Lasers

Lasers

Theory of laser - characteristics - Spontaneous and icients - population inversion – Nd-YAG laser CO2 laser - Semiconductor laser - Basic applications of lasers in industry.

Introduction

LASER stands for Light Amplification by Stimulated Emission of Radiation.

Laser is a device which emits a powerful, monochromatic, collimated beam of light. The emitted light waves from laser source are coherent in nature.

Two light waves are said to be coherent, when they have the same phase or constant phase difference.

Laser is an artificial light source which exhibits many superior features than the conventional light source.

Laser light emerges as a narrow beam which can travel long distance without much loss of intensity and energy. Actually, the laser amplifies the light waves.

The first laser, ruby laser was invented by Dr. T.H. Maiman in the year 1960.

Since then, the development of lasers is extremely rapid with laser action being demonstrated in many solids, liquids, gases and semiconductors.

The discovery of laser made an enormous impact on scientific and engineering applications particularly in the fields of communication, metrology, biology, medicine and computers.