A laser works by stimulating the emission of electromagnetic radiation through optical amplification. It produces light that is monochromatic, coherent, highly intense, and directional. There are different pumping schemes that can be used in lasers, including optical pumping, electrical discharge, inelastic atom-atom collisions, and direct conversion. Common types of lasers are ruby lasers, He-Ne lasers, Nd-YAG lasers, CO2 lasers, excimer lasers, dye lasers, and chemical lasers. Lasers find applications in welding, drilling, cutting, optical disks, security, data storage, and medicine.

2. A laser is a device that emits light through a process of optical
amplification based on the stimulated emission of electromagnetic
radiation. The term "laser" originated as an acronmy for Light
Amplification by Stimulated Emission of Radiation.
LASER PROPERTIES
1. M O N O C H R O M A T I C
2. C O H E R E N T
3. H I G H I N T E N S I T Y
4. D I R E C T I O N A L I T Y

3. 1.OPTICAL PUMPING
2.ELECTRICAL DISCHARE
3.INELASTIC ATOM-ATOM COLLISION
4.DIRECT CONVERSION

4. 1.TWO LEVEL PUMPING SCHEME
2.THREE LEVEL PUMPING SCHEME
3.FOUR LEVEL PUMPING SCHEME

8. 1. R U B Y L A S E R S
2. H E – N E L A S E R S
3. N D – Y A G L A S E R S
4. C 0 2
LASERS
5. E X C I M E R L A S E R
6. D Y E L A S E R S
7. C H E M I C A L L A S E R S
8. F R E E E L E C T R O N L A S E R S

12. 1. U S E D F O R W E L D I N G
2. D R I L L I N G
3. C U T T I N G
4. O P T I C A L D I S K S Y S T E M
5. S E C U R I T Y P U R P O S E S
6. O P T I C A L D A T A S T O R A G E
7. I N M E D I C A T I O N F I E L D S