Laser is an acronym for light amplification by simulator emissions of production radiation in 1960 lesser was introduced as an appealing method for the production of highly directional, coherent, and and monochromatic and polarile polarized light beam the principles of lesser is tasted on the phenomenon of simulated emission of radiation by any stain in 1917.

What are the characteristics of laser light

• Coherence: the light form of a laser is said to be coherent which means that the wavelength of the laser light are in phase in space and time.
• Highly monochromatic: the light form a laser type Kelly games from one atomic transmissions with a single wavelength. So the laser light has a single spectral colour and is highly monochromatic light available
• Highly directional and coordinator: laser EMIT light that highly directional, narrow beam devergence. The light from laser emergence is an extremely thin beam with very little Devraj difference therefore the beam is also highly collimated
• Brightness : the radiation of laser is an important parameter. It is defined as the power emitted per unit surface area per unit solid angle. Laser beams are very bright

Components for laser 

Active medium 

It is the material in which the laser action takes place. The active medium maybe solid crystals such as Ruby or in the y a g, liquid diceps like CO2 or helium neon or semiconductor such as gas. This medium decided the wavelength of laser radiation. Medium contain atoms which can produce set more suitable emissions that spontaneous emissions and cases of applications. They are called active centre 

Energy source 

Energy source pumps the active centres from ground state to exit state to achieve population investment. The pumping by energy source can be optical electrical or chemical depending on the active medium 

Resonance cavity 

Resonance cavity consists of active medium enclosed between 2 mirrors. One is highly reflected mirror and the other is parallely transmits mirror full stop for it is its operation population in inversion is much needed. When a group of atoms or molecules exist with more electrons is an existed than in lower energy States population inversion takes place

    Principles ofLaserActions 

• Absorption
• spontaneous emission
• simulated emission

  population inversion 

In absorption and income Photon activites the atomic system from a lower energy state into higher energy state.

Atom just exactly the proper energy to induce an electronic transition between two energy States 

Spontaneous emission

It take place when an electron in a higher energy level drop down to a lower energy level and a photon is emitted with an energy equal to the energy difference between the two levels