LASER BEEM HOW TO

The optical power of a laser beam may hardly change during propagation in a transparent medium, or quickly decay in an absorbing or scattering medium. Laser light often have a small optical bandwidth, so that the temporal coherence is also high.Īn often unwanted consequence of the high level of coherence is the tendency to form laser speckle patterns. In this case, the equations cannot predict the detailed evolution of beam profile, but only of the beam radius based on the second moment of the intensity profile (D4σ method). In cases with non-ideal beam quality, one can use a generalized set of equations which also involves the so-called beam quality factor M 2. The propagation of Gaussian beams can be calculated with a set of relatively simple equations. When a laser beam hits some object (for example a workpiece in laser material processing), the arriving optical intensity is also called the irradiance. Generally, laser beams exhibit a high degree of spatial coherence, which is related to a high beam quality.Īs a result, one obtains good focusability and the potential to form collimated beams with very low beam divergence. In this example, the beam radius is only slightly larger than the wavelength, and the beam divergence is strong. Snapshot of the electric field distribution around the focus of a Gaussian beam. Laser beams are often close to Gaussian beams, where the transverse profile of the optical intensity can be described with a Gaussian function, the width of which varies along the propagation direction. This means that the light dominantly propagates in a certain direction, typically with most of the optical power concentrated to a small area of the order of a square millimeter. In most cases, a laser emits light in the form of a well directed laser beam.

LASER BEEM HOW TO

How to cite the article suggest additional literature More specific terms: collimated beams, Gaussian beams, diffraction-limited beams, flat-top beamsĬategories: general optics, laser devices and laser physics Encyclopedia > letter L > laser beams Laser Beamsĭefinition: light beams propagating dominantly in one direction

Laser beem