Conical lenses are often used to generate beams of Bessel intensity distribution or conical non-divergent beams. When the collimating beam is changed into a ring beam, the plane of the conical lens should face the collimating source.
A conical lens refracts light in accordance with Snell's law. Can be used to measure deflection Angle:
Where, n is the refractive index of the glass, α is the physical base Angle of the cone lens, ß is the deflection Angle generated by refracted light and optical axis.
Because of the conical shape of the conical lens, the annular beam profile can be generated with the help of an axial prism. The diameter of the annular beam depends on the Angle and increases as the distance between the axial prism and the focal plane increases. Cone lenses are mainly used for beam shaping and various laser applications. They can also be used to generate non-diffracted Bessel-like beams. A region with a nearly constant distribution of strength, whose length is defined by the Angle and diameter of the axial cone, is interesting here. Bessel beams are ideal for medical, research and metrological applications. By combining multiple axial prisms or lenses, various beam profiles can be generated, such as collimating annular beams or variable annular focal points.