1. Tardigrade
  2. Question
  3. Physics
  4. In Michelson interferometer sharp circular fringes are observed. A very thin plate with optical thickness equal to twenty wavelengths of the light being used in inserted into one of the interferometer arms. What is the number of bright fringes that cross the field of view?

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. In Michelson interferometer sharp circular fringes are observed. A very thin plate with optical thickness equal to twenty wavelengths of the light being used in inserted into one of the interferometer arms. What is the number of bright fringes that cross the field of view?

CMC MedicalCMC Medical 2015

Solution:

Optical thickness of plate $ =(\mu -1)\,t=20\lambda $ We know that number of fringes crossing the field of view are given by $ n=\frac{2\,(\mu -1)\,t}{\lambda } $ $ =\frac{2\times 20\,\lambda }{\lambda }=40 $