Question

The coherence length for Na light is 2.945×10-2 m.The wavelength of Na light is 5890 Å. Calculate %0D%0A– (i) Number of oscillations corresponding to the coherence length (ii) Coherence time.

Answer 1

To calculate the requested values, we can use the formula:

(i) Number of oscillations corresponding to the coherence length:
Number of oscillations = Coherence length / Wavelength

(ii) Coherence time:
Coherence time = Coherence length / Speed of light

Given:
Coherence length = 2.945×10^(-2) m
Wavelength of Na light = 5890 Å = 5890 × 10^(-10) m
Speed of light = 3 × 10^8 m/s

Let's calculate the values:

(i) Number of oscillations corresponding to the coherence length:
Number of oscillations = 2.945×10^(-2) m / (5890 × 10^(-10) m)

(ii) Coherence time:
Coherence time = 2.945×10^(-2) m / (3 × 10^8 m/s)

Calculating these values, we get:

(i) Number of oscillations corresponding to the coherence length:
Number of oscillations ≈ 4.996 × 10^7 oscillations

(ii) Coherence time:
Coherence time ≈ 9.817 × 10^(-11) seconds

Therefore, the calculated values are approximately:
(i) Number of oscillations corresponding to the coherence length: 4.996 × 10^7 oscillations
(ii) Coherence time: 9.817 × 10^(-11) seconds