Acronym for LASER is

• Light Absorption by Stimulated Emission of Radiation

• Light Amplification by Stimulated Emission of Radiation

• Light Alteration by Stimulated Emission of Radiation

• Light Attenuation by Stimulated Emission of Radiation

Which of the following statements are true?

1. LASER is used as optical source in single mode fibers.
2. LASER lights are highly incoherent.

• 1. is true and 2. is false

• 1. is false and 2. is true

• Both 1 & 2 are true

• Both 1 & 2 are false

Naturally occuring process in a LASER is

• Stimulated Emission

• Absorption

• Spontaneous Emission

• Population Inversion

The process in which the electrons in the ground state are vibrated to the excited states by providing extra energy from energy sources is called as

• Population Inversion

• Spontaneous emission

• Stimulated emission

• Pumping

The coherent nature of light from LASER is due to

• Spontaneous emission

• Stimulated Emission

• Absorption

• Pumping

Light amplification in LASER is achieved by

• Population inversion

• Stimulated emission

• Spontaneous emission

• Pumping

Minimum number of energy states required to achieve population inversion is

• 1

• 2

• 3

• 4

The lifetime of electrons are more in

• Pump state

• Excited state

• Meta stable state

• Ground state

In a LASER diode,the light output is taken from

• P-layer

• Active layer

• N-layer

• Mirror polished reflecting surface

High optical gain in LASER diode is due to

• Heavily doped P-layer

• Heavily doped N-layer

• Active layer

• Reflective surfaces