In this presentation, we talked about how lasers are produced and their function in the medical fields.

1. Laser in medicine
Supervisor: Dr.Anan Hussein
Prepared By: Zakia Abu Abied

2. Outline:
 Introduction
 Basic Theory
 What is laser ?
 Basic Concepts
 Production of Laser
 Characteristics of Laser
 Types of Lasers
 Laser Application
 Conclusion

3. Introduction
 Today, lasers are employed by a wide range of professions, but one of
the most important applications of laser technology has been in
medical.
 Lasers have entered most medical specialties in the last half century,
including dermatology, ophthalmology, dentistry, urology,
gynecology and cardiology, due to their speed and precision. The
laser has changed disease diagnosis and therapy in many ways.

4. What is laser ?
Light
Amplification By
Stimulated
Emission Of
Radiation

5. Basic Theory
 Atom composed of a nucleus and electron cloud
 If an incident photon is energetic enough, it may be absorbed by
an atom, raising the latter to an excited state.
 It was pointed out by Einstein in 1917 that an excited atom can be
revert to a lowest state via two distinctive mechanisms:
 spontaneous emission
 stimulated emission.

6. Basic Concepts
 Laser is a narrow beam of light of a
single wavelength (monochromatic) in
which each wave is in phase (coherent)
with other near it.
 Laser apparatus is a device that produce
an intense concentrated, and highly
parallel beam of coherent light.

7. Characteristics of Laser
 Monochromatic
 Coherent
 Directional

8. →Production of Laser
Spontaneous emission:
 Let us consider an atom that is initially in level 1 and interacts with an
electromagnetic wave of frequency n. The atom may now undergo a transition to
level 2, absorbing the required energy from the incident radiation. This is well-
known phenomenon of absorption.
 Each electron can drop back spontaneously to the ground state emitting photons.
 Emitted photons bear no incoherent. It varies in phase from point to point and
from moment to moment.
 e.g. emission from tungsten lamp.

9. →Production of Laser
Stimulated emission:
 Each electron is triggered into emission by the
presence of electromagnetic radiation of the proper
frequency. This is known as stimulated emission and
it is a key to the operation of laser.
 e.g. emission from Laser

10. →Production of Laser
population inversion:
 Generally electrons tends to (ground
state). What would happen if a substantial
percentage of atoms could somehow be
excited into an upper state leaving the
lower state all empty? This is known as a
population inversion. An incident of
photon of proper frequency could then
trigger an avalanche of stimulated
photon- all in phase (Laser).
 If E1 < E2 Then N1 > N2
 If E1 < E2 and N1 < N2 This is
called "population inversion".

11. Type of Laser
 According to Excitation process
 Pulsed Laser
 Continuous Laser
 According to the Lasing Medium
 Gas Lasers
 Dye (fluid) Lasers
 Metal-vapor Lasers
 Solid Lasers
 Semiconductor Lasers

12. Application of
Laser
SCIENCE
MACHINING
COMMUNICATIONS
SECURITY/MILITARY
MEDICINE

13. Application of
Laser
 Laser in medicine has helped to work with high
accuracy by focusing on a small area and reducing
damage to nearby areas of the body, where pain,
bloating and tissue damage are lower than
traditional surgeries, but laser treatment can be
expensive and requires many treatment sessions.
Laser in MEDICINE

14. Laser therapy for cancer (Oncology)
 Lasers can be used to treat cancer in two ways:
o Using heat to reduce or eliminate a tumor
o To activate a photosensitizing agent, a chemical that destroys
just the cancer cells. (This is referred known as PDT, or
photodynamic treatment.)

15. Laser lithotripsy
 The treatment of laser lithotripsy is used to break up kidney stones
in the urinary system. It's done with a scope that can be inserted
into the urinary tract tubes which mean no incisions are required.
The kidney stones are broken down into smaller bits by the laser,
which can then be removed by the surgeon or passed through the
urine

16. LASIK Eye Surgery
 The word LASIK mean (Laser-Assisted In Situ Keratomileusis)
 Lasik uses an excimer laser (an ultraviolet laser) to remove a small
amount of corneal tissue. This gives the cornea a new shape so that light
rays are focused clearly on the retina. Lasik causes the cornea to be
thinner .

17. Laser in Cosmetic medicine
• Laser hair removal • Laser to remove birthmarks
 One of the most common uses is hair removal  Lasers are utilized in a variety of cosmetic
operations, including the elimination of
birthmarks, the damaged skin is treated with
low-energy green lasers.

18. Conclusion
 Finally, I conclude that lasers play an important role in
medicine.
 Laser action is preceded by three processes namely
absorption, stimulated emission and population
inversion .
 Lasers are device which produce beams of light which
are very intense, directional and Pure in color.

19. The End
THANKS FOR YOUR ATTENTION