Selecting an achromatic lens for an optical system requires more than matching the focal length and diameter. Glass combination, design wavelength, surface quality and coating specifications all affect the final optical performance.
At Star Optic, we manufacture achromatic lenses using different optical glass combinations to meet the requirements of imaging systems, fluorescence microscopes, optical inspection equipment and spectroscopic instruments.
Our standard DBTD series covers positive and negative focal lengths, with 12.7 mm and 25.4 mm diameter options. We also provide custom optical design based on customer requirements, including Zemax design, wavelength-specific configurations and optical coating solutions.
An achromatic lens, also known as an achromatic doublet lens, consists of two optical elements made from glasses with different refractive and dispersion properties. Typically, one element has positive optical power and the other has negative optical power. The two elements are cemented together to reduce chromatic aberration.
Compared with a conventional single-element lens, an achromatic doublet provides better control of color focusing, making it suitable for optical systems where image clarity and focusing consistency are important.
At Star Optic, our achromatic lenses are used in a range of optical applications, including:
- Fluorescence Microscopy: Supporting imaging systems that require controlled focusing across specified wavelengths.
- Image Relay Systems: Providing optical components for transferring images between different optical assemblies.
- Optical Inspection Equipment: Suitable for imaging and measurement systems requiring consistent optical performance.
- Spectroscopy Systems: Used in optical assemblies designed for specific wavelength ranges.
- Laser Optical Systems: Available with focal lengths and coating configurations matched to the working wavelength.
For applications involving focusing or collimated light, the lens orientation should also be considered during system assembly. Our team can provide optical configuration recommendations according to the application.
Glass selection is one of the key considerations when designing an achromatic lens. Different glass combinations provide different refractive index and dispersion characteristics, which directly influence the lens design and chromatic correction.
Star Optic offers achromatic doublets using several optical glass combinations, including:
| Glass Combination | Typical Selection Consideration |
| N-BaF10 + N-SF10 | Optical design requiring a specific combination of refractive index and dispersion |
| K9 + H-ZF1 | General achromatic optical designs |
| K9 + H-ZF2 | Achromatic designs requiring a different glass dispersion combination |
| H-ZBaF52 + H-ZF4 | Specialized negative focal length achromatic lens designs in the listed series |
The right combination should be determined by the required focal length, design wavelength and optical correction targets rather than material names alone.
For custom projects, Star Optic can evaluate the glass combination through Zemax optical design according to the customer's wavelength and system requirements. This helps ensure that the selected materials are suitable for the intended optical configuration.
Design wavelength directly affects the optical performance expected from an achromatic lens. A lens designed for visible light may not provide the same correction performance when used at a different wavelength.
Before selecting or customizing an achromatic lens, customers should confirm the following information:
- Working wavelength or wavelength range.
- Required focal length.
- Lens diameter and mechanical dimensions.
- Expected optical performance and application.
- Coating wavelength and transmission requirements.
At Star Optic, we can use Zemax to design and optimize achromatic lenses according to customer-specified wavelengths. For projects with special optical requirements, customers can provide their optical drawings or system parameters for evaluation.
Our standard products are supplied with MgF2 coating at 550 nm, as listed in the product specifications. Other AR coating wavelengths can be discussed for applications requiring different operating conditions.
Focal length and diameter should be selected according to the optical system layout, working distance and available installation space.
Star Optic's standard DBTD series includes positive focal lengths from 25 mm to 150 mm, with diameters of 12.7 mm and 25.4 mm. Negative focal length options are also available in the listed specifications.
For practical selection:
- 25–40 mm focal length: Consider for compact optical assemblies with shorter focal length requirements.
- 50–75 mm focal length: Suitable for optical systems requiring intermediate focal lengths.
- 100–150 mm focal length: Consider for assemblies requiring longer focal lengths and corresponding mechanical spacing.
- Negative focal lengths: Available for optical designs requiring diverging optical power, subject to system configuration.
The diameter should also match the required clear aperture and mechanical mounting dimensions. A larger diameter may be necessary when the optical system requires a larger beam or more installation clearance.
The following table lists our standard DBTD achromatic lens specifications.
| Model | Material | F (mm) | D (mm) | Tc (mm) | Te (mm) | R1 (mm) | R2 (mm) | R3 (mm) | Coating |
| DBTD12.7F25 | N-BaF10+N-SF10 | 25 | 12.7 | 6.3 | 4.9 | 17.27 | 10.99 | 107.03 | MgF2 @ 550nm |
| DBTD12.7F30 | K9+H-ZF1 | 30 | 12.7 | 5.0 | 3.4 | 17.86 | 13.53 | 44.17 | MgF2 @ 550nm |
| DBTD12.7F40 | K9+H-ZF2 | 40 | 12.7 | 5.1 | 3.8 | 24.77 | 18.01 | 51.17 | MgF2 @ 550nm |
| DBTD12.7F50 | K9+H-ZF2 | 50 | 12.7 | 5.0 | 4.0 | 30.73 | 22.32 | 64.75 | MgF2 @ 550nm |
| DBTD12.7F60 | K9+H-ZF2 | 60 | 12.7 | 5.0 | 4.2 | 36.51 | 21.33 | 78.35 | MgF2 @ 550nm |
| DBTD12.7F75 | K9+H-ZF1 | 75 | 12.7 | 4.0 | 3.4 | 41.30 | 33.96 | 137.09 | MgF2 @ 550nm |
| DBTD25.4F75 | K9+H-ZF2 | 75 | 25.4 | 9.5 | 6.9 | 46.44 | 33.77 | 95.94 | MgF2 @ 550nm |
| DBTD25.4F100 | K9+H-ZF2 | 100 | 25.4 | 8.5 | 6.5 | 61.47 | 44.64 | 129.94 | MgF2 @ 550nm |
| DBTD25.4F125 | K9+H-ZF2 | 125 | 25.4 | 8.4 | 6.8 | 76.28 | 54.55 | 162.43 | MgF2 @ 550nm |
| DBTD25.4F150 | K9+H-ZF2 | 150 | 25.4 | 7.9 | 6.6 | 91.37 | 66.21 | 197.71 | MgF2 @ 550nm |
| DBTD12.7F-25 | H-ZBaF52+H-ZF4 | -25 | 12.7 | 4.6 | 5.9 | 17.75 | 12.17 | 109.75 | MgF2 @ 550nm |
| DBTD12.7F-40 | H-ZBaF52+H-ZF4 | -40 | 12.7 | 8.5 | 9.3 | 27.82 | 19.65 | 201.68 | MgF2 @ 550nm |
| DBTD12.7F-50 | H-ZBaF52+H-ZF4 | -50 | 25.4 | 6.6 | 9.3 | 35.51 | 24.58 | 217.99 | MgF2 @ 550nm |
Note: F = focal length, D = diameter, Tc = center thickness, Te = edge thickness, and R1/R2/R3 = surface radii as specified in the product drawings. All dimensions are in millimeters.
These standard specifications provide a starting point for optical system selection. If your required focal length or diameter is not listed, customized configurations can be discussed with our engineering team.
For optical equipment manufacturers and engineering teams, confirming the complete lens specifications before production helps reduce compatibility issues during assembly and testing.
Star Optic provides the following standard achromatic lens specifications:
| Parameter | Specification |
| Material | Optical Glass |
| Design Wavelength | According to Customer Requirements |
| Diameter Tolerance | +0/-0.2 mm |
| Thickness Tolerance | ±0.2 mm |
| Surface Quality | 60/40 |
| Power (@633nm) | 3 fringes |
| Irregularity (@633nm) | 0.5 fringe |
| Centration | <3 arcmin |
| Focal Length Tolerance | ±2% |
| Clear Aperture | >90% |
| Chamfer | Protective, <0.5 mm * 45° |
| Coating | Uncoated, AR, HR, PR, etc. |
These are the listed standard specifications. Different tolerances and optical performance requirements can be evaluated for customized projects.
For procurement, we recommend confirming the focal length tolerance, clear aperture, surface quality and coating wavelength together rather than checking each parameter separately.
This is particularly important for optical assemblies where the achromatic lens needs to match other components without additional mechanical or optical adjustments.
The coating should be selected according to the actual working wavelength and transmission requirements of the optical system.
For general applications where surface reflection is acceptable, an uncoated lens may be sufficient. For systems requiring higher transmission and reduced reflection, an anti-reflection (AR) coating is a more suitable option.
Star Optic's standard DBTD series lists MgF2 coating at 550 nm. If your application operates at another wavelength, we can discuss customized AR coating solutions according to the required operating band.
Other available coating options include:
- AR Coating: For applications requiring reduced surface reflection.
- HR Coating: For optical systems requiring high reflectivity at specified wavelengths.
- PR Coating: For applications requiring controlled partial reflection.
- Uncoated: For projects where coating is not required.
When requesting a quotation, please specify the working wavelength, required coating type and whether the coating is needed on one or both external surfaces. This information helps us evaluate the appropriate coating configuration.
Standard achromatic lenses may not meet every optical system requirement. For OEM equipment manufacturers and optical system integrators, focal length, glass combination, wavelength and mechanical dimensions often need to be adjusted to match the complete assembly.
Star Optic supports custom achromatic lens development based on customer drawings, samples or optical design requirements.
Our customization services include:
- Zemax Optical Design: Lens design and optimization according to specified design wavelengths and optical requirements.
- Custom Glass Combinations: Selection of positive and negative optical glass elements based on the design.
- Focal Length and Diameter: Customized optical dimensions for different system configurations.
- Optical Coatings: AR, HR and PR coating options according to specified wavelengths.
- Mounting Holders: Lens holders can be provided to support installation and alignment adjustments.
For projects involving special optical performance requirements, we recommend providing the design wavelength, target focal length, lens diameter and available installation space at the quotation stage.
This allows our team to evaluate the optical design before confirming the manufacturing specifications.
Selecting an optical lens supplier involves more than comparing standard dimensions and prices. Material selection, manufacturing precision, coating requirements and customization support all affect whether the final component can meet your equipment requirements.
At Star Optic, we provide optical components for different industrial and precision optical applications, with support covering optical design, manufacturing, inspection and coating.
Optical Design Support
We support Zemax-based achromatic lens design according to customer requirements, including specified wavelengths and focal lengths. This is particularly useful for projects that cannot directly use standard catalog specifications.
Multiple Glass Combinations
Our DBTD series includes different optical glass combinations, such as N-BaF10 + N-SF10, K9 + H-ZF1, K9 + H-ZF2 and H-ZBaF52 + H-ZF4.
Precision Manufacturing and Inspection
Our optical manufacturing capabilities include grinding, polishing, centering and coating. Optical components can be inspected using precision measurement equipment, including interferometers and spectrometers.
Flexible Coating Solutions
We provide different coating options, including AR, HR and PR, with wavelength requirements confirmed according to the customer's application.
Standard and Customized Products
Customers can select from our standard DBTD series or request customized focal lengths, diameters, glass combinations and mounting holders.
Whether you are developing an imaging instrument, upgrading an optical assembly or sourcing achromatic lenses for regular production, Star Optic can work with your technical team to identify a suitable solution.
Contact Star Optic with your optical drawings or technical requirements to discuss achromatic lens design, manufacturing and quotation.
An achromatic lens typically consists of two cemented optical elements with different dispersion properties to reduce chromatic aberration. A double convex lens is a single optical element with two convex surfaces. The two designs serve different optical requirements.
An achromatic doublet lens consists of two optical glass elements, generally one positive and one negative, cemented together. It is designed to reduce chromatic aberration at selected wavelengths.
The focal length should match the required object distance, image distance and optical system configuration. You should also consider lens diameter, working wavelength and available installation space.
Yes. Star Optic supports Zemax-based optical design and customized achromatic lenses according to customer-specified design wavelengths and optical requirements.
Yes. We provide AR coating options, including standard MgF2 coating at 550 nm and customized coating solutions according to the required working wavelength.
Yes. Mounting holders can be provided for lens installation and alignment adjustments. Please share your mechanical dimensions and assembly requirements when requesting a quotation.
