Axicons

Overview
Beam Shape
Prism Guide
Feedback

Common Specifications
Substrate Material	UV Fused Silica^a
Diameter	1" (25.4 mm)
Diameter Tolerance	+0.0 / -0.1 mm
Apex Rounding Diameter (S1)	<1.5 mm
Surface Quality (S1, S2)	40-20 Scratch-Dig
Surface Flatness (S2)	<λ/10 at 633 nm
Surface Deviation (RMS) (S1)	<0.05 µm
Surface Roughness (RMS) (S1)	<6 Å
Clear Aperture (S1, S2)	>90% of Diameter
Edge Thickness	5.0 mm
Edge Thickness Tolerance	+0.1/-0.0 mm
Center Thickness Tolerance	+0.1/-0.0 mm
Angular Tolerance	±0.01°

Click Link for Detailed Specifications on the Substrate Glass

Precision Aspheric Lenses
UV Fused Silica	Unmounted
UV Fused Silica	Mounted
N-BK7 / S-LAH64	Unmounted
N-BK7 / S-LAH64	Mounted
Zinc Selenide	Unmounted
Acylindrical Lenses	Unmounted
Axicons	Unmounted

Click to Enlarge
The diagram above shows the definitions of thicknesses and angles used on this page.

Features

1" Diameter
Six Physical Angles Available: 0.5°, 1.0°, 2.0°, 5.0°, 10.0°, and 20.0°
Offered Uncoated or With an AR Coating for Maximum Transmission

Applications

Laser Drilling/Optical Trepanning
Optical Trapping
Optical Coherence Tomography (OCT)
Corneal Surgery
Telescopes

An axicon, also known as a rotationally symmetric prism, is a lens that features one conical surface and one plano surface. They are commonly used to create a beam with a Bessel intensity profile or a conical, non-diverging beam. When converting a collimated beam into a ring, the plano side of the axicon should face the collimated source.

An axicon deflects light according to Snell's Law, which can be used to find the deflection angle:

where n is the index of refraction of the glass, α is the physical angle of the prism, and ß is the angle the deflected beam creates with the optical axis. Here, the refractive index of air is assumed to be 1. This interaction is illustrated in the reference image to the right. For more information, please see the Beam Shape tab above.

These Ø1" precision-polished axicons are offered with base angles from 0.5° to 20°. These axicons are precisely manufactured from high-quality UV Fused Silica, making them ideally suited for high-power laser applications. Our axicons are offered uncoated or with an antireflection coating deposited on both sides for one of four wavelength ranges: -UV (245 - 400 nm), -A (350 - 700 nm), -B (650 - 1050 nm), or -C (1050 -1700 nm). These coatings reduce surface reflections from the lens to maximize transmission (R_avg < 0.5%). For a custom coating, please contact Tech Support for a quote.

Custom Axicons
Thorlabs' Fused Silica Axicons are manufactured at the production facility in our headquarters in Newton, NJ. Our optics business unit has a wide breadth of manufacturing capabilities that allow us to offer a variety of custom optics for both OEM sales and low quantity one-off orders. Custom physical angles and coatings are available with prices that are comparable to our stock offerings. Utilizing a unique, post-polishing process, we are able to offer Apex Rounding Diameters down to 0.7 mm and Surface Irregularities as low as 55 nm. Please contact Tech Support to inquire about custom orders.

Zemax Files
Click on the red Document icon next to the item numbers below to access the Zemax file download. Our entire Zemax Catalog is also available.

Figure 3: Axicon ray tracing diagram.

Axicon Beam Shape

Figure 4: The photograph above shows the beam of a collimated laser beam after it is transmitted by an axicon.

Axicon Beam with Lens

Figure 5: The photograph above shows the beam from
Figure 1 if a plano-convex lens is placed after the axicon.

Axicon Beams

Bessel Beam: Non-Diffracting
Ring-Shaped Beam: Ideal for Laser Drilling

A Bessel beam is a non-diffracting beam of concentric rings, each having the same power as the central ring. Technically, a Bessel beam cannot be created as it requires infinite energy. By using an axicon with a collimated Gaussian beam, a beam closely resembling a Bessel distribution is possible. To accomplish this, the projected beam must be close to the conical surface of an axicon. The absolute value of a 0^th order Bessel function of the first kind is shown in Figure 1 (below).

Absolute Value of 0th Order First Kind Bessel
Figure 1: The absolute value of a 0^th order Bessel function. A true Bessel Beam requires each ring to have the same energy as the central peak, thus an infinite amount of energy is needed.

When the beam is projected further from the lens, a ring-shaped beam is formed as seen in Figure 4. The beam is actually conical (i.e., diameter increases with distance), but the rays are non-diverging so that the thickness of the ring remains constant (see Figure 3). The ring's thickness will be half of the input laser beam's diameter. This beam is commonly used in laser-drilling applications.

The photograph below shows a HeNe laser, a former generation Thorlabs' 10X A-coated beam expander, AX255-A axicon, and a DG100X100-600 ground glass diffuser. Although the laser beam's diameter is roughly Ø1 mm, a beam expander increases the beam diameter to Ø10 mm before the axicon. The beam shape is then projected onto a ground glass diffuser. This setup forms a ring, which is shown in Figure 4. When a plano-convex lens is placed after the axicon, the resulting beam will be more focused, and thus a more intense ring will be formed, which can be seen in Figure 5.

Figure 2: A setup including a HeNe laser, beam expander, axicon, and diffuser.

Selection Guide for Prisms

Thorlabs offers a wide variety of prisms, which can be used to reflect, invert, rotate, disperse, steer, and collimate light. For prisms and substrates not listed below, please contact Tech Support.

Beam Steering Prisms

Prism	Material	Deviation	Invert	Reverse or Rotate	Applications
Right Angle Prisms	N-BK7, UV Fused Silica, Calcium Fluoride, or Zinc Selenide	90°	90°	No	90° reflector used in optical systems such as telescopes and periscopes.
Right Angle Prisms	N-BK7, UV Fused Silica, Calcium Fluoride, or Zinc Selenide	180°	180°	No	180° reflector, independent of entrance beam angle. Acts as a non-reversing mirror and can be used in binocular configurations.
Unmounted Retroreflectors and Mounted Retroreflectors	N-BK7	180°	180°	No	180° reflector, independent of entrance beam angle. Beam alignment and beam delivery. Substitute for mirror in applications where orientation is difficult to control.
Unmounted Penta Prisms and Mounted Penta Prisms	N-BK7	90°	No	No	90° reflector, without inversion or reversal of the beam profile. Can be used for alignment and optical tooling.
Roof Prisms	N-BK7	90°	90°	180^o Rotation	90° reflector, inverted and rotated (deflected left to right and top to bottom). Can be used for alignment and optical tooling.
Unmounted Dove Prisms and Mounted Dove Prisms	N-BK7	No	180°	2x Prism Rotation	Dove prisms may invert, reverse, or rotate an image based on which face the light is incident on. Prism in a beam rotator orientation.
Unmounted Dove Prisms and Mounted Dove Prisms	N-BK7	180°	180°	No	Prism acts as a non-reversing mirror. Same properties as a retroreflector or right angle (180° orientation) prism in an optical setup.
Wedge Prisms	N-BK7	Models Available from 2° to 10°	No	No	Beam steering applications. By rotating one wedged prism, light can be steered to trace the circle defined by 2 times the specified deviation angle.
Wedge Prisms	N-BK7	Models Available from 2° to 10°	No	No	Variable beam steering applications. When both wedges are rotated, the beam can be moved anywhere within the circle defined by 4 times the specified deviation angle.
Coupling Prisms	Rutile (TiO₂) or GGG	Variable^a	No	No	High index of refraction substrate used to couple light into films. Rutile used for n_film > 1.8 GGG used for n_film < 1.8

Depends on Angle of Incidence and Index of Refraction

Dispersive Prisms

Prism

Material

Deviation

Invert

Reverse or Rotate

Illustration

Applications

Equilateral Prisms

F2, N-SF11, Calcium Fluoride,
or Zinc Selenide

Variable^a

Dispersion prisms are a substitute for diffraction gratings.

Use to separate white light into visible spectrum.

Dispersion Compensating Prism Pairs

Fused Silica, Calcium Fluoride, SF10, or N-SF14

Variable Vertical Offset

Compensate for pulse broadening effects in ultrafast laser systems.

Can be used as an optical filter, for wavelength tuning, or dispersion compensation.

Pellin Broca Prisms

N-BK7,
UV Fused Silica,
or Calcium Fluoride

90°

Ideal for wavelength separation of a beam of light, output at 90°.

Used to separate harmonics of a laser or compensate for group velocity dispersion.

Depends on Angle of Incidence and Index of Refraction

Beam Manipulating Prisms

Prism

Material

Deviation

Invert

Reverse or Rotate

Illustration

Applications

Anamorphic Prism Pairs

N-KZFS8 or
N-SF11

Variable Vertical Offset

Variable magnification along one axis.

Collimating elliptical beams (e.g., laser diodes)

Converts an elliptical beam into a circular beam by magnifying or contracting the input beam in one axis.

Axicons

UV Fused Silica

Variable^a

Creates a conical, non-diverging beam with a Bessel intensity profile from a collimated source.

Depends on Prism Physical Angle

Polarization Altering Prisms

Prism	Material	Deviation	Invert	Reverse or Rotate	Applications
Glan-Taylor, Glan-Laser, and α-BBO Glan-Laser Polarizers	Glan-Taylor: Calcite Glan-Laser: α-BBO or Calcite	p-pol. - 0° s-pol. - 112°^a	No	No	Double prism configuration and birefringent calcite produce extremely pure linearly polarized light. Total Internal Reflection of s-pol. at the gap between the prism while p-pol. is transmitted.
Rutile Polarizers	Rutile (TiO₂)	s-pol. - 0° p-pol. absorbed by housing	No	No	Double prism configuration and birefringent rutile (TiO₂) produce extremely pure linearly polarized light. Total Internal Reflection of p-pol. at the gap between the prisms while s-pol. is transmitted.
Double Glan-Taylor Polarizers	Calcite	p-pol. - 0° s-pol. absorbed by housing	No	No	Triple prism configuration and birefringent calcite produce maximum polarized field over a large half angle. Total Internal Reflection of s-pol. at the gap between the prism while p-pol. is transmitted.
Glan Thompson Polarizers	Calcite	p-pol. - 0° s-pol. absorbed by housing	No	No	Double prism configuration and birefringent calcite produce a polarizer with the widest field of view while maintaining a high extinction ratio. Total Internal Reflection of s-pol. at the gap between the prism while p-pol. is transmitted.
Wollaston Prisms and Wollaston Polarizers	Quartz, Magnesium Fluoride, α-BBO, Calcite, Yttrium Orthovanadate	Symmetric p-pol. and s-pol. deviation angle	No	No	Double prism configuration and birefringent calcite produce the widest deviation angle of beam displacing polarizers. s-pol. and p-pol. deviate symmetrically from the prism. Wollaston prisms are used in spectrometers and polarization analyzers.
Rochon Prisms	Magnesium Fluoride or Yttrium Orthovanadate	Ordinary Ray: 0° Extraordinary Ray: deviation angle	No	No	Double prism configuration and birefringent MgF₂ or YVO₄ produce a small deviation angle with a high extinction ratio. Extraordinary ray deviates from the input beam's optical axis, while ordinary ray does not deviate.
Beam Displacing Prisms	Calcite	2.7 or 4.0 mm Beam Displacement	No	No	Single prism configuration and birefringent calcite separate an input beam into two orthogonally polarized output beams. s-pol. and p-pol. are displaced by 2.7 or 4.0 mm. Beam displacing prisms can be used as polarizing beamsplitters where 90^o separation is not possible.
Fresnel Rhomb Retarders	N-BK7	Linear to circular polarization Vertical Offset	No	No	λ/4 Fresnel Rhomb Retarder turns a linear input into circularly polarized output. Uniform λ/4 retardance over a wider wavelength range compared to birefringent wave plates.
Fresnel Rhomb Retarders	N-BK7	Rotates linearly polarized light 90°	No	No	λ/2 Fresnel Rhomb Retarder rotates linearly polarized light 90°. Uniform λ/2 retardance over a wider wavelength range compared to birefringent wave plates.

S-polarized light is not pure and contains some P-polarized reflections.

Beamsplitter Prisms

Prism

Material

Deviation

Invert

Reverse or Rotate

Illustration

Applications

Beamsplitter Cubes

N-BK7

50:50 splitting ratio, 0° and 90°

s- and p- pol. within 10% of each other

Double prism configuration and dielectric coating provide 50:50 beamsplitting nearly independent of polarization.

Non-polarizing beamsplitter over the specified wavelength range.

Polarizing Beamsplitter Cubes

N-BK7, UV Fused Silica, or N-SF1

p-pol. - 0°

s-pol. - 90°

Double prism configuration and dielectric coating transmit p-pol. light and reflect s-pol. light.

For highest polarization use the transmitted beam.

Posted Comments:

18840853650 (posted 2017-09-08 10:09:15.43)

你好，我购买了一款AX255-C的锥透镜，想仿真一下1310nm和527nm激光通过该锥透镜后的光斑发布效果，即贝塞尔光发布情况，但是你们给的ZEMAX文件版本太高我用不了，所以想咨询一下你们可以帮我仿真一下这个效果嘛？非常感谢，期待您的回信。

tfrisch (posted 2017-09-15 01:16:54.0)

Hello, thank you for contacting Thorlabs. I will have a representative from our office in China reach out to you about an appropriate format for this optical model.

daniel.comparat (posted 2016-04-12 13:57:18.56)

We found that the center is not precisely machined. For small diameter initial beams (1 mm) the axcicon is more like a lens. I send you an e-mail to the tehnical department to have more news, but I did not received any answer. Could you try to contact them. Best Daniel Comparat

besembeson (posted 2016-04-13 09:57:52.0)

Response from Bweh at Thorlabs USA: We contacted you yesterday to get more details about your application and observations, which may be related to the precision level of the apex rounding of our axicons.

andreas.boenke (posted 2016-01-19 14:21:19.817)

Dear Sirs, can you please provide information about the max. radius of the axicon tip area with significant deviation from the theoretical shape (causing aberrated beam portion) ? This would be interesting for AX2510-A AX255-A AX252-A Thank you for your help. Best regards, Andreas Boenke

besembeson (posted 2016-01-21 11:17:59.0)

Response from Bweh at Thorlabs USA: I will be contacting you with this information.

user (posted 2015-11-19 13:23:45.527)

A tutorial, or some other explanation (ABCD matrix for example) on axicons in the prism guide would be helpful.

myanakas (posted 2015-11-19 09:05:51.0)

Response from Mike at Thorlabs: Thank you for your feedback. We will look into adding this information to our Prism Guide in the future.

dennis-weller (posted 2013-07-02 11:50:34.36)

Can you please send me Zemax-Files of you axicon lenses? Thanks in anticipation!

cdaly (posted 2013-07-09 09:29:00.0)

Thank you for your feedback. We've just updated the webpage to include these files now.

tcohen (posted 2013-01-03 15:07:00.0)

Response from Tim at Thorlabs: The rings could be a result from imperfections in the tip of the axicon, however, the quality of the tip of these optics are unrivaled in the industry and would make this an unlikely reason. Misalignment could contribute. Possibly you are seeing artifacts of the Bessel beam that is generated when a Gaussian beam is inputted. This is touched upon under the “Beam Shape tab on this page. We will work to improve the discussion on this page to better explain the performance of these parts and options you may have to achieve desirable results. We will contact you to troubleshoot this artifact in your setup.

totlab (posted 2012-12-11 23:05:54.373)

We bought a axicon and found the ring is not so clean, and several smaller rings are in the inner side. The laser beam is collimated and dia=2mm. Is it because the imperfection of the tip of the axicon? I found no dust or damage on the surface.

jjurado (posted 2011-02-04 10:57:00.0)

Response from Javier at Thorlabs to info: Thank you very much for contacting us with your inquiry. Since axicons produce a ring-shaped beam, they work well for replacing the dark field patch stop in a dark field microscope. Although we have not yet developed an application in dark field microscopy using axicons, there have been several publications in this field. You can find one of these publications through the following link: http://spiedigitallibrary.org/jbo/resource/1/jbopfo/v13/i4/p044024_s1?isAuthorized=no

info (posted 2011-02-03 14:54:44.0)

Would this be a good lens to use in a the light source path of a dark field microscope?

Axicons (Uncoated)

Zoom

Item #	Physical Angle (α)	Deflection Angle (ß)^a	Center Thickness (t_c)	Wavelength Range	Transmission Curve^b
AX2505	0.5°	0.230°	5.1 mm	185 nm - 2.1 µm	Raw Data
AX251	1.0°	0.461°	5.2 mm
AX252	2.0°	0.922°	5.4 mm
AX255	5.0°	2.314°	6.1 mm
AX2510	10.0°	4.694°	7.2 mm
AX2520	20.0°	9.973°	9.6 mm

Deflection angles calculated for 532 nm light
Transmission curve representative of a 10 mm thick window

These axicons are uncoated and operate in the 185 nm - 2.1 µm wavelength range. The substrate used for these lenses, UV fused silica, is an ideal choice for applications from the UV to the near IR. UV fused silica has better homogeneity and a lower coefficient of thermal expansion than N-BK7.

Axicons (AR Coated: 245 - 400 nm)

Zoom

Item #	Physical Angle (α)	Deflection Angle (β)^a	Center Thickness (t_c)	AR Coating^b	AR Coating Plot^b	Reference Drawing
AX251-UV	1.0°	0.481°	5.2 mm	245 - 400 nm R_avg<0.5%	Raw Data

Deflection angles calculated for 330 nm light.
Per Surface

This axicon is AR coated for the 245 - 400 nm range. It is designed to offer high transmission in the UV range, making it ideal for many ultraviolet applications. Furthermore, the substrate being used (UV fused Silica) offers excellent UV transmission.

Axicons (AR Coated: 350 - 700 nm)

Zoom

Item #	Physical Angle (α)	Deflection Angle (β)^a	Center Thickness (t_c)	AR Coating^b	AR Coating Plot^b
AX2505-A	0.5°	0.230°	5.1 mm	350 - 700 nm R_avg<0.5%	Raw Data
AX251-A	1.0°	0.461°	5.2 mm
AX252-A	2.0°	0.922°	5.4 mm
AX255-A	5.0°	2.314°	6.1 mm
AX2510-A	10.0°	4.694°	7.2 mm
AX2520-A	20.0°	9.973°	9.6 mm

Deflection angles calculated for 532 nm light.
Per Surface

These axicons are AR coated for the 350 - 700 nm range. They are well-suited for applications within part of the near UV (NUV) spectrum and all of the visible spectrum. This range makes these axicons ideal for use with HeNe and other visible lasers.

Axicons (AR Coated: 650 - 1050 nm)

Zoom

Item #	Physical Angle (α)	Deflection Angle (β)^a	Center Thickness (t_c)	AR Coating^b	AR Coating Plot^b
AX2505-B	0.5°	0.226°	5.1 mm	650 - 1050 nm R_avg<0.5%	Raw Data
AX251-B	1.0°	0.453°	5.2 mm
AX252-B	2.0°	0.906°	5.4 mm
AX255-B	5.0°	2.273°	6.1 mm
AX2510-B	10.0°	4.609°	7.2 mm
AX2520-B	20.0°	9.787°	9.6 mm

Deflection angles calculated for 850 nm light.
Per Surface

These axicons are AR coated for the 650-1050 nm range making them suitable for many near IR (NIR) applications, such as optical traps and corneal surgeries.

Axicons (AR Coated: 1050 - 1700 nm)

Zoom

Item #	Physical Angle (α)	Deflection Angle (β)^a	Center Thickness (t_c)	AR Coating^b	AR Coating Plot^b
AX2505-C	0.5°	0.223°	5.1 mm	1050 - 1700 nm R_avg<0.5%	Raw Data
AX251-C	1.0°	0.447°	5.2 mm
AX252-C	2.0°	0.894°	5.4 mm
AX255-C	5.0°	2.244°	6.1 mm
AX2510-C	10.0°	4.551°	7.2 mm
AX2520-C	20.0°	9.659°	9.6 mm

Deflection angles calculated for 1310 nm light.
Per Surface

These axicons are AR coated for the 1050 - 1700 nm range, which makes them great for applications into the near IR (NIR). This covers common wavelengths used in applications such as: optical coherence tomography (OCT), optical trapping, and laser drilling. In these applications, an axicon can increase the depth of focus in the sample arm.

View All »Matching Part Numbers

Axicons

Features

Applications

Axicon Beams

Selection Guide for Prisms

Beam Steering Prisms

Dispersive Prisms

Beam Manipulating Prisms

Polarization Altering Prisms

Beamsplitter Prisms

Axicons (Uncoated)

Axicons (AR Coated: 245 - 400 nm)

Axicons (AR Coated: 350 - 700 nm)

Axicons (AR Coated: 650 - 1050 nm)

Axicons (AR Coated: 1050 - 1700 nm)