Scenario: Standard Double Slit
P(x) = I₁+I₂+2√I₁I₂·cos(Δφ)
Δφ = 2πd·sinθ/λ
Single-slit envelope:
sinc²(πa·sinθ/λ)
Which-path: Δφ random
→ fringes vanish
Eraser: restore coherence
→ fringes reappear
Δφ = 2πd·sinθ/λ
Single-slit envelope:
sinc²(πa·sinθ/λ)
Which-path: Δφ random
→ fringes vanish
Eraser: restore coherence
→ fringes reappear