Plano-Convex (PCX) Ring Grade Axicons are used in generating ring profile laser beams and are available in several different Apex Angles from 90° to 160°. They feature controlled apex angle tolerances that create precise ring profiles. Plano-Convex (PCX) Ring Grade Axicons utilize a precision fused silica substrate and can be purchased with a broadband anti-reflection coating or as uncoated substrates. For axicons used to create diffraction-free Bessel Beams, Plano-Convex (PCX) Bessel Grade Axicons are available.
Note: For more information on axicons, please review our application note: An In-Depth Look at Axicons.
The ring thickness (t) is easily defined by taking ½ of the beam diameter (db):
The diameter of the ring (dr) is defined using the length from lens output to image (L), the index of refraction of the lens material (n), and the angle (a) and can be approximated as follows:
For optimum performance, we recommend using Plano-Convex (PCX) Axicons in conjunction with one of our beam expanders in order to ensure a beam diameter of at least 50% of the clear aperture.