"length of electromagnetic waves"

¡Escribe tu texto aquí!31. Define light Polarization and describe the different types of polarization that we can have.

Polarization of a light ia a process by which an unpolarized light (any light which is having its Vibration in any random direction) is changed to a polarized light (light Having waves vibrating in a particular direction). Polarization is done in Order to produce plane polarized light amd is done by reflection, refraction o Other methods.

Types of polarizaion:

 - Plane polarization.

 - Circular polarization

 - Elliptical polarization

 33- Explain the phenomenon of stimulated Emission and laser operation.

Stimulated Emission is the process by which an incoming photon of a specific frequency can Interact with an excited atomic electron (or other excited molecular state), Causing it to drop to a lower energy level. The liberated energy transfers to The electromagnetic field, creating a new photon with a phase, frequency, Polarization, and direction of travel that are all identical to the photons of The incident wave.

 If it is realized with lots of electrons, a laser is created.

34.- List The different techniques to generate laser pulses. Estimates the duration of The pulses in each case.

Thermal Process: > picosecond.

Ablation: <picosecond.

Melting Process: ????= 4∗????∗????????ℎ????????????=????????????????????.

Effective Fusion: 10-6s.

CO2 laser: 1ms

36- Describe and Explain the different industrial applications of the laser.

Matter elimination Processes: cut, punch and mark. -Light matter interaction: modify the structure Of the material. -Melting: melt materials.

-Evaporation: Material vaporizes. -Ablation: exploits some of the material