UNIT 1

How many types of coherence schemes are available?

• 1

• 2

• 3

• 4

Which one of the following represents the temporal coherence?

• Associate with the difference in frequencies of the two waves

• Associate with the location of the two waves

• Both a and b

• None of the above

Which one of the following represents the spatial coherence?

• Associate with the difference in frequencies of the two waves

• Associate with the location of the two waves

• Both a and b

• None of the above

Which one of the following is a type of coherence

• Q-Switching

• Temporal

• Direct conversion

• Modelocking

Temporal coherence also called as or similar with______

• Longitudinal

• transverse

• Dispersion

• Population inversion

Spatial coherence also called as_________

• Population inversion

• Dispersion

• Transverse

• Longitudinal

What distribution law will be useful to find the population from the energy levels

• Maxwell-Boltmann distribution law

• Bose-Einestein distribution law

• Fermi-Dirac distribution law

• none of the above

In 1917, __________ laid the foundation for the laser when he introduced the concept of stimulated emission

• Newton

• Scholaw

• Tesla

• Einstein

In Stimulated Emission, which among the following parameters of a generated photon is/aresimilar to the photon of the incident wave?

• Phase

• Polarization & direction of travel

• Frequency

• All of the above

Stimulated absorption is

• Transition of atom from lower energy state to higher energy state due to incident photon.

• transition of atom from lower energy state to higher energy state without external energy

• transition of atom from higher energy state to lower energy state

• transition of atom from meta stable state to ground state