Beam expander

What is a Beam Expander?

A beam expander is an optical device that is used to increase the diameter of a laser beam. It is designed to expand the beam while preserving its collimation, which means that the beam remains parallel after expansion. The beam expander consists of two lenses with different focal lengths, which are separated by a distance equal to the sum of their focal lengths. The first lens expands the beam while the second lens collimates it, resulting in a larger, parallel beam.

Beam expanders are used in a wide range of applications, including microscopy, lithography, and laser cutting. They are especially useful in applications where a large beam diameter is required, such as in laser cutting, where the beam needs to be precise and uniform across a wide area. Beam expanders can also be used in scientific research, where the expanded beam can be used to examine microscopic structures.

Types of Beam Expanders

There are two main types of beam expanders: Galilean and Keplerian. Galilean beam expanders use a positive and negative lens arrangement, where the negative lens is placed closer to the source of the beam, while the positive lens is placed further away. This type of beam expander is typically used for low-power applications, as it has a limited expansion ratio. Keplerian beam expanders, on the other hand, use two positive lenses and are capable of higher expansion ratios. They are commonly used in high-power applications, such as laser cutting and welding.

Applications of Beam Expanders

Beam expanders are essential tools in many applications that use lasers. One of their primary uses is in laser cutting, where a beam expander is used to create a precise, uniform beam that can cut through materials with high accuracy. Beam expanders are also used in microscopy, where they allow researchers to examine microscopic structures with greater precision by expanding the beam to cover a wider area.

In addition, beam expanders are used in lithography, where they are used to create patterns on a substrate. They are also used in laser marking, where the beam is expanded to create a larger spot size, resulting in a deeper and more precise mark. Finally, beam expanders are used in scientific research, where they are used to examine the properties of materials and structures.

Example of a Beam Expander in Use

One example of a beam expander in use is in laser cutting. Laser cutting is a process in which a laser beam is used to cut through materials such as metal, wood, and plastic. The beam must be precise and uniform in order to cut through the material with high accuracy. This is where a beam expander comes in. By expanding the beam, a beam expander creates a larger, uniform beam that can be focused on the material to be cut. This allows for more precise cuts that are uniform across a wider area, resulting in a higher quality finished product.