Consider an assembly of N1 and N2 atoms per unit volume with energies E1 and E2 (E2 > E1) is irradiated with photons of density ρν = N hυ, where [N] is the number of photons of frequency ν per unit volume. Then Employing the condition of thermal equilibrium ,Show that A21 = B21(8πhν3/c3) B21, and A21 are known as Einstein coefficients

Clearly explain attaining Condition of Population Inversion with figures

Clearly describe types of Lasers and their Operation and give at least two examples for each

Explain properties of Laser Radiation

What is the region enclosed by the optical cavity called?

A He-Ne laser has a gas discharge temperature of 400 K. The atomic mass of Ne (which is responsible for lasing) is kg. If the lasing wavelength is 630 nm, calculate the line shape broadening due to Doppler effect.

Explain methods for Pulsed-Laser Operation

What are the basic principles in Light-Matter Interactions in Lasers

Clearly explain Critical Laser Components

Which of the following can be used for generation of laser pulse?

• Ruby laser

• Carbon dioxide laser

• Helium neon laser

• Nd- YAG laser