Convex Spherical-Axicon Lens , Laser Beam Shaping

Product Description:

A convex spherical-axicon lens, also known as a conical lens or axicon lens, is a specialized optical lens that combines the properties of both a convex spherical lens and an axicon lens. It is a conical-shaped lens with a curved, convex surface on one side and a conical surface on the other side.

The convex spherical surface of the lens is typically used to focus or collimate light like a traditional lens. It has a positive focal length, which means it brings parallel rays of light to a focal point after passing through the lens. This property allows the lens to focus or concentrate light onto a specific point or area.

The conical surface of the lens is responsible for its unique properties. Unlike a traditional lens, which focuses light into a single point, the axicon lens focuses light into a ring-shaped pattern. The angle of the cone determines the size and shape of the resulting ring pattern. The ring pattern can be thought of as a series of concentric circles, with the center of the lens being the common focal point of all the circles.

Key Parameters:

Several lens design parameters can affect the ring pattern generated by a convex spherical-axicon lens. Here are some common parameters to consider:

1. Cone Angle (α):  The cone angle directly influences the size and shape of the resulting ring pattern. A smaller cone angle produces a larger diameter and narrower width, while a larger cone angle produces a smaller diameter and wider width.
2. Focal Length: The focal length of the convex spherical surface of the lens affects the convergence or divergence of the light passing through the lens. It can influence the size and focus of the ring pattern. Shorter focal lengths tend to produce wider ring patterns, while longer focal lengths produce narrower ring patterns.
3. Lens Diameter: The diameter of the lens can impact the overall size of the ring pattern. A larger lens diameter typically results in a larger ring diameter, while a smaller lens diameter produces a smaller ring diameter.
4. Surface Curvature: The curvature of the convex spherical surface can affect the shape and symmetry of the ring pattern. Changes in the curvature can introduce aberrations or distortions in the ring pattern.
5. Material Refractive Index: The refractive index of the lens material affects the propagation of light through the lens, which can influence the ring pattern. Different refractive indices can lead to variations in the diameter and width of the ring pattern.
6. Incident Light Wavelength: The wavelength of the incident light can affect the diffraction and interference patterns observed in the ring pattern. Different wavelengths can result in variations in the characteristics of the ring pattern.

It's important to note that these parameters interact with each other, and optimizing them requires careful consideration and evaluation based on the specific application requirements.

Applications:

The combination of the convex spherical surface and the axicon surface in a convex spherical-axicon lens allows for a range of applications. One common use is in laser beam shaping. By passing a collimated laser beam through the lens, the resulting ring pattern can be used for various purposes, such as creating doughnut-shaped laser beams for optical trapping or generating Bessel beams with extended depth of focus.

Convex spherical-axicon lenses are also used in microscopy, fiber optics, and other optical systems where the ability to shape or manipulate light is required. Their unique properties make them valuable tools for a wide range of applications in science, engineering, and industry.