LASER Technology | Properties Of A LASER Beam

LASER Beam Properties:

Laser is a powerful source of light having extraordinary properties which aren’t found within the traditional light sources like incandescent lamps, mercury vapour lamps, etc. the unique property of laser is that its light waves travel to a terrible distances with little or no divergence. Just in case of a standard source of light, the light is emitted in a jumble of separate waves that cancel each other at randomly, therefore the light can travel very short distances only.

A high degree of monochromatic and directional properties which makes superior than the standard light beams. Therefore in a laser beam the light waves not only are in the same phase, however constant color throughout the journey.

The main characteristics that affecting the beam properties of laser include:

1. Size of the gain medium

2. Location

3. Separation

4. Reflectivity of the mirrors of the optical cavity

5. Presence of losses within the beam path inside the cavity

Some of these features determine the unique properties of the laser beam, mentioned as laser modes. The laser modes are having wavy properties (with reference to the oscillating character of the beam). The beam passes back and forth through the amplifier and grows very large at the expense of existing losses.

Most lasers have several modes of waves operate at the same time in the form of both longitudinal and transverse / cross modes which give rise to a complex frequency and spatial structure within the beam which otherwise seems as a simple pencil like beam of light.

Types of LASER’s:

The first laser action was demonstrated in a ruby crystal by Theodore Maiman in 1960. Since then, a large number of materials in various media have been found to give laser action at wavelengths in the visible, ultraviolet and infrared regions. In addition to the ruby crystal, many other crystals doped (introduced as an impurity) with rare earth ions (like Neodymium) have light been found to give extremely good laser output. The crystals are grown in specially designed furnaces with the desired compositions and then cut and polished into cylindrical laser rods with the faces optically flat and parallel to each other.

The broad categories are:

1. Optically pumped solid state lasers

a. Ruby Laser

b. Rare Earth ion Lasers (Neodymium (Nd)

c. Nd:YAG lasers (Neodymium : Yttrium Aluminum Garnet)

d. Nd:Glass Lasers

e. Tuneable Solid state Lasers

2. Liquid (Dye) lasers

3. Gas lasers

a. Helium Neon Lasers

b. Argon Krypton ion Lasers

c. Carbon dioxide Lasers

d. Excimer Lasers

4. Semiconductor lasers

5. Free electron lasers

6. X- ray lasers

7. Chemical lasers

Laser Applications:

Drilling – 1.8%

Welding – 18.7%

Marking (Inscribe) – 20.5%

Microelectronics – 5.4%

Cutting – 44.3%

Others – 9.3%