Question

Two plane mirrors forming a resonant cavity in a He Ne laser are at a distance of 0.5 m.

find the frequency separation between two consecutive modes in longitudinal cavity.​

Answer 1

Answer:

4564

Explanation:

Answer 2

Given:

Two plane mirrors forming a resonant cavity in a He Ne laser are at a distance of 0.5 m.

i.e. l = 0.5 m

To find:

The frequency separation between two consecutive modes in the longitudinal cavity

i.e. $\displaystyle \mathbf {\Delta v_m }$ =?

Explanation:

The frequency separation between two consecutive modes

$\displaystyle \mathbf {\Delta v_m = \frac{c}{2l} }$

where

c= speed of light = $\displaystyle \mathbf {3 \times }10^8 m}}$

$\displaystyle \mathbf {\Delta v_m = \frac{3 \times 10^8}{2 \times 0.5} }$

         = $\displaystyle \mathbf {3 \times }10^8 }}$

         = $\displaystyle \mathbf {0.3 \times }10^9}}$ Hz

         = 0.3 G Hz

The frequency separation between two consecutive modes in the longitudinal cavity is 0.3 G Hz