Collimated beams
2024-1-7
Definition:
A laser beam with a small divergence angle.
A collimated beam is a beam (usually a laser beam) that has a small beam divergence angle so that the beam radius does not change significantly after a certain propagation distance. The simplest and most common case is a Gaussian beam, which means that the Rayleigh length is longer than the assumed propagation distance.
A Shack-Hartmann sensor or a specific interferometer can be used to measure the change in the beam radius over a certain distance in the free space of the beam, thereby checking whether the beam is collimated.
In fiber optics, fiber collimators are usually used. Suitable for bare optical fibers and optical fibers that need to be connected, that is, optical fibers that need to be connected with fiber optic connectors.
Figure 1: Lenses can collimate light emerging from an optical fiber, or direct a collimated beam of light into an optical fiber.
Collimated beams are very useful in general experiments, because the beam radius basically remains unchanged during the propagation process, so the distance between each optical device can be easily changed in the experiment without any additional optical devices, and It will not make the beam radius larger.
The output beam of most solid-state lasers is inherently collimated. A planar output coupler can obtain an output with a planar wavefront, and the beam waist radius will be large enough to avoid excessive divergence angles.
A laser beam with a small divergence angle.
A collimated beam is a beam (usually a laser beam) that has a small beam divergence angle so that the beam radius does not change significantly after a certain propagation distance. The simplest and most common case is a Gaussian beam, which means that the Rayleigh length is longer than the assumed propagation distance.
A Shack-Hartmann sensor or a specific interferometer can be used to measure the change in the beam radius over a certain distance in the free space of the beam, thereby checking whether the beam is collimated.
In fiber optics, fiber collimators are usually used. Suitable for bare optical fibers and optical fibers that need to be connected, that is, optical fibers that need to be connected with fiber optic connectors.
Figure 1: Lenses can collimate light emerging from an optical fiber, or direct a collimated beam of light into an optical fiber.
Collimated beams are very useful in general experiments, because the beam radius basically remains unchanged during the propagation process, so the distance between each optical device can be easily changed in the experiment without any additional optical devices, and It will not make the beam radius larger.
The output beam of most solid-state lasers is inherently collimated. A planar output coupler can obtain an output with a planar wavefront, and the beam waist radius will be large enough to avoid excessive divergence angles.
