Question

EXAMPLE 5. With a He-Ne laser (a = 632.8 nm) the fringes in Michelson
interferometer remained visible when the path difference was increased
upto 8m. Deduce the lower limits of the following:
(i) Coherence length
(ii) Coherence time
(iii) Spectral line width
(iv) Purity factor Q​

Answer 1

Answer:

1) Assume we move one mirror of a Michelson interferometer through a ...

2) A He-Ne laser of wavelength 632.8 nm is used as a source of a .

. 3) A Newton interferometer is being used to test a lens.