What is a beam expander used for?
Laser beam expanders increase the diameter of a collimated input beam to a larger collimated output beam for applications such as laser scanning, interferometry, and remote sensing.
How do you reduce the size of a beam?
The only way to make the spot size smaller is to use a lens of shorter focal length or expand the beam. If this is not possible because of a limitation in the geometry of the optical system, then this spot size is the smallest that could be achieved.
Can you deflect laser beam?
The only method to deflect a laser beam is via a mirror.
What is a cO2 laser beam expander?
A device that take a collimated beam of light and expand its size. Composed with two lens of different curvature to obtain good effect. Different times of expander for different requirments. Widely used for cO2 laser Marking machines.
How do you calculate divergence of a beam?
One may also simply measure the beam intensity profile at a location far away from the beam waist, where the beam radius is much larger than its value at the beam waist. The beam divergence angle may then be approximated by the measured beam radius divided by the distance from the beam waist.
What is beam focusing?
Beam focusing refers to creating a narrow point in the cross-section of the ultrasound beam called the focal point. It is at the focal point where the lateral resolution of the beam is the greatest also. Before the focal point is the near field or Fresnel zone, where beams converge.
What is tube lens?
A tube lens is placed within the body tube between the objective and the eyepieces to produce the intermediate image.
How are the lenses separated in a beam expander?
The lenses are separated by the sum of their focal points, except that the diverging lens has a negative focal length. A beam input into the diverging lens propagates to the converging lens without reaching an intermediate focal point. A Keplerian beam expander has two converging lenses,…
What is the easiest beam expander to build?
The easiest beam expander to build is a Keplerian Telescope. In the Keplerian model the focal lengths of both lenses will be positive, their addition resulting in a focal point in the gap between the lenses at the point where the two focal lengths meet.
How does a Galilean beam expander work?
A Galilean beam expander consists of one diverging lens and one converging lens. The lenses are separated by the sum of their focal points, except that the diverging lens has a negative focal length. A beam input into the diverging lens propagates to the converging lens without reaching an intermediate focal point.
What is the difference between laser beam expander and Keplerian telescope?
When the magnifying power is less than 1, the telescope minifies. In a laser beam expander, the placement of the objective and image lenses is reversed. Keplerian beam expanders consist of two lenses with positive focal lengths separated by the sum of their focal lengths.