Nd:YAG lasers emit light at a wavelength of 1.064 μm. They use neodymium-doped yttrium aluminum garnet (Nd:YAG) as the active medium and are optically pumped by a xenon flash lamp. Nd:YAG lasers can operate in pulsed mode and produce up to 20 kW of power output. They use an optical resonator formed between partially and fully reflective mirrors to produce stimulated emission along the length of the Nd:YAG rod. Lasers have applications in fields like medicine, communications, industry, science and technology, and the military.

1. (Construction and Working, Application of laser in various fields)
Presentation by

2. Type : Doped Insulator Laser
Active Medium : Yttrium Aluminium Garnet
Active Centre : Neodymium
Pumping
Method
: Optical Pumping
Pumping Source : Xenon Flash Pump
Optical
Resonator
: Ends of rods silver coated
Two mirrors partially and
totally reflecting
Power Output : 20 kWatts
Nature of
Output
: Pulsed
Wavelength
Emitted
: 1.064 μm
Characteristics

3. Doped Insulator laser refers to
yttrium Aluminium garnet doped with
neodymium. The Nd ion has many
energy levels and due to optical
pumping these ions are raised to
excited levels. During the transition
from the metastable state to E1, the
laser beam of wavelength 1.064μm is
emitted.
• Principle -

4. • Nd-YAG is four level solid
state laser system.
Nd – Neodymium
Y – Yttrium
Al – Aluminium
G – Garnet
• There Yttrium Aluminum
Garnet (Y3Al5O12 ) is doped
with 𝑁𝑑3+(Neodymium) ion,
with serves purpose of
Active medium.

5. Construction
• Xenon or Krypton flash
tube is taken with
necessary power supply as
a source of optical pumping
(as shown fig.)
• Nd-YAG rod and the flash
tube are kept in electrical
glass housing in such a way
that all the light produce
rod directly or after
reflective.
Resistor
Laser Rod
Flash
Tube
M1–
100%
reflector
mirror
M2 –
partial
reflector
mirror

6. • For Stimulated emission and one hand of Nd-
YAG rod is made 100% reflecting where partially.
Does the two hand act like optical cavity.
• TO dissipate, the heat produced during the
process necessary cooling system is also
arranged.

7. E1, E2, E3 – Energy levels of
Nd
E2– Meta Stable State
E0 – ground State Energy Level
Working
Energy Level Diagram of Nd– YAG LASER
Non radiative decay
Laser
1.064μm
Non radiative decay
E3
E2
E0
E1
E2
Nd

8. • When the flash tube this switch on electron in
ground state E0 of 𝑁𝑑3+ iron go to higher energy
level e3 by stimulated emission.
• As E3 is unstable exited state life time od electron
is E3 is very less. So, electron in E3 go to energy
level E2 rapidly by spontaneous emission.
• As E2 is metastable state. It is population very
soon and does population inversion is achieve
between E0 and E1.
• Now when external photon is insider electrons in
E2 go to energy level E1 by stimulated emission.

9. • During the stimulated emission from E2 to E2
light amplification also take place and so, the
light produced is laser.
• The electro in energy level E1 goes to ground
state E0 by spontaneous emission

10. Applications of Lasers
• Laser is an optical device that generates intense beam of
coherent monochromatic light by stimulated emission of
radiation.
• Laser light is different from an ordinary light. It has various
unique properties such as coherence, monochromacity,
directionality, and high intensity. Because of these unique
properties, lasers are used in various applications.
• The most significant applications of lasers include:
• Lasers in medicine
• Lasers in communications
• Lasers in industries
• Lasers in science and technology
• Lasers in military

11. Lasers in Medicine
• Lasers are used for bloodless
surgery.
• Lasers are used to destroy kidney
stones.
• Lasers are used in cancer diagnosis
and therapy.
• Lasers are used for eye lens
curvature corrections.
• Lasers are used in fiber-optic
endoscope to detect ulcers in the
intestines.
• Lasers are used to create plasma.
• Lasers are used to remove tumors successfully.
• Lasers are used to remove the caries or decayed portion of the teeth.
• Lasers are used to study the internal structure of microorganisms and
cells.
• Lasers are used to produce chemical reactions.

12. • Laser light is used in
optical fiber
communications to
send information over
large distances with
low loss.
• Laser light is used in
underwater
communication
networks.
• Lasers are used in
space communication,
radars and satellites.

13. Lasers in Industries
• Lasers are used to cut glass and quartz.
• Lasers are used in electronic industries for
trimming the components of Integrated
Circuits (ICs).
• Lasers are used for heat treatment in the
automotive industry.
• Laser light is used to collect the information
about the prefixed prices of various products
in shops and business establishments from
the bar code printed on the product.
• Ultraviolet lasers are used in the
semiconductor industries for
photolithography. Photolithography is the
method used for manufacturing printed
circuit board (PCB) and microprocessor by
using ultraviolet light.
• Lasers are used to drill aerosol nozzles and
control orifices within the required
precision.

14. Lasers in Science and Technology
• A laser helps in studying the Brownian motion
of particles.
• With the help of a helium-neon laser, it was
proved that the velocity of light is same in all
directions.
• With the help of a laser, it is possible to count
the number of atoms in a substance.
• Lasers are used in computers to retrieve stored
information from a Compact Disc (CD).
• Lasers are used to measure the pollutant gases
and other contaminants of the atmosphere.
• Lasers helps in determining the rate of rotation
of the earth accurately.
• Lasers are used in computer printers.
• Lasers are used for producing three-
dimensional pictures in space without the use
of lens.
• Lasers are used for detecting earthquakes and
underwater nuclear blasts.
• A gallium arsenide diode laser can be used to
setup an invisible fence to protect an area.

15. Lasers in Military
• Laser range finders are used to
determine the distance to an
object.
• The ring laser gyroscope is used
for sensing and measuring very
small angle of rotation of the
moving objects.
• Lasers can be used as a
secretive illuminators for
reconnaissance during night
with high precision.
• Lasers are used to dispose the
energy of a warhead by
damaging the missile.
• Laser light is used in LIDAR’s to
accurately measure the
distance to an object.