how does a laser works

in the following way. The system can be a solid, liquid or gas but is taken in the form of a cylinder. A system is chosen which has a lower energy E 1 , a higher energy E 2 . Using some technique the number of atoms in state E 2 is made higher than that in state E 1 . In this situation a photon ..

How a Laser Works - The below figure shows schematically how a population inversion can be achieved so that laser action-or lasing us it is called can occur. Atoms from the ground state E 1 are "pumped" up to an excited state E 3 , for example by th..

It is an acronym for Light Amplification By Stimulated Emission Of Radiation . It is a process by which we get a coherent, highly monochromatic and perfectly parallel beam of light. Lasers may also be called as optical masses. It has been invented and developed in 1959. The laser..

The plane of the coil is horizontal and the split ring S 1 touches the brush B 1 while the split ring S 2 touches the brush B 2 . The brush B 1 is connected to the anode of the d.c. battery while the brush B 2 is connected to the cathode. The current flows in the coil in the direction ABCD. The arm..

Diagnostic Kits - Laser Microsurgery - Microsurgery is any operation done with the aid of microscopes. Surgeons work with spectacle - mounted magnifiers or with microscopes. Using this technique, surgeons can remove adenoma, tumours of the pituitary gland, without damaging the g..

. Spontaneous emission to the ground state level E 0 is very rare. Level E 3 in helium (= 20.61 eV) is, by chance, very close to level E 2 in neon (= 20.66 eV). So, during collisions between helium and neon atoms, the excitation energy of the helium can be readily transferred to the neon. In this w..

The minimum amount of energy required to emit electrons from a metal surface is called the work function or threshold energy of that metal. The number of electrons emitted per second i.e. the rate of emission depends upon the material of the surface temperature of the surface area..

It is material in which the laser action is made to take place. It may be solid, liquid or gas. Many lasers are named after the material used e.g. ruby laser, He-Ne laser, CO 2 laser, Nd: YAG laser etc. The most important characteristic ..

The smallest lasers used for telephone communication over optical fibres have as their active medium a semiconducting gallium arsenide crystal about the size of a pin-hea..

Ruby Laser - In 1960, T .H. Maiman constructed the first laser using a Ruby crystal. Ruby is a crystalline form of silica(Al 2 O 3 ) with a slight natural doping of chromium. It has the following advantages for being used as a laser. (i) It is a solid having suitably a..