What is LASER? – Construction, Types, and Applications

LASER stands for Light Amplification by Stimulated Emission of Radiation. A LASER is a source of light which produces a very narrow beam of light that is useful in many technologies and instruments.

Construction and Working of LASER

The construction of a typical red LASER is shown in the figure.

It contains a long crystal of made ruby with a flash tube (which is not shown for simplicity, instead directly pump light is shown) wrapped around it.

Here, a high voltage electric power supply makes the tube flash on and off. When the tube flashes, it pumps energy into the ruby crystal. The flashes it makes inject energy into the crystal in the form of photons. The atoms of the ruby crystal absorb this energy and thus the electrons of the atoms jump to a higher energy level.

Now, after few milliseconds, the electrons return to their ground level by giving off a photon of light, this is known as spontaneous emission. The photons that atoms give off zoom up and down inside the ruby crystal and travelling at a speed of light. One of these photons stimulate an already existing atom. When this happens, the excited atom gives off a photon and we get the original photon as well. This is known as stimulated emission.

Now, one photon of light has produced two photons so the light has been amplified. The escaping photons from the crystal form a very concentrated beam of powerful LASER light.

Types of LASER

Depending upon the LASER medium used, the LASER be classified into following types −

• Gas LASER

• Liquid LASER

• Chemical LASER

• Semi-conductor LASER

• X-Ray LASER

Advantages of LASER

The advantages of the LASER include the following −

• LASER light travels to very long distances without any distortion

• LASER has high information carrying capability. Therefore, it can be used in data communication

• It is free from electromagnetic interference.

• LASER provides minimum signal leakage.

• LASER light is less harmful than X-rays.

Disadvantages of LASER

The disadvantages of the LASER light are listed below −

• LASER devices are very costly.

• While using LASER, safety precautions needed.

• LASER can damage the human organs.

• LASER requires other equipment like operating equipment and control gears, etc.

Applications of LASER

The LASER is used for the following −

• For special lighting effects in media work.

• In computers, CD/DVD drives, etc.

• LASER light can be used for beautification.

• It can be used in medical equipment.

• LASER light is also used in metal processing industries.

• LASER is also used in defence applications.