Using our advertising package , you can display your logo, further below your product description, and these will been seen by many photonics professionals.
Click here to get more.
You are a not yet listed supplier? Get your entry!
Find more supplier details at the end of this encyclopedia article , or go to our
Author: the photonics expert Dr. Rüdiger Paschotta
An axicon (also called axicon lens) is an optical device similar to a lens, where however one has a conical rather than curved surface. Generally, one side is conical, with the tip looking outwards, and the other surface is flat (plano-convex axicon). In most cases, the transverse cross-section is a circle, as for an ordinary lens. The inclination angle of the surface (called the axicon angle) does not change with increasing distance from the optical axis, while it would continuously change for an ordinary lens. Refraction thus leads to a constant ray deflection angle within a range of input ray positions.
Figure 1 shows a ray tracing simulation for an axicon with parallel incident light. For monochromatic light, for example, one of course obtains interference effects, creating a ring structure, in the region where the different contributions of reflected light overlap.
Figure 1:
Ray tracing simulation for an axicon with parallel incident light.Axicons may be considered as specialty lenses (conical lenses); after all, their outer shape and the typical way of mounting is similar as for lenses. Alternatively, axicons are called conical prisms.
One often specifies the apex angle of an axicon; this is 180° minus twice the above-mentioned axicon angle. Axicons with a wide range of apex angles are available as stock optics, e.g. with 90° but also with much larger angles such as 160°. In the form of custom optics, a wider range of parameters is possible.
Just as other lenses, axicons are available in uncoated forms, but are often delivered with anti-reflection coatings for certain spectral regions. They can be made from various optical materials; mostly, one uses common optical glasses such as fused silica.
There are also fiber axicon lenses, where near a fiber end the fiber diameter is rapidly reduced down essentially to zero. Such fiber axicon lenses can be used for coupling light into very small waveguides of photonic integrated circuits, for example.
For some applications, one requires a ring-shaped pattern as obtained in a sufficiently large distance after an axicon illuminated with parallel light.
Figure 2:
Beam profile in a distance of 2 mm behind an axicon, illuminated with a Gaussian laser beam.A precision-polished axicon can also be used for generating an approximation of a Bessel beam &#; a kind of non-diffracting beam &#; from an ordinary input laser beam, typically a Gaussian beam. This works for the above-mentioned overlap region. In that region, one obtains an annular intensity profile, as shown in Figure 2, which is based on numerical beam propagation. Figure 3 shows that for over a range of distances, the beam intensity pattern stays quite similar, just as if there were no diffraction. Later on, however, the optical energy spreads out more and more.
Bessel beams are used for certain measurement purposes, for example.
Figure 3:
Beam evolution after an axicon, illuminated with a Gaussian laser beam.Axicons are also used in various other applications, for example in the context of laser material processing, atom traps and optical tweezers, optical coherence tomography, for medical instruments in eye surgery, or as parts of certain beam expanders and telescopes.
Encyclopedia articles:
Here you can submit questions and comments. As far as they get accepted by the author, they will appear above this paragraph together with the author&#;s answer. The author will decide on acceptance based on certain criteria. Essentially, the issue must be of sufficiently broad interest.
Please do not enter personal data here. (See also our privacy declaration.) If you wish to receive personal feedback or consultancy from the author, please contact him, e.g. via .
Your question or comment:
Spam check:
(Please enter the sum of thirteen and three in the form of digits!)
By submitting the information, you give your consent to the potential publication of your inputs on our website according to our rules. (If you later retract your consent, we will delete those inputs.) As your inputs are first reviewed by the author, they may be published with some delay.
In contrast to aspheric lenses, the shape of an axicon resembles a cone. Due to the conical shape of the axicon lens so-called bessel beams, ring-shaped beam profiles, can be generated. The diameter of the ring beam depends on the axicon angle and decreases as the distance between the axicon and image plane grows. The ring width remains constant.
The axicon is primarily used in the field of beam shaping and in various laser applications. A particular use is also the generation of non-diffractive Bessel-like beams. An area with almost constant intensity distribution, the length of which is defined by the angle and diameter of the axicon lens, is of interest here. Bessel beams are non-diffractive and ideal for applications in medicine, research, in measuring technology and for adjustments. Specifically, they find use e.g. in optical tweezers and in light sheet [fluorescence microscopy}(/en/solutions/applications/life-science/fluorescence-microscopy/).
In combination with other axicons or lenses, various beam profiles can be generated, such as collimated ring beams and variable ring-shaped focal points.
The optical effect in combination with a laser beam expander, a lens or a second axicon is shown below.
Optical effect of an axicon in combination with other optical elements for generating Bessel beams
1. The illumination of the axicon lens is optimized by combining it with a laser beam expander. This makes it possible to vary the length of the generated Bessel beam.
2. The diameter of the generated ring focus is defined by the focal length of the lens used. The generation of ring-shaped foci is used in material processing and in eye surgery, for example.2. The diameter of the generated ring focus is defined by the focal length of the lens used. The generation of ring-shaped foci is used in material processing and in eye surgery, for example.
3. A collimated ring-shaped beam is generated by combining two axicons with the same angle. The diameter of the beam changes with the distance between both elements.3. A collimated ring-shaped beam is generated by combining two axicons with the same angle. The diameter of the beam changes with the distance between both elements.
4. This setup enables the focal width of an asphere to be reduced, whereby focusing below the diffraction limit is possible. This is made possible by the ring-shaped illumination of the asphere.
5. The setup shown is suitable to improve the focus quality of a spherical lens. Through what is known as zonal decompensation, the ring-shaped illumination of individual zones of the lens, effects of spherical aberration are eliminated and focusing is thus improved.5. The setup shown is suitable to improve the focus quality of a spherical lens. Through what is known as zonal decompensation, the ring-shaped illumination of individual zones of the lens, effects of spherical aberration are eliminated and focusing is thus improved.
6. This setup is used to generate variable ring foci. By moving the second axicon, the diameter of the ring focus can be adjusted.6. This setup is used to generate variable ring foci. By moving the second axicon, the diameter of the ring focus can be adjusted.
Based on high-end technologies asphericon manufactures axicons with surface shape deviations (RMSi) of up to 0.04 µm. Together with our customers, we develop and produce suitable solutions from a large selection of optical glasses, from prototypes to series production. Take advantage of individual custom solutions,optical coatings or the innovative variety of stocked axicons from the StockOptics product line. The latter are available with surface deviations of RMSi &#; 0.07 µm in our webshop.
In order to simplify alignment and achieve optimal imaging results, axicons from asphericon can also be precisely aligned using specially developed mounts. In addition, the mounted axicons, like all mounted optics from asphericon, can be easily screwed to other elements via a metric fine thread. Learn more about the benefits of asphericons mounted lenses.
Thanks to their conical shape, all axicons can be used in a wide variety of applications.
asphericon manufactures according to RoHS and REACH regulations which is guaranteed by appropriate certificates.
&#; Download RoHS Declaration
&#; Download REACH Declaration
Discover our selection of high-precision Axicons.
Based on your individual specifications, our optical designers develop the right axicon - Thanks to the latest production and measuring technology, a high level of precision is guaranteed. Coated or uncoated, as an unmounted optical component or mounted axicon, almost all optically effective materials with accuracies of up to 200 nm global form errors (irregularities) or 40 nm RMSi are suitable for production using specially developed CNC-controlled grinding and polishing processes. You also benefit from the following specifications:
Superior quality
-Surfaces of the highest quality
As a customized solution, asphericon produces convex and concave axicons with irregularities RMSi &#; 0.05 µm. According to the requirements of our customers, we produce prototypes, small series and series.
Unique technology
-Precision that exceeds standards
asphericon not only impresses with the most modern manufacturing technologies, but also with unique high-end finishing processes, ultra-precise measurement options and high-quality coating technologies.
Complementary Services
-Measurement, coating and optical mount
We produce optical coatings to suit your individual requirements, complete your axicons with high-quality frames and/or characterize them.
&#; Download Production capabilities
Speak to our team
Speak to our team
Sales Team Jena
:
:
Discover our exclusive selection of off-the-shelf a|Axicons. They are convincing with surface form deviation of RMSi &#;0.07 µm and the following specifications:
Off-the-shelf delivery
-Fast availability and short delivery times
The advantages of precision-manufactured axicons combined with the cost advantages of serial production: Axicons from the StockOptics line can easily be ordered directly from stock via our webshop.
High-quality mounts
Link to Hongsheng
-Engraved with lens specifications
Perfectly aligned, selected a|Axicons are also available with high-precision mounts and a decentration of < 10 µm. Mounts labeled with the lens specifications allow convenient handling in a wide range of applications.
High-quality coatings
-Standardized or individual
asphericon manufactured optical coatings in the spectral range from UV to the near infrared range, from anti-reflective coatings to wavelength-specific filter layers, to suit your individual requirements.
RMSi [nm]
Diameter [mm]
λDesign [nm]
Material
Coating
Product CodeRMSi [nm]Scratch-DigDiameter [mm]Angle [degree]Edge Thickness [mm]λDesign [nm]MaterialCoatingPrice uncoatedPrice coatedXFL25-005-U-U-.40.55.Fused SilicaA / B / C / X552..00Quote
XFL25-010-U-U-.41.05.Fused SilicaA / B / C / X552..00Quote
XFL25-020-U-U-.42.05.Fused SilicaA / B / C / X552..00Quote
XFL25-050-U-U-.45.05.Fused SilicaA / B / C / X552..00Quote
XFL25-100-U-U-.410.05.Fused SilicaA / B / C / X552..00Quote
XFL25-200-U-U-.420.05.Fused SilicaA / B / C / X552..00Quote
XFL50-005-U-U-.80.58.Fused SilicaA / B / C / X896..00Quote
XFL50-020-U-U-.82.08.Fused SilicaA / B / C / X896..00Quote
XFL50-050-U-U-.85.08.Fused SilicaA / B / C / X896..00Quote
XFL50-100-U-U-.810.08.Fused SilicaA / B / C / X896..00Quote
XFL50-200-U-U-.820.08.Fused SilicaA / B / C / X896..00Quote
Prices are valid per piece and in USD. Sales only to commercial customers. All prices are exclusive of VAT.
RMSi [nm]
Diameter [mm]
λDesign [nm]
Material
Coating
Product CodeRMSi [nm]Scratch-DigDiameter [mm]Angle [degree]Edge Thickness [mm]λDesign [nm]MaterialCoatingPrice uncoatedPrice coatedXFM25-005-U-U-.40.55.Fused SilicaA / B / C / X552..00Quote
XFM25-010-U-U-.41.05.Fused SilicaA / B / C / X552..00Quote
XFM25-020-U-U-.42.05.Fused SilicaA / B / C / X552..00Quote
XFM25-050-U-U-.45.05.Fused SilicaA / B / C / X552..00Quote
XFM25-100-U-U-.410.05.Fused SilicaA / B / C / X552..00Quote
XFM25-200-U-U-.420.05.Fused SilicaA / B / C / X552..00Quote
Prices are valid per piece and in USD. Sales only to commercial customers. All prices are exclusive of VAT.
Coating options*
AR-CoatingsA: RMAX <1.0%, 532 nm, AOI=0°B: RMAX <1.0%, RAVG &#;0.4%, 632-780 nm, AOI=0°C: RMAX <1.0%, nm, AOI=0°X: RMAX <1.0%, 355 nm, AOI=0°&#; StockOptics Catalog Europe
Custom Axicons
StockOptics AxiconsStockOptics Axicons
Precise mounted axiconsPrecise mounted axicons
Speak to our team
Speak to our team
Sales Team Jena
:
:
Always the latest news from asphericon