|Asphericon SPA Aspheric Lens Features
- UV Fused Silica Substrate for Broadband Transmission
- Ø25.4 mm (Ø1")
- 5 mm (0.2") Edge Thickness
- AR-Coated for Maximum Transmission
- Laser Drilling/Optical Trepanning
- Optical Trapping
- Optical Coherence Tomography (OTC)
- Corneal Surgery
Axicons, also commonly referred to as rotationally symmetric prisms, are lenses that feature one conical surface and one plano surface. It is 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.
This Thorlabs’ precision-polished Ø25.4 mm (Ø1) axicon is 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-powered laser applications. Our axicons have an anti-reflection coating for 1050-1620 nm (C-coating). This coating reduces surface reflections from the lens to maximize transmission (Ravg <0.5%).
- C Coating: 1050-1620 nm
- Center Thickness: 5.1 mm
- Edge Thickness: 5 mm
- Edge Thickness Tolerance: +0.1/-0.0 mm
- Diameter: 1" (25.4 mm)
- Angle: 0.5°
- Angular Tolerance: ±0.01%
- Surface Quality: 40-20
- Surface Deviation (RMS): <0.07 µm
- Clear Aperture: >90% of Diameter
- 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 Guassian 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.