Abstract
The Copenhagen interpretation, in which the core concepts are Heisenberg's uncertainty principle and nonlocal EPR correlation, has been long discussed. Second-order anticorrelation in a beam splitter represents the origin of these phenomena and cannot be achieved classically. Here, the anticorrelation of nonclassicality in a beam splitter is interpreted using the concept of coherence. Unlike the common understanding of photons having a particle nature, anticorrelation is rooted in the wave nature of coherence optics, described by coherence optics, wherein quantum superposition between two input fields plays a key role. This interpretation may pose fundamental questions about the nature of nonclassicality and pave a road to coherence-based quantum information.