One surface of axicon lenses is conical and the other is flat, creating a distinctive lens design. Depending on the location, the collimated light incident on the flat side will either grow into a ring or produce an approximation of the Bessel distribution. As the distance between the axicon lense and the image plane widens, the diameter of this ring also widens. The material's refractive index, the α angle, and the separation between the vertex and the image plane all have a direct bearing on the diameter of the ring. A focused beam with the shape of a ring is produced by combining an axicon lense and a spherical lens.
Axicon lenses are commonly used in telescopic and ophthalmic applications. Alfa Chemistry can create axicon lenses particularly for each client's requirements. In our cutting-edge metrology lab, our highly qualified personnel test each product to make sure it complies with requirements. Please get in touch with our technical sales team for further details on your custom axicon lens requirements.
Our Capabilities
To satisfy unique customer needs, Alfa Chemistry can produce axicon lenses in a range of sizes and quality. Depending on whether the tapering surface is convex or concave, axicon lenses are available in positive or negative designs. Typical materials used are UV-fused silica and Schott BK7, but alternatives are available, including zinc selenide for NIR and IR applications. In addition, we can coat lenses for UV, visible, or NIR uses depending on the application and the material utilized.
The manufacturing capabilities shown below may vary depending on the material, so please contact us for further details.
| Diameter | 3 mm·~ 300 mm+ |
| Angle | 0.5° to 20° |
| Surface quality | < 10/5 |
| Surface Figure | < 0.1 fringes |
| Material Options | Schott glass or UVFS |
Coatings
Alfa Chemistry can also apply optical coatings to your axial cone lenses to enhance their transmittance or reduce surface reflection. Anti-reflective (AR) coatings, such as broadband coatings, are a few examples. These coatings are frequently used to enhance performance at particular wavelengths.
Quality Assurance
- On the Starrett AV300 optical instrument, we check the apex angle, a crucial axicon lens parameter.
- Our Zygo Verifire XPZ device measures surface shape error, which is the surface form error of the lens.
- We use a spectrophotometer to evaluate transmission, reflection, and optical density by performing spectral scans at various incidence angles and polarizations.
- Prior to shipping, all custom optics are 100% visually inspected. Our crew is highly trained and capable of checking for scratches and dig marks as small as 10/5, which is crucial for lenses used in laser applications.
Fig 1. Schematic diagram of the axicon lens-based setup. Axicons 1 and 2 are used to create collimated laser ring; Axicon 3 is used to create light with the cone shell geometry. (Yi O. H, et al. 2014)
Typical Applications
- Ophthalmic Applications
When doing laser eye surgery, positive and negative axicon lenses are used to shape the cornea.
- Optical Coherence Tomography (OCT)
At longer depths of focus, axicon lenses can generate images with high lateral resolution.
- Astronomical Applications
In telescopic applications, an axicon lense can produce a deeper depth of focus than a standard spherical lens.
- Other Applications
Atom capture and laser research.
Alfa Chemistry is always looking to expand and work with customers to achieve their specifications, so please feel free to contact our technical sales team for more information and guidance on your enquiry.
Reference
- Yi O. H, et al. (2014)."Phantom Validation of Monte Carlo Modeling for Noncontact Depth Sensitive Fluorescence Measurements in An Epithelial Tissue Model." Journal of Biomedical Optics. 19(8): 85006.