Table of Contents
What do you mean by divergence of laser beam?
The beam divergence defines how much the beam spreads out over increasing distance from the optical aperture. Beam divergence is defined by the full angle. In laser diodes, beam divergence is specified with two values because of the presence of astigmatism (see Diodes vs. HeNe).
How do you reduce the diameter of a laser 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.
What determines the intensity of a laser?
In optical physics, the intensity I, e.g. of a laser beam at some location, is generally understood to the optical power per unit area, which is transmitted through an imagined surface perpendicular to the propagation direction. The intensity is the product of photon energy and photon flux.
Which of the following apparatus are used to determine the divergence of laser beam?
Generally, the beam divergence of laser beam is measured using beam profiler. Lasers usually emit beams with a Gaussian profile. A Gaussian beam is a beam of electromagnetic radiation whose transverse electric field and intensity (irradiance) distributions are described by Gaussian functions.
What are the characteristics of lasers that make it different from other light sources?
Laser radiation has the following important characteristics over ordinary light source. They are: i) monochromaticity, ii) directionality, iii) coherence and iv) brightness. (i) Monochromaticity: A laser beam is more or less in single wavelength. i.e., the line width of laser beams are extremely narrow.
How do you collimate a diverging laser beam?
To collimate a diverging light source with a lens, you can place the lens a distance away from the source, equal to the focal length of the lens. Here, we have a diverging beam of light and a positive lens at a distance equal to the focal length away.