Detailed descriptive presentation over fundamentals of LASER technology.

1. LASERS
PREPARED BY:
1.)RAJET VESHIN
2.)ARJUN GUPTA
3.)KASHYAP GUPTA
4.)MOVIN KUMAR
5.)SUDANSHU GUPTA
6.)RAJNEESH SHARMA
7.)BHAANU JAMWAL
DR. PRIYANKA KANWAL

3. • Laser stands for Light Amplification by Stimulated Emission
of Radiation
• Lasers are more powerful radiation than ordinary light.
• Lasers have wide application in holography and fiber optics.

4. • Stimulated Emission was predicted by EINSTEIN in 1917.
• Microwave Amplification by Stimulated Emission of Radiation in 1954
• MASER principle was extended to optical frequencies by SCHAWLAW
and TOWNES in 1958.
• The concept of LASER began in the year 1958..
• First successful operation of a laser demonstrated by MAIMAN in 1960
using RUBY crystal (three level system)
• Then experiments were switched over on to He-Ne laser (Four level
system)

5. • COHERENCE
• HIGH INTENSITY
• HIGH DIRECTIONALITY
• HIGH MONOCHROMATICITY

6. • Stimulated Absorption or Induced Absorption
• Spontaneous Emission.
• Stimulated or Induced Emission.
The phase, the direction and the state of polarisation of induced photon
is same as that of incident photon .Due to this, intensity of radiation
passing through atoms, get amplified.

7. • Meta-stable State: The inter-mediate state between the ground state and the
excited state where the average life time of atom to persist is more than 1/10³
sec is called meta-stable state.
• Population inversion : The situation in which the number of atoms in the
higher energy state is greater than that in the lower energy state is known as
population inversion.
• Pumping : The procedure adopted to achieve population inversion is called
pumping.

8. • The active medium which provides amplification.
• The pumping source provides the energy to the active medium to
attain population inversion.
• The optical resonator enables us to get LASER on one hand and on
other hand , some part of output energy is fed back to the system to
have a resonance in the process.

9.  THE RUBY LASER
 THE HELIUM-NEON LASER
 SEMICONDUCTOR LASER
 CHEMICAL LASER
Max. Intensities: 100GW/cm2 at 15μm spot

10.  1. In industry
For welding and melting
For cutting and drilling holes
To test the quality of materials
 2. In medicine
Used for the treatment of detached retinas.
Used in performing micro and bloodless surgery.
Used for the treatment of human and animal cancers and skins
tumours.
 3. Military application
The laser beam can serve as a wave weapon called as Death Ray.
 4. Science and engineering applications
It is used in fiber optic communication.
It is used in holography.
It is used in accelerating chemical reactions.

11. • Holography is a technique which enables three-dimensional images to
be made. It involves the use of a laser, interference, diffraction, light
intensity recording and suitable illumination of the recording. The
image changes as the position and orientation of the viewing system
changes in exactly the same way as if the object were still present, thus
making the image appear three-dimensional.
• The holographic recording itself is not an image; it consists of an
apparently random structure of either varying intensity, density or
profile.

12. THANK YOU…………