Question

write a final statement about the necessity of using the interferometer relating to wavelength of light, monochromatic light, and sodium doublet

Answer 1

With an interferometer, we can measure distances directly in terms of wavelength of light used, by counting the interference fringes. Here for example - we consider michelson's interferometer in which Light from a monochromatic light source is divided by a beam splitter which is oriented at an angle 45° to the beam, producing two beams of equal intensity. The transmitted beam travels to mirror and it is reflected back to Beam Splitter. 50% of the returning beam is then reflected by the beam splitter and strikes the screen. The reflected beam travels to the other mirror , where it is reflected. 50% of this beam passes straight through beam splitter and reaches the screen. This is where we observer our interference phenomena. Remember all interferometers superimpose beams of light to create interference.