Question

What is principle of lummer plate

Answer 1

it may be osa the principal of it

Answer 2

The Lummer–Gehrcke interferometer or Lummer–Gehrcke plate is a multiple-beam interferometer similar to the Fabry–Pérot etalon, but using light at a steep angle of incidence. ... Light bounces back and forth inside the plate, striking the faces at an angle just below the critical angle as it propagates along.

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