Coherence, Interference and Visibility

Understand

The interference observed for a quanton, traversing more than one path, is believed to characterize its wave nature.

• Conventionally, the sharpness of interference has been quantified by its visibility or contrast, as defined in optics.
• Based on this visibility, wave-particle duality relations have been formulated for two-path interference.
• However, as one generalizes the situation to multi-path interference, it is found that conventional interference visibility is not a good quantifier.