Return to Eq. (12.21) and separate it into two terms representing a coherent and an incoherent contribution, the first arising from the superposition of two coherent waves with irradiances of |?^?₁₂(?)|I₁ and|?^?₁₂(?)|I₂ having relative phase of ?₁₂(?) - ?, and the second from?

the superposition of incoherent waves of irradiance [1 - |?^?₁₂(?)|]I_1?and [1 - |?^?₁₂(?)|]I₂. Now derive expressions for I_coh/I_incoh and for I_incoh/I_total. Discuss the physical significance of this alternative formulation and how we might view the visibility of fringes in terms of it.

Transcribed Image Text:

I = 1 + I½ +2 Vh½| ¥12(7)| cos [a12(7) – 4] (12.21) -