of non-constant curvature. They have a wide range of applications and are used to manage aberrations inherent to spherical lens systems, and to reduce system size and weight. Aspheric lenses have enabled a leap forward in capabilities for medical devices and defense and security.
Manufacturing and metrology of complex aspheres is an emerging science for optical fabricators: Optimax leads the way in our investment in cutting edge equipment and testing, research and training, and track record of performance on customer programs.
Specifying an asphere begins with a custom aspheric form, often fit to the Forbes Q Polynomial (Figure 1) or the Even Aspheric Equation (Figure 2). Describing form involves specifying Vertex Radius (I/C). Conic Constant (k) and applicable Aspheric Coefficients (a). Including a Sag Table (Figure 3) provides reference information to check correct data entry for each manufacturing or metrology tool used.
Optimax places tolerances on vertex radius and form error, without tolerances on conic constant or aspheric coefficients. Even aspheric coefficients are preferred.
Need to spec or quote an asphere? Contact us or browse our technical resources:
Figure 1
Figure 2
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Figure 2
[/lgc_column]Looking for the most advanced manufacturing and metrology technology in North America? Optimax utilizes deterministic CNC machine tools for predictable removal rates and adherence to tight tolerances. To control centration, precision tools maintain the optical axis.
Need to spec or quote an asphere? Contact us or browse our technical resources:
Optimax inspects 100% of all optics. Test data is provided with prototype orders.
Our metrology must match the sophistication of our manufacturing technology. Optimax offers state-of-the-art metrology, including surface profilers and interferometers to verify that parts meet the form error specification.
Testing options are form-specific lenses with mild departure from a best-fit sphere that has the highest potential for fractional wave precision.
Based on Form Error Tolerance
Form Error > 2μm Lower Resolution Profilometry (2-D)1 |
||
|---|---|---|
Attribute |
Minimum |
Maximum |
| Diameter (mm) | 3 | 250 |
| Local Radius (mm) | -8 (Concave) | ∞ |
| Sag (mm) | 0 | 502 |
| Departure (mm) | 0.01 | 20 |
| Included Angle (°) | 0 | 120 |
Form Error 0.5 – 2μm Higher Resolution Profilometry (2-D)1 |
||
Attribute |
Minimum |
Maximum |
| Diameter (mm)3 | 3 | 250 |
| Local Radius (mm) | -12 (Concave) | ∞ |
| Sag (mm) | 0 | 252 |
| Departure (mm) | 0.01 | 20 |
| Included Angle (°) | 0 | 150 |
Form Error < 0.5μm Interferometry with Stitching (3-D) |
||
Attribute |
Minimum |
Maximum |
| Diameter (mm)3 | 3 | 250 |
| Local Radius (mm) | -13 (Concave) | ∞ |
| Sag (mm) | 0 | 252,4 |
| Departure (mm) | 0.002 | 1 |
| Included Angle (°) | 0 | 120+5 |
Attribute |
Minimum |
Maximum |
| Diameter | 3mm | 500mm |
| Wavelength | 193nm | 6000nm |
| Use Environment | Vacuum | >95% RH |
| Durability | Moderate abrasion | Severe abrasion |
| Measurement | — | 68°, s, p, average polarization |
| Laser Damage Threshold | — | 1064nm: >30J/cm2@10ns, >1MW/cm2CW |
| Layers | 1 | 200 |
Rod or Arbor |
||
|---|---|---|
Attribute |
Minimum |
Maximum |
| Length (mm) | 3 | 5001 |
| Width (mm) Radius dependent | 2 | < 2x Radius |
| Cylinder Radius (mm) – Convex Only | 2 | 150 |
X-Y |
||
| Attribute | Minimum | Maximum |
| Length (mm) | 3 | 300 |
| Width (mm) | 2 | 300 |
| Cylinder Radius (mm) | 10 | ∞ |
| Concave sag to flat (mm) | 0.1002 | =Radius |
Attribute |
Tolerancing Limit* |
| Diameter (mm) | +0, -0.010 |
| Center Thickness (mm) | ± 0.050 |
| Irregularity – Interferometry (HeNe fringes) |
0.1** |
| Irregularity – Profilometry (μm) | ±1.0 |
| Wedge Lens – ETD (mm) |
TBD |
| Surface Roughness (Å RMS) | 10 |
Attribute |
Minimum |
Maximum |
| Diameter (mm) | 3 | 300 |
| Thickness | 1 | 150 |
| Aspect Ratio1 | 1 | 502 |
Based on Form Error Tolerance
Attribute |
Minimum |
Maximum |
| Diameter (mm) | 3 | 400 |
| Radius (mm) | ±1 | ∞2 |
| Aspect Ratio (Diameter/Center Thickness) | <1:1 | 30:1 |
| Included Angle (°) | 0 | 2103 |
Attribute |
Asphere Tolerancing Limit |
|---|---|
| Glass Quality (nd, vd) | Melt Rebalanced and Controlled |
| Diameter (mm) | +0, -0.010 |
| Center Thickness (mm)6 | ± 0.010 |
| Sag – Concave (mm) | ± 0.010 |
| Clear Aperture | 100%7 |
| Vertex Radius8 | ± 0.1% or 3 HeNe fringes9 |
| Irregularity – Interferometry (HeNe fringes)10 | 0.111 |
| Irregularity – Profilometry (μm)10 | ± 0.5 |
| Wedge Lens – ETD (mm) | 0.00212 |
| Bevels – Face Width @ 45° (mm)13 | ± 0.05 |
| Scratch – Dig (MIL-PRF-13830B)14 | 10 – 5 |
| Surface Roughness (Å RMS)15 | 10 |
Attribute |
Cylinder Tolerancing Limit |
|---|---|
| Glass Quality (nd, vd) | Melt Rebalanced and Controlled |
| Length and width (mm) | +0, -0.020 |
| Center Thickness (mm)3 | ± 0.020 |
| Sag – Concave (mm) | ± 0.020 |
| Clear Aperture | 100%4 |
| Radius5 | ± 0.1% or 3 HeNe fringes6 |
| Irregularity – Interferometry (HeNe fringes)7 | 0.18 |
| Irregularity – Profilometry (μm) | ± 0.5 |
| Plano Axis Wedge – ETD (mm) | 0.00512 |
| Cylinder Axis Decentration – TIR (mm)9 | 0.01010 |
| Axial Twist Angle (arcminutes) | 3 |
| Bevels – Face Width @ 45° (mm)11 | 0/0mm max |
| Scratch – Dig (MIL-PRF-13830B)12 | 10 – 5 |
| Surface Roughness (Å RMS)13 | 5 |
Attribute |
Prism Tolerancing Limit |
|---|---|
| Glass Quality (nd, vd) | Melt Rebalanced and Controlled |
| Diameter (mm) | +0, -0.010 |
| Center Thickness (mm)3 | ± 0.010 |
| Sag – Concave (mm) | ± 0.010 |
| Clear Aperture | 100%4 |
| Power5 | 0.1 HeNe fringes6 |
| Irregularity – Interferometry (HeNe fringes)7 | 0.18 |
| Wedge Prism (window) – ETD (mm)9 | 0.00210 |
| Bevels – Face Width @ 45° (mm)11 | sharp |
| Scratch – Dig (MIL-PRF-13830B)12 | 10 – 5 |
| Surface Roughness (Å RMS)13 | 4 |
Attribute |
Sphere Tolerancing Limit |
|---|---|
| Glass Quality (nd, vd) | Melt Rebalanced and Controlled |
| Diameter (mm) | +0, -0.010 |
| Center Thickness (mm)4 | ± 0.020 |
| Sag – Concave (mm) | ± 0.010 |
| Clear Aperture | 100%5 |
| Radius (mm)6 | ± 0.0025 or 1 HeNe fringe7 |
| Irregularity (HeNe fringes)8 | 0.059 |
| Wedge Lens – ETD (mm) | 0.00210 |
| Bevels – Face Width @ 45° (mm) | ± 0.0511 |
| Scratch – Dig (MIL-PRF-13830B)12 | <10 – 5 |
| Surface Roughness (Å RMS) | 313,14 |
Here are manufacturing limits and tolerances specific to optical aspheres, prisms, cylinders and spheres. For more detailed information on any attribute, please contact sales@optimaxsi.com.
Optimax’s R&D department is continuously looking for ways to improve our fabrication process and produce higher quality optics. Our current research projects are designed to meet future market needs, such as:
For more information please see Optimax Innovation or contact sales@optimaxsi.com.
Recent design methods and software advances make it much easier to design aspheric surfaces that actually work in production and test by considering manufacturability issues at the earliest possible stage in the design process.
Optimax Systems, Inc., a leader in quick delivery prototype optics, has been manufacturing aspheric lenses for more than 20 years. Along the way, we have learned many lessons and provide takeaways for other manufacturers and designers.
As featured in Laser Focus World: Three metrology tools for the measurement of freeform optics are compared: the coordinate measurement machine, a high-accuracy profilometer, and a noncontact optical technique called fringe reflection deflectometry
Optical Society of America: Surface Slope Tolerances This webinar will describe the effects of surface slope errors – concentrating on the “mid spatial frequency” region – on image quality, and will describe methods for determining tolerances for surface slope. Presented by John Rogers, Ph.D., Synopsys Sponsored by Optimax  
What: Precision asphere manufacturing lean cell Capabilities: This will allow us to create rotational symmetric aspheric lenses in production quantities. These types of lenses are used in imaging systems to reduce, size and weight while improving overall system performance. When: Cell will be operational end of
With years of experience perfecting its Lean manufacturing processes, Optimax is uniquely qualified to offer fast, on-time deliveries.
Optimax is the world’s leading rapid delivery manufacturer of custom optical components. Since its founding, Optimax has recognized that industries and institutions need fast deliveries of high quality, precision optics and has invested more than 15 years perfecting highly reliable and effective Lean processes. To learn more about these and other Optimax innovations, please visit About Optimax.
Customers trust Optimax to reliably manufacture their most complex optics on time. In the unlikely event that an expedited delivery is late, Optimax policy is to refund any unearned premium.
Optimax excels at grinding, polishing and coating precision optics quickly and reliably. We can deliver high precision optics in as little as one week.
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