Question

the spectral width of red line of cadmium of wave length 6943A°is 0.01A°. calculate the spectral purity factor , coherence time & coherence length​

Answer 1

Explanation:

Some Characteristics of Time-Resolved Spectra. 15.3. ... of three cadmium lines to eight significant figures. ... length standard is an emission line of krypton 86 which has a wavelengths

Answer 2

Answer:

The spectral purity factor of the red line of cadmium is 6.943×10⁵, Coherence time is

1.6 × 10⁻⁸sec and coherence length is 0.482m.

Explanation:

This is a formula-based question.

We will use three relations to solve this question. Let's look at it one by one.

Spectral purity factor(Q) is given as,

$Q=\frac{\lambda}{\Delta \lambda}$                     (1)

λ= wavelength of light

Δλ=spectral width

Coherence length(L) is given as,

$L=Q\lambda$                     (2)

Coherence time(T) is given as,

$T=\frac{L}{c}$                       (3)

c= speed of light=3×10⁸m/s

The values given in the question are,

λ=6943A°

Δλ=0.01A°

By using equation(1) we get,

$Q=\frac{6943A\textdegree}{0.01A\textdegree}=6.943\times 10^5$

By using equation (2) we get,

$L=6.943\times 10^5 \times 6943A\textdegree=0.482m$

By using equation (3) we get,

$T=\frac{0.482}{3\times 10^8}=1.6\times 10^-^8sec$

Hence, the spectral purity factor of the red line of cadmium  is 6.943×10⁵, Coherence time is

1.6 × 10⁻⁸sec and coherence length is 0.482m.