2. Light Amplification by Stimulated Emission of
Radiation.
A laser is a device that emits light through a
process of light amplification based on
the stimulated emission of electromagnetic
radiation.
3. Laser light has three characteristics that
are different from ordinary light.
1. Directional property
2. Monochromatic property.
3. Coherent property.
5. Laser light is emitted as a relatively
narrow beam in a specific direction.
6. The light from a laser is said to
be coherent, which means the wavelengths
of the laser light are in phase in space and
time.
7.
8. The light moves through the medium
between the two mirrors that reflect the
light back and forth between them.
One of the mirrors, however, only partially
reflects the light, allowing some to escape.
The escaping light makes up the laser beam.
9. Slope efficiency is the important property of
laser.
The slope efficiency is the slope of this line.
Slope efficiency can similarly be defined in
terms of output and input energies instead of
powers.
This makes it applicable to pulsed lasers.
10. Less expensive.
More compact.
Welding of complicated joint geometry.
Low heat application, therefore minor
changes in microstructure
Low thermal distortion.
11. Have shorter coherent length.
Laser equipment is expensive.
12. Laser printers,
Laser fax machines
Supermarket bar code readers all use diode
lasers
Eye surgery.
Military application.
13. PI characteristic of laser diode.
Plotting the current in x-axis.
Power in the Y-axis.