Phase-measurement uncertainty Δφ ≥ 1/√N for N independent photons in a coherent state — the noise floor of classical interferometry. Squeezed light or N00N states can beat this limit (Heisenberg-limited Δφ ~ 1/N).
Phase-measurement uncertainty Δφ ≥ 1/√N for N independent photons in a coherent state — the noise floor of classical interferometry. Squeezed light or N00N states can beat this limit (Heisenberg-limited Δφ ~ 1/N).