Question

A laser source has a bandwidth of 30GHz (a) Calculate the coherence length of the source b) What is the time separation of sections of the light wave that can still interfere? source, can have?

Answer 1

Step-by-step explanation:

It is given that,

Bandwidth of a laser source,
`f=30\ GHz=30* 10^9\ Hz`

(b) Let t is the time separation of sections of sections of the light wave that can still interfere. The time period is given by :

`T=(1)/(f)`

`T=(1)/(30* 10^9)`

`T=3.33* 10^(-11)\ s`

(a) Let h is the coherence length of the source. It is given by :

`l=c* T`

c is the speed of light

`l=3* 10^8* 3.33* 10^(-11)`

l = 0.0099 m

Hence, this is the required solution.