Axicons
| Common Specifications |
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| Substrate Material | UV Fused Silica | | Diameter | 1" (25.4 mm) | | AR Coating Range | 290 - 370 nm (-UV Coating)
350 - 700 nm (-A Coating)
650 - 1050 nm (-B Coating)
1050 - 1620 nm (-C Coating) | | Reflectance over AR Coating Range | Ravg < 0.5% | | Surface Quality | 40-20 Scratch-Dig | | Clear Aperture | >90% of Diameter | | Edge Thickness | 5.0 mm | | Center Thickness Tolerance | +0.1 mm / -0.0mm |
Features - Ø25.4 mm (Ø1")
- Six Angles Available: 0.5°, 1.0°, 2.0°, 5.0°, 10.0°, and 20.0°
- AR Coated for Maximum Transmission
Applications- Laser Drilling/Optical Trepanning
- Optical Trapping
- Optical Coherence Tomography (OCT)
- Corneal Surgery
- Telescopes
Axicons, also commonly referred to as rotationally symmetric prisms, are lenses that feature 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 should face the collimated source. For more information, please see the Beam Shape tab above. Thorlabs' precision-polished axicons Ø25.4 mm ( Ø1") are offered with base angles from 0.5° to 20°. These axicons are made from high-quality UV Fused Silica using computer numerical controlled (CNC) grinding and polishing machines. This provides a high-quality surface, making them ideally suited for high-power laser applications. Our axicons have an anti-reflection coating for one of four ranges: -UV (290 - 370 nm), -A (350 - 700 nm), -B (650 - 1050 nm), and -C (1050 -
1620 nm). These coatings reduce surface reflections from the lens to maximize transmission (Ravg < 0.5%). For an uncoated axicon or a custom coating, please contact Tech Support for a quote.
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To see what each symbol means, please click the info icon in the Reference Drawing column of the table below. 
| Item #* | Angle (α) | Angular
Tolerance | Center
Thickness | Edge Thickness
Tolerance | Surface
Deviation (RMS) | Reference
Drawing |
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| AX2505 | 0.5° | ±0.01% | 5.1 mm | +0.1/-0.0 mm | <0.07 µm |  | | AX251 | 1.0° | ±0.01% | 5.2 mm | +0.1/-0.0 mm | <0.07 µm | | AX252 | 2.0° | ±0.01% | 5.4 mm | +0.1/-0.0 mm | <0.07 µm | | AX255 | 5.0° | ±0.01% | 6.1 mm | +0.1/-0.0 mm | <0.07 µm | | AX2510 | 10.0° | ±0.01% | 7.2 mm | +0.1/-0.0 mm | <0.07 µm | | AX2520 | 20.0° | ±0.01% | 9.6 mm | +0.1/-0.0 mm | <0.07 µm |
*Specifications are the same for the -UV, -A, -B, and -C AR-Coatings.
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 Fig 3: Axicon ray tracing diagram.  Fig 4: The photograph above shows the beam of a collimated laser beam after it is transmitted by an axicon.  Fig 5: The photograph above shows the beam from Fig 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 0th order Bessel function of the first kind is shown in Fig 1 (below). 
Fig 1: The absolute value of a 0th 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 Fig 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 Fig 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, BE10M-A 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 Fig 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 Fig 5.
Fig 2: A setup including a HeNe laser, beam expander, axicon, and diffuser.
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Selection Guide for PrismsThorlabs offers a wide variety of prisms, which can be used to reflect, invert, rotate, disperse, steer, and collimate light. Prisms are available in N-BK7, UV Fused Silica, F2, N-SF11, α-BBO, N-KZFS8, Ge, and CaF2. For prisms and substrates not listed below, please contact tech support. Beam Steering Prisms| Prism | Material | Deviation | Invert | Reverse or Rotate | Illustration | Applications |
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| Right Angle Prisms | N-BK7, UV Fused Silica, Germanium, or Calcium Fluoride | 90° | 90° | No |  | 90° reflector, independent of entrance beam angle. Used in optical systems such as telescopes and periscopes. | | 180° | 180° | No |  | 180° reflector, independent of entrance beam angle. Acts as a non-reversing mirror and can be used in binocular configurations. | 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. | 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° | 180o Rotation |  | 90° reflector, inverted and rotated (deflected left to right and top to bottom). Can be used for alignment and optical tooling. | 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. | | 180° | 180° | No |  | Prism acts as a non-reversing mirror. Same properties as a retro-reflector 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. | | 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* | No | No |  | High index of refraction substrate used to couple light into films. Rutile used for nfilm > 1.8 GGG used for nfilm < 1.8 |
* Depends on angle of incidence and index of refraction
Dispersive Prisms
| Prism | Material | Deviation | Invert | Reverse or Rotate | Illustration | Applications |
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| Equilateral Prisms | F2, N-SF11, Germanium, or Calcium Flouride | Variable* | No | No |  | Dispersion prisms are a substitute for diffraction gratings. Use to separate white light into visible spectrum. | | Pellin Broca Prisms | N-BK7, UV Fused Silica, or CaF2 | 90° | 90° | No |  | 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. | | Dispersion Compensating Prism Pairs | Fused Silica, CaF2, SF10, or N-SF14 | Variable Vertical Offset | No | No |  | Compensate for pulse broadening effects in ultrafast laser systems. Can be used as an optical filter, for wavelength tuning, or dispersion compensation. |
* Depends on angle of incidence and index of refraction Beam Manipulating Prisms| Prism | Material | Deviation | Invert | Reverse or Rotate | Illustration | Applications |
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| Anamorphic Prism Pairs | N-KZFS8 or N-SF11 | Variable Vertical Offset | No | No |  | 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. |
Polarization Altering Prisms| Prism | Material | Deviation | Invert | Reverse or Rotate | Illustration | Applications |
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| 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°* | 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
Wollaston Polarizers | Calcite | 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. | | 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 90o separation is not possible. | | Fresnel Rhomb Retarders | N-BK7 | Linear to circularly 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. | | 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
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290 - 370 nm AR Coating
Axicons
